THERMOGENIC SUPPLEMENT USAGE IN COLLEGE STUDENTS
A thesis submitted to the Kent State University
College of Education, Health, and Human Services
in partial fulfillment of the requirements
for the degree of Master of Science
Luc LaBonte
December 2015
Thesis written by
Luc LaBonte
B.S., Kent State University, 2014
M.S., Kent State University, 2015
Approved by
_______________________, Director, Master Thesis Committee
Natalie Caine-Bish
_______________________, Member, Master Thesis Committee
Amy Miracle
_______________________, Member, Master Thesis Committee
Karen Gordon
Accepted by
_______________________, Director, School of Health Sciences
Lynne E. Rowan
_______________________, Interim Dean, College of Education, Health, and Human
Mark A. Kretovics
Services
ii
LABONTE, LUC L., M.S., December 2015
Nutrition and Dietetics
THERMOGENIC SUPPLEMENT USAGE IN COLLEGE STUDENTS (113 p.p.)
Director of Thesis: Natalie Caine-Bish, Ph.D., R.D., L.D.
The purpose of this study was to determine the thermogenic supplement usage in
college students enrolled at a Northeast Ohio State University. There were two
hypotheses: (a) there is a significant difference in thermogenic supplement usage between
males and females and (b) there is a significant difference in thermogenic supplement
usage between the different exercise categories of participants. Data was collected
through a Qualtrics (version 2.4) online survey. The questionnaire included an
introduction, demographics, supplement usage, and a source of information sections. The
website link was emailed to a randomized sample of 3,098 students provided by Kent
State University Institutional Research. The data was analyzed using SPSS software
version 22 IBM, New York. Descriptive data was analyzed to determine frequency,
means, and standard deviations. A 2x3 Factorial analysis of variance was used. There
were two gender levels – male and female. There were three athlete category levels –
non-athlete, recreational athlete, and competitive athlete. A Tukey post hoc analysis was
used to determine significance between groups. The level of significance was p < 0.05.
Result: data was used from 108 participants. Both hypotheses were partially accepted.
Gender significant differences were: (a) males consume caffeinated tea more frequently
than females, and (b) females use caffeinated coffee for the reasons of taste/enjoyment
and general energy than males. Athlete category significances were: (a) non-athletes
consume caffeinated tea and nutritional supplements/diet pills more frequently than other
athlete groups, (b) there is a difference in reasons for usage related to general energy
between all athlete groups (there was no interaction significance), and (c) competitive
athletes use nutritional supplements/diet pills more for taste/enjoyment and
convenience/habit than any other group.
ACKNOWLEDGMENTS
I would like to give my sincerest gratitude to my committee: Dr. Natalie CaineBish, Dr. Amy Miracle, and Dr. Karen Gordon.
Dr. Natalie Caine-Bish, thank you for your patience, support, and guidance
throughout my undergraduate and graduate career at Kent State University. Without your
assistance over the past five years, I would not have been able meet all of my goals in
such a timely manner. Dr. Amy Miracle and Dr. Karen Gordon, thank you for the
constructive criticism on my thesis and all other academic opportunities that you have
provided me.
I would also like to thank my family, friends, and classmates that have helped me
throughout my academic career and thesis development. These individuals have
provided me with moral support and encouragement throughout this journey.
Finally, I would like to thank all of the participants of this study. Without their
time and participation, none of this would be possible.
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TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS ................................................................................................. iii
LIST OF TABLES ............................................................................................................. vi
CHAPTER
I.
INTRODUCTION ......................................................................................................1
Problem Statement ......................................................................................................4
Purpose Statement ......................................................................................................5
Hypothesis...................................................................................................................6
Definition of Terms.....................................................................................................6
II.
REVIEW OF LITERATURE .....................................................................................9
Regulation on Supplementation ..................................................................................9
Reasons for Supplement Use and Influencing Factors .............................................11
Common Types of Supplements ...............................................................................14
Vitamin and Mineral Supplements .....................................................................15
Protein and Amino Acid Supplements ................................................................16
Ergogenic Aids....................................................................................................20
Creatine .........................................................................................................21
Sports Beverages and Gels............................................................................24
Caffeine .........................................................................................................26
Thermogenic Supplements..................................................................................29
Ephedrine ......................................................................................................31
Synephrine ....................................................................................................34
Less Dangerous Thermogenics .....................................................................36
Green tea .................................................................................................36
Yerba maté ..............................................................................................38
Gender Differences in Supplement Usage ..........................................................40
Sources of Supplement Information ...................................................................41
III.
METHODOLOGY ...................................................................................................43
Purpose......................................................................................................................43
Hypothesis.................................................................................................................43
Study Design .............................................................................................................43
Participants ................................................................................................................44
Questionnaire ............................................................................................................44
Demographics ...........................................................................................................45
Supplement Usage ....................................................................................................45
Procedure ..................................................................................................................47
Statistical Analysis ....................................................................................................48
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TABLE OF CONTENTS continued
IV. JOURNAL ARTICLE ..............................................................................................50
Introduction ...............................................................................................................50
Methodology .............................................................................................................52
Participants ..........................................................................................................53
Questionnaire ......................................................................................................53
Demographics .....................................................................................................54
Supplement Usage ..............................................................................................54
Procedure ............................................................................................................55
Data Analysis ......................................................................................................56
Results .......................................................................................................................57
Discussion .................................................................................................................75
Subject Characteristics ........................................................................................75
Gender ................................................................................................................76
Athlete Category .................................................................................................79
Strengths ...................................................................................................................82
Limitations ................................................................................................................83
Recommendations for Future Research ....................................................................85
Applications ..............................................................................................................85
Conclusion ................................................................................................................88
APPENDICES ...................................................................................................................89
APPENDIX A. CONSENT FORM ..........................................................................90
APPENDIX B. SURVEY QUESTIONNAIRE ........................................................92
REFERENCES ................................................................................................................105
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LIST OF TABLES
Table
Page
1
Survey participant demographics of college students consuming thermogenic
supplements (N = 108) ..............................................................................................58
2
Types of thermogenic supplements used in college students reporting use .............59
3
Frequency of use of thermogenic supplements in college students consuming
thermogenic supplements..........................................................................................60
4
Gender differences in supplementation frequency in college students consuming
thermogenic supplement usage .................................................................................61
5
Gender differences in reasons for caffeinated coffee usage for college students
consuming thermogenic supplements (N = 80) ........................................................62
6
Gender differences in reasons for caffeinated tea usage for college students
consuming thermogenic supplements (N = 61) ........................................................63
7
Gender differences in reasons for energy/sports drink usage in college students
consuming thermogenic supplements (N = 22) ........................................................64
8
Gender differences in reasons for nutritional supplements/diet pills usage in college
students consuming thermogenic supplements (N = 13) ..........................................65
9
Supplementation frequency differences between college athletes groups consuming
thermogenic supplements..........................................................................................67
10
Differences in reasons for usage of caffeinated coffee between college student
athlete groups consuming thermogenic supplements (N =80)..................................69
11
Differences in reasons for usage of caffeinated tea between college student athlete
groups consuming thermogenic supplements (N = 60) ............................................71
12
Differences in reasons for usage of sports/energy drinks between college student
athlete groups consuming thermogenic supplements (N = 22).................................73
13
Differences in reasons for usage of nutritional supplements/diet pills between
college student athlete groups consuming thermogenic supplements (N = 13)........75
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CHAPTER I
INTRODUCTION
The use of dietary substances has been used in past years for the purpose of
increasing health and wellness, exercise/athletic performance, lose body fat or manage
weight, increase muscle mass, prevent or treat medical problems, improve the immune
system, enhance alertness, and reduce stress (Gosten & Correia, 2010). The use of diet
dates as far back as 776 BCE where Greek athletes used substances like dried figs,
mushrooms, and strychnine to help enhance physical performance (Calfee & Fadale,
2006). In the last few centuries, several discoveries have been made identifying nutrients
that have beneficial effects on human bodies. Generally, the term dietary or nutritional
supplement has been used to describe these nutrients.
The U.S. Food and Drug Administration (FDA) defines a nutritional/dietary
supplement as a product intended to supplement the diet that typically contains one or
more of the following dietary ingredients: (a) a vitamin, (b) a mineral, (c) an herb or other
botanical, (d) an amino acid, (e) a dietary substance for use by man to supplement the diet
by increasing total dietary intake, or (f) a concentrate, metabolite, constituent, extract, or
combination of any ingredient described in clause (a), (b), (c), (d), or (e). Included in
nutritional supplements are ergogenic aids (e.g. creatine, protein powders, etc.) (FDA,
2015). Some general categories of nutritional supplements used include vitamin and
mineral supplements, protein and amino acid supplements, ergogenic aids, and
thermogenic supplements.
1
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These supplements can be taken in forms such as tablets, powders, capsules, edible bars,
and liquids (FDA, 2015).
The nutritional supplement business currently resides as a multi-billion dollar
industry. Before the passing of the Dietary Supplement and Health Education Act
(DSHEA) in 1994, this industry in the U.S. equaled around four billion dollars and in a
little over a decade it had grown to over 22 billion dollars (Nutrition Business Journal
Research, 2006; Saldanha, 2007; Schneeman, 2005). As of 2012, U.S. citizens spend
around 28 billion on dietary supplements per year (Cohen, 2012).
Along with product sales, the number of consumers may be increasing. A large
portion of the population currently engages or has previous engaged in supplement use.
Data collected from the National Health and Nutrition Examination Survey (NHANES)
observed that between the years of 2003-2006, 49% of individuals over the age of one
year old consumed dietary supplements and 54% of adults reported supplement use
(Bailey et al., 2010). In relation to college students, one study reported that 89% of
collegiate athletes are taking or have previously taken nutritional supplements (Froiland
et al., 2004). Along with this research, other studies have shown that supplementation is
typically self-prescribed and that over half of physically active supplement users do not
consult with any professional for usage recommendations (Goston & Correia, 2010).
The intent of the individuals that are using nutritional supplements is in the belief
that the products will: improve exercise performance, increase power/strength, gain
muscle, lose weight/fat, maintain health and wellness, and prevention of disease (Blanck
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et al., 2007; Calfee & Fadale, 2006; Froiland et al., 2004; Goston & Correia, 2010; Stasio
et al., 2008). Though there are several motives behind supplement usage, there are
numerous factors (gender for example) that will contribute to specific usage. Studies
suggest that males tend to place more emphasis on the athletic performance-enhancing
factors of supplements whereas females tend to be more concerned with the health
benefits (Froiland et al., 2004; McDowall, 2007; Slater et al., 2003; Sobal and Marquart,
1994).
One specific area of interest listed above in dietary supplements is thermogenic
supplementation. Thermogenics are often marketed with the purpose to assist consumers
achieve a negative caloric balance, increase weight loss, and improve body composition
through increasing the body’s metabolic rate (often resulting in an increase in body
temperature or heat release) (Kovacs & Mela, 2006). Some popular examples of
substances that are often included in the thermogenic supplement category include:
caffeine, synephrine, ephedra/ephedrine, green tea, garcinia cambogia, yohimbine, yerba
maté, and capsaicin. Many of these samples have been extensively researched to
quantify the effects on metabolism, and some of them have even been removed from the
market by the Food and Drug Administration (FDA) due to potential dangerous side
effects related to cardiac and mental stimulation issues associated with excessive or
incorrect consumption (Calfee & Fadale, 2006). Abusing thermogenic supplements can
be particularly dangerous because these substances often relate to increasing blood
pressure, heart rate, and other physiological effects that increase caloric expenditure.
Side effects of some popular thermogenic supplement ingredients include: hypertension,
4
tachyarrhythmia, variant angina, cardiac arrest, QT prolongation, ventricular fibrillation,
myocardial infarction, dizziness, cerebral vascular accident, arrhythmia, insomnia,
myocardial infarction, seizure, psychosis, and death (Astrup et al., 1992; Calfee &
Fadale, 2006; Dwyer et al., 2005; Rossato et al., 2011).
Problem Statement
Thermogenics supplement usage requires more attention that it receives. There
may not be adequate federal regulation on the information marketed for these products
and health claims can at times be misleading. Federal agencies cannot always guarantee
the safe and recommended usage for these products (especially when these products first
enter the market). In certain circumstances, some nutritional supplement usage can be
dangerous. Though most supplements are safe and side effects are not severe (e.g.
vitamin and mineral supplements), these can often be gateways into more hazardous
nutritional or ergogenic practices like overdosing or abusing dietary supplements or drugs
and anabolic steroid use (McDowall, 2007). The outcomes from dietary supplement
abuse can be devastating to the health of the consumers and has led the FDA to outlaw
commercial retailing of certain supplements.
In addition to the dangers associated with use and abuse, the population of
supplement consumers continues to grow. In the young adult population (especially
those who actively exercise), supplement usage has been gradually increasing, with rates
as high of 89% of collegiate student athletes are taking or have previously taken
nutritional supplements (Froiland et al., 2004). Furthermore, the data reported in some
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circumstances over half of college aged students who are supplement users do not consult
with any professional for advice or usage recommendations (Goston & Correia, 2010).
With thermogenic supplements being a category of misuse as demonstrated by only
30.2% of weight loss supplements (typically thermogenics) users consulted with their
doctor about using these products (Blanck et al., 2007). In addition, two studies
conducted on a college athlete population discovered that athletes were more likely to
obtain supplement information and advice from family, friends, and fellow athletes than
trained professionals (coaches, athletic trainers, dietitians/nutritionists, and physicians)
(Froiland et al., 2004; Herbold et al., 2004). Individuals may not be completely truthful
during surveys in providing their supplementation habits due to fear of legal or
organizational consequences of admitting potentially illegal or banned supplements
leading to thoughts that available data on usage under estimates thermogenic usage.
The dangers of thermogenic supplement misuse combined with the amount of
individuals consuming supplements while not seeking professional guidance or obtaining
supplement advice from non-reputable sources is a problem that must be addressed to
ensure the health of college students, athlete or non-athlete alike. The risk of dangerous
supplement practices requires more research to determine specific habits of this
population.
Purpose Statement
The purpose of this study is to determine the thermogenic supplement usage
(which type of supplement is being used, servings per week, and reasons for use) in male
6
and female, athletes and non-athletes, college students enrolled at a Northeast Ohio State
University.
Hypotheses
1. There is a significant difference in thermogenic supplement usage between males
and females.
2. There is a significant difference in thermogenic supplement usage between the
different exercise categories of participants.
Definition of Terms
Thermogenic Supplement: A nutritional/dietary supplement that is advertised to increase
the basal metabolic rate and energy expenditure primarily to create a negative caloric
balance for weight loss and improving body composition through reduction of body fat
(Kovacs & Mela, 2006).
Thermogenic supplement usage: Which type of thermogenic supplement is being used,
servings per week, and reasons for use.
Exercise Categories:

Athlete: A general term for a person with the natural or acquired traits such as
strength, agility, speed, and endurance that are necessary for physical exercise or
sports, especially those performed in competitive contexts. For this study, the
term athlete will be broken down into sub-divisions.
7

Recreational Athlete: A person who exercises for general purposes of health,
wellness, personal enjoyment or stress relief, or improvement of physical
appearance. This is the category of exercisers generally does not participate in
athletic competitions or has exercise performance as a top priority.

Competitive Athlete: A person who exercises for the reasons associated with a
Recreational Athlete, but with a far greater emphasis on improving athletic-traits
and competition. These athletes compete to improve their personal best times,
win single or team related events, and/or qualify for or participate in elite
competitions (non-NCAA affiliated). Examples of this category include:
Triathletes, Runners (race-oriented), or an organizational team sport (Football,
Basketball, etc.).

National Collegiate Athlete Association Athlete: A person who is a full-time
college student participating in sports through a National Collegiate Athlete
Association (NCAA) team at the university of attendance. This individual may
exercise for the same reasons associated with a Recreational and Competitive
athlete. An athlete participating in NCAA sports are typically considered to be at
the elite level.
College Student: A person who is (a) enrolled as a full-time student at a traditional
college or university (can be pursuing a baccalaureate degree or a graduate degree), and
(b) over the age of 18 years old.
Kent State University: A public research university located in Kent, Ohio.
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Kent State University Student: A person who is (a) enrolled as a full-time or part-time
student at Kent State University (can be pursuing a baccalaureate degree or a graduate
degree), and (b) over the age of 18 years old.
CHAPTER II
REVIEW OF LITERATURE
Regulation on supplementation
Before the Dietary Supplement Health and Education Act (DSHEA) in 1994,
there was no significant regulation on dietary supplements. The legislation in this act
established that dietary supplement regulation falls under the jurisdiction of two federal
organizations: The Food and Drug Administration and Federal Trade Commission (FTC)
(FDA, 2015; FTC, 2001). Firstly, supplement manufacturers are not required to any
agency approval before production or sale of dietary supplements. Before these products
can head to market federal law dictates that every dietary supplement must be labeled
with its identity as a supplement. The label must contain the terms “Dietary Supplement”
or with a similar term that can substitute the word dietary with a description of the
specific ingredient (e.g. herbal supplement or calcium supplement) (FDA, 2015).
Though this helps clarify the identity of the product for consumers, the FDA does not
require the supplement to be proven safe until they are marketed. In addition to this, the
law does not require the manufacturer or seller to prove to FDA's satisfaction that the
claim is accurate or truthful before it appears on the product. Because of the loose
regulations, this requires consumers to be educated on the products before usage to
ensure safety. In general, the FDA has little power until after the product is introduced in
the market place. The FDA has responsibilities related to monitoring mandatory
reporting of threatening adverse side effects by supplement firms and voluntary adverse
9
10
side effects reporting by consumers and health care professionals. Also (if the resources
are available), the FDA may review product labels and other product information, such as
package inserts, accompanying literature, and Internet promotion (FDA, 2015). Only
when the supplement presents a significant risk of harmful effects can the FDA may take
action towards the manufacturer (FDA, 2015). Along with the FDA, the Federal Trade
Commission has a small part to play in the regulation of supplements. Any advertising
(radio, internet, printed resources, etc.) falls under the FTC’s jurisdiction. The role of the
FTC is this context is to ensure that the advertising of these products must be truthful, not
misleading, and substantiated (FTC, 2001). These statements may be nebulous and the
FTC cannot always take action towards these companies. In general, the FTC defends
any determinations of the FDA on whether there is adequate evidence to support health
claims on products (FTC, 2001). The FTC’s ruling often times depends on the FDA, thus
creating an environment that these two agencies work closely together to ensure the
health and safety of consumers.
Along with regulation at the federal level, there is also regulation in sporting
events. The primary agency involved in supplement regulation in athletics is the World
Anti-Doping Agency (WADA). The goal of WADA is to “lead a collaborative
worldwide movement for doping-free sport” (WADA, n.d.). WADA was created after
the publication of the World Anti-Doping Code in 2004. This document is the core
standard for policies, rules, and regulations within sporting organizations around the
world; notable organizations include: the International Olympic Committee (IOC),
National Collegiate Athletic Association (NCAA), and the Olympic Sport International
11
Federations (NCAA, n.d.; WADA, n.d.). This code continues to be updated and has been
revised several times since the first publication. This code works with five international
standards of maintaining a prohibited substance list, testing and investigation of cases,
providing valid lab test results, granting therapeutic use exemptions to athletes, and
guaranteeing privacy and protection of health information (WADA, n.d.). The prohibited
list that is maintained by WADA includes several different categories of
drugs/supplements, one of which includes stimulants (some of which are also
thermogenic in nature).
NCAA athletes must abide by the code and regulations established by WADA.
Approximately 4.5 million dollars per year is used to analyze approximately 13,500
samples through the NCAA drug testing program (NCAA, n.d.). The testing procedures
(typically urinalysis) are conducted by an independent certified collection agency under
the WADA guidelines. In NCAA, the policy for a positive result on drug testing results
in a loss of one full year of eligibility for the first offense and are withheld from
competition for a full season. A second positive result for performance enhancing drug
usage will render the athlete permanently ineligible (NCAA, n.d.). The NCAA places
responsibility on the athlete to check with appropriate athletics staff and the NCAAWADA guidelines before use of any supplement.
Reasons for Supplement Use & Influencing Factors
There are several influencing factors for individuals complementing diet with
nutritional supplements. Some of the most popular reasons include exercise performance
(and related factors), weight loss, and health and wellness.
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Increasing exercise performance is a very popular reason for supplementing.
Individuals use supplements to increase power, speed, and strength as well as increase
muscle mass. These motives are popular for athletes as well as recreational gym users.
One study conducted on division I college athletes discovered that 42.5% of participants
supplemented for power/strength and 41.5% use for muscle gain (Froiland et al., 2004).
Another study performed on gym frequenting supplement consumers reported that 38.3%
supplement for increases in strength and muscle mass and 22.7% supplement for general
increases in performance (Goston & Correia, 2010). These studies demonstrate that
supplement use for physical performance and related factors are an important contributor
to the overall consumption of dietary supplements. Another study elaborated the rational
use behind supplement use in adolescent and college athletes. Young athletes now
understand that many famous athletes utilize these products to enhance performance and
break records and the notion that supplement use is necessary for success is growing
(Calfee & Fadale, 2006). It is becoming more commonly acceptable for athletes to
improve performance through ergogenic aids. Along with this, the pressure for success
in youths is rising to compete for scholarships as college tuitions continue to rise (Calfee
& Fadale, 2006).
Along with exercise performance and muscle/strength gain, there is also the
population that supplements with the goal of weight or fat loss. Though weight loss can
be related to an increase in performance in some sports requiring weight management,
many studies did not elaborate on the intention behind the weight loss. One study
conducted on the general population of adults discovered that an estimated 15.2% of
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adults (women 20.6%, men 9.7%) had ever used a weight-loss supplement (Blanck et al.,
2007). Along with the report, the authors also noted that as BMI increased, so did the
rate of supplement usage in adults (Blanck et al., 2007). Another study conducted on
college students revealed that 14.4% of participants reported using weight loss
supplements (Stasio et al., 2008). To add onto this theme, a multi-state survey conducted
in 1998 discovered that 7% of adults actively use over the counter (OTC) weight loss
supplements, and the greatest consumer population was young-obese women (Blanck et
al., 2001). Narrowing the score to the young adult population (ages 25-34); one study
conducting random digit-dialed telephone surveys completed in 2006 discovered that the
majority of this population (greater than 50%) engaged in weight loss supplement usage
(Pillitteri et al., 2008). From these studies it can be assumed that the overall amount of
younger weight loss supplement consumers is growing, and currently approximately 15%
of adults (with a significantly higher rate in women than men) are using weight loss
supplements. This can roughly amount to approximately one in every six or seven
individuals are consuming a dietary supplement of this category. In addition to women
and younger adults, this proportion seems to grow in other populations, such as those
exercising in gyms or participating in sports. A study performed on gym frequenters
reported that 21.7% of those surveyed took supplements for weight loss (Goston &
Correia, 2010). If accurate – this means that greater than one out of five physically active
individuals use weight loss supplements. With such a great amount of individuals
engaging in weight loss supplement practices; there is need to understand why these are
chosen over other measures of weight loss. One study identified in a table some of the
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reasons why OTC weight loss supplements are so popular, especially for those who are
overweight/obese. These reasons include: Social stigma of obesity, health benefits of
weight loss, desire for a “magic bullet” for weight loss, less demanding than accepted
lifestyle changes (such as exercise and diet), frustration with previous attempts at dieting
and/or exercise, easily available without a prescription, more easily accessed than a
professional consultation with a physician, nurse, or nutritionist, inflated advertising
claims, appeal of a “natural” remedy, and perception that natural equals safe (Saper et al.,
2004). From these reasons, it appears that consumers choose supplements due to the
convenience (in both usage and obtaining) and social aspects.
In addition to exercise performance and weight loss, many supplement consumers
also use for the reasons for general health, wellness, and prevention of disease. One
population often observed is college aged individuals. One study using division one
college athletes as participants showed that nearly half (43.5%) of the sample used
supplements for the reasons of maintaining health and wellness (Froiland et al., 2004).
Another study conducted on female division one athletes discovered that over half
(60.1%) consumed dietary supplements for good health (Herbold et al., 2004).
Common Types of Supplements
There are many different types of dietary supplements, but nearly all popular
choices can be sorted into a few distinct categories. The categories that will be described
in this Review of Literature includes Vitamin and Mineral Supplements, Protein and
Amino Acid Supplements, Ergogenic Aids, and Thermogenic Supplements.
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Vitamin and Mineral Supplements
One of the most recognizable categories under nutritional supplements is Vitamin
and Mineral Supplementation. Vitamin and mineral supplements typically provide either
a combination of vitamins and minerals (often referred as a multivitamin) or one specific
vitamin/mineral in one serving capsule/tablet. Vitamins and minerals (also referred to as
micronutrients) play important roles in energy generation, hemoglobin production,
maintaining bone health, supporting immune function, and serve as antioxidants
(Rodriguez et al., 2009). Though all the necessary vitamins and minerals can be obtained
through a healthy diet, many young athlete consumers regard these as medicine or
pharmaceuticals to obtain health benefits or a competitive edge (McDowall, 2007).
Along with this, these supplements may be popular in athletics involving energy/nutrient
restriction (gymnastics, wrestling, etc.) along with females attempting to maintain or lose
weight (Burns, 2001; McDowall, 2007). These populations may be at greater risk for
deficiencies, and the use of these supplements can be seen as an attempt to obtain
nutrients lacking from the restricted dietary intake.
The popularity of vitamin and mineral supplementation should be no surprise due
to the fact this category is the most commonly used supplement, especially in the young
athlete population (McDowall, 2007). This statement can be supported through one fairly
recent study involving supplement usage in division I college athletes which revealed that
73.3% of participants reported using vitamin and mineral supplementation (Burns, 2001).
In addition to the number of individuals who are consuming additional vitamins and/or
16
minerals, one study indicated that consumers used this form greater than five times per
week (Goston & Correia, 2010). Though it has been revealed that this is the most
common form of supplement used in both sexes, it was reported that females were
significantly more likely to use vitamin and mineral supplements than men (Froiland et
al., 2004). Females are also more likely to use certain single vitamin/mineral
supplements (such as calcium) (Goston & Correia, 2010).
For the most part, vitamin and mineral supplementation is safe and poses little
danger and a small threat to health. Rarely, these supplements may become a risk to
health if they are consumed excessively. This potential harm can develop from an
overconsumption of a specific nutrient (often times related to the consumption of a
supplement that contains only one nutrient), which may lead to toxicity (McDowall,
2007). In some cases, vitamin and mineral supplementation creates problems not directly
related to consumption. This category may serve as a gateway for consumers to progress
onto more supplements that may cause harm if consumed in reckless fashion (McDowall,
2007).
Protein and Amino Acid Supplements
Protein and Amino Acid supplementation is another popular nutritional
supplement category, and it has progressed into becoming a billion dollar industry
(Tipton & Wolfe, 2004). Put simply, amino acids are the organic molecules that serve as
basic constituents (or building blocks) for protein (Burns, 2001). Proteins are consumed
through the diet, and then are broken down into individual amino acids. These amino
17
acids are absorbed and then utilized to repair and replace damaged proteins, remodel
proteins within bones, ligaments, and tendons, maintain optimal function of metabolic
systems, support increases in lean mass, support optimal function of immune system, and
support reproduction of plasma proteins (Phillips et al., 2007). Though protein and
amino acids are typically sufficient through diet, they are also sold as supplements in the
form of meal replacement/protein bars, powders, pills, and calorie-replacement beverages
(McDowall, 2007). These types of supplements are towards the top of the list of most
commonly consumed supplements, especially for men (Froiland et al., 2004). Other
research has been reported that male athletes are significantly more likely to consume
protein and amino acid supplements than their female counterparts (Goston & Correia,
2010). In this study, supplements rich in protein and amino acids were consumed by
58% of male participants. Even in younger athletes, protein supplementation remains
fairly high. In one study, results displayed males consumed 38% more protein bars than
female counterparts, 15% more protein powders than female counterparts, and 8% more
amino acids than female counterparts (McDowall, 2007), These results definitively
provide support that these kind of supplements are often used, and may increase in the
future with the younger generation’s use.
One of the most debated topics related to protein and amino acids is associated
with the optimal protein intake. There is no simple statement or equation to determine
protein intake, and nitrogen balance is often used as an indicator (Tipton & Wolfe, 2004).
The general recommendation through the Recommended Dietary Allowances (RDA) for
sedentary individuals is 0.8 g of protein per kg of bodyweight (gP/kgBW) (Lemon,
18
1991). The need for protein in athletes increases and all sports may have different need.
The main determinant of protein requirement depends on their specific training regimen
and eating habits (Tipton & Wolfe, 2004). Endurance athletes generally are
recommended to consume 1.2-1.4 gP/kgBW, and Strength/Speed athletes are
recommended to consume 1.2-1.7 gP/kgBW (Lemon, 1991). These needs are more often
than not met by an athlete’s normal diet, and the individual does not require any
additional protein supplementation (Tipton & Wolfe, 2004). Despite these
recommendations, some athletes often over consume protein, sometimes to the point
where it is more than 2.5-3.0 gP/kgBW. Protein consumption at this point provides no
extra benefit to development and building of lean mass, and the excess protein is oxidized
(Tipton & Wolfe, 2004). For an athlete with the goal of an increase of muscle mass
(hypertrophy), it is recommended that they concentrate on an overall increase in calorie,
proper nutrient timing, and suitable source of protein rather than a drastic increase in
protein consumption (Tipton & Wolfe, 2004).
There are different times that an individual may consume a protein supplement.
Protein and amino acid supplementation is very popular post-exercise. Instead of eating
foods rich in protein and essential amino acids, some individuals may consume a
supplement instead. Again, protein supplementation here is not necessary. The amount
of protein that is recommended to be consumed (along with carbohydrate) is very
ambiguous; it can be differentiated by numerous factors such as timing of ingestion,
nutrients consumed along with protein, activity performed, and source of protein (Tipton
& Wolfe, 2004). Along with post-exercise, they may also be consumed during or intra-
19
exercise. One study reported that Branched Chain Amino Acid (BCAA) supplementation
during high intensity exercise may help minimize protein degradation, which in turn may
lead to gains in lean mass and inevitably, an increase in performance (Coombes and
McNaughton, 1995). Though an increase in fat-free body mass may be advantageous to
some, not all athletes find it to their benefit to become heavier (endurance athletes).
Despite this, one study demonstrated that a decline in BCAAs circulating in the blood can
contribute to fatigue in endurance events (Kreider, 1999). This report may propose the
use of BCAAs during endurance exercise to help improve performance.
Though it seems that protein an increase in protein consumption is relatively safe,
there may be some conflicting research to this assumption. Research in the past has
suggested that high protein intake has been related to an increase in kidney disease. This
may be true for those that have underlying kidney disease or complications, but in
healthy individuals there is no evidence for damage to kidneys with higher protein
intakes (Tipton & Wolfe, 2004). Along with kidney risk, there is also conflicting
research related to bone health and protein intake. Some reports suggest that excessive
protein intake results in an increase in calciuria (calcium excretion in urine) while others
have demonstrated an increase in indicators of bone health (Phillips et al., 2007). Despite
inconclusive research in these areas, excessive protein consumption can still pose a threat
to health. If an individual is at energy balance, protein intake that is too excessive (when
intake is past a point of 35-40% of total calorie intake) to the point where it is offsetting
consumption of other nutrients (carbohydrates and fats) may cause poor utilization and
compromise the benefits of other macronutrients (Phillips et al., 2007; Tipton & Wolfe,
20
2004). The recommendation to avoid this is to keep protein within the recommended
limits for the athletic type. The only time protein consumption should exceed 35% of
total calorie intake is in the case of calorie restriction (in which the recommendation may
remain the same, but total calorie intake decrease), in which maintenance of protein
intake in a hypocaloric state may help to prevent lean tissue losses (Phillips et al., 2007;
Tipton & Wolfe, 2004).
Ergogenic Aids
The term “Nutritional Ergogenic Aid” refers to a product (nutrients, metabolic byproducts, or food extracts) that enhances exercise/athletic performance (Benardot, 2012;
Rodriguez et al., 2009). This category of supplements is quite extensive, but very few
have been conclusively deducted to provide actually benefits to performance. The
Dietary Supplements and Health Education Act of 1994 allows supplement
manufacturers to make health claims –valid or not—on their products as long as they
include all of the supplements ingredients on the label of the product (Rodriguez et al.,
2009). Although manufacturers must report purity, strength, and identity of all the
ingredients in a product, they are not required to demonstrate safety or efficacy
(Rodriguez et al., 2009). Due to this, consumers must become very cautious while taking
performance enhancing agents for not only the fact that they may not provide benefit, but
also because they may be dangerous. This literature review will focus on the
scientifically proven and evidence backed substances.
21
Creatine. Creatine is now the most widely used ergogenic supplement among
athletes wanting to build lean tissue and improve exercise recovery (Rodriguez et al.,
2009). Creatine is a naturally occurring nitrogenous organic acid (composed of the
amino acids arginine, glycine, and methionine) that can be found in dietary sources such
as meat, poultry, and fish (Benardot, 2012; Burns, 2001). This compound is used to help
regenerate ATP from ADP in high-energy demanding situations (ATP-Creatine
Phosphate Energy system) (Burns, 2001, Juhn & Tarnopolsky, 1999; Rodriguez et al.,
2009). Though this substance is consumed in ample sources from athletes who do not
exclude animal product from dietary intake, it is most commonly sold as an additional
supplement in the form of Creatine Monohydrate (Burns, 2001). There are other forms of
creatine sold on the market, but creatine Monohydrate has the most research and
confirmed benefits associated with supplemental creatine.
Creatine supplementation’s effectiveness lies in its increased ability to assist in
regeneration of ATP for muscle contraction (Burns, 2001). In short, it can greatly
enhance performance for individuals participating in high-intensity, short duration
exercises (Juhn & Tarnopolsky, 1999). Examples of activities that can see benefit
include weight lifting, sprinting, high intensity cycling, and jumping. These exercises
require short, repeated bursts of energy that places the demands on the ATP-Creatine
Phosphate Energy system (Rodriguez et al., 2009). One study with the use of cycling
demonstrated that creatine supplementation is most ergogenic in repeated, 30 second
bouts of maximum output (Juhn & Tarnopolsky, 1999). Creatine supplementation may
be extremely useful for power athletes, but it will not assist in all sports. Research has
22
indicated that supplementation has no ergogenic benefit in submaximal or endurance
based exercise (Juhn & Tarnopolsky, 1999; Rodriguez et al., 2009). Put simply, sports
like long distance running, cycling, or swimming will see no need for using this
supplement.
For the most effective performance outcomes, creatine has specific dosing
protocols. There may be several protocols, but supplemental creatine is generally
recommended to be taking in phases. The first phase consists of a “loading” phase in
which an individual consumes five grams of the supplement, four times per day for the
first four to six days (Calfee & Fadale, 2006). The rationale behind this is to saturate
skeletal muscle tissue with the supplement. The following phase is a maintenance phase,
which consists of two grams of the supplement per day for three months to keep intramuscular concentration elevated (Calfee & Fadale, 2006). These recommendations may
change depending on different factors (examples include an athlete’s goals or
size/composition). Creatine may be of great use to many, but not all will observe benefits
with consumption. Approximately 30% of users will be “non-responders” who, in
theory, already naturally have maximal creatine stores in muscle tissue (Calfee & Fadale,
2006).
In the past, creatine supplementation has had a negative connotation for being a
dangerous or risky substance. Though creatine supplementation may have several side
effects, it is not a drug. The most prevalent side effect observed is weight gain. Clinical
studies investigating the dosages of 1.5-25 grams per day for three through 365 days has
23
reported an increase in weight in pre and post-operative, untrained and trained athletes
(Kreider, 1998). The increase in weight has been speculated to involve an increase in
water retention within muscle tissue. Along with weight gain, some consumers
experience nausea, cramping, and diarrhea (Rodriguez et al., 2009). Some studies have
potentially identified issues relating to kidney damage or dehydration, but there has been
no conclusive results (Rodriguez et al., 2009). Currently, it is not being monitored or
regulated by collegiate or international athletic organizations and has generally
recognized as safe, but it recommended to consult with a health care professional before
beginning use (Burns, 2001; Rodriguez et al., 2009).
Creatine supplementation dates back decades, but its use has only become popular
in the last twenty or so years. The massive increase of consumption began after a study
in 1992 that demonstrated that high doses oral creatine supplementation resulted in a 20%
increase of skeletal muscle creatine concentration (Burns 2001; Harris et al., 1992). A
fairly recent study conducted in division I athletes indicated that 31.4% of participants
surveyed have used creatine (Burns, 2001). In addition to serious athletes using this
supplement, a recent study revealed that creatine supplementation fell into the category of
most used supplements for individuals exercising in gyms (Goston & Correia, 2010).
Not only are the most elite athletes using creatine, but the recreational exercisers are also
included in the consumer population. Creatine supplementation is also more prevalent in
the male population. Recent research demonstrated that creatine is one of the most often
used supplements (along with protein and vitamin/mineral supplementation) in the
college male population (Froiland et al., 2004). Younger male athletes participate in this
24
supplementation; one study stated that creatine is 3% more likely to be taken by
adolescent males than females (McDowall, 2007).
Sports Beverages & Gels. Sports beverages and gels are commonly used as
convenient dietary supplements or ergogenic aids for busy athletes (Rodriguez et al.,
2009). Commercial sports beverages typically contain carbohydrate (usually in the form
of sucrose or fructose) as an energy source, fluid to prevent dehydration and
hyperthermia in hot environments, and electrolytes to replace losses through sweat
(Benardot, 2012; Lee et al., 2011). Notable products that fall into this category include
Gatorade and Powerade. This category of supplements does not include energy drinks or
thermogenesis induced diet/weight loss drinks. Opposed to sports drinks, gels contain
little to no fluid. These products are typically sold in single serve pouches and are
primarily composed of carbohydrate polymers (maltodextrin, fructose, dextrose) but also
many contain vitamins and minerals, BCAAs, and electrolytes (sometimes containing up
to 200-240mg Sodium per serving) (Benardot, 2012).
These products have been proven to be affective for a few simple reasons. The
first is that these supplements contain carbohydrate. Carbohydrate is the primary
substrate used to fuel high intensity exercise and higher intensity physical activity (Burns,
2001). When glycogen stores are depleted and there is no excess carbohydrate to fuel
exercise, there is a drastic decrease in exercise performance (Benardot, 2012; Lee et al.,
2011). This makes these products effective for athletes that are repeatedly working at
elevated performance levels with little or no break. If the training exceeds one hour,
25
athletes who can see benefit in this area include team sports like soccer, basketball,
football, hockey, and many more. High intensity athletics are not the only examples
where benefits can be seen. In endurance sports that operate at low intensities, there is
less carbohydrate used, and more of other substrates (fat, protein). Despite this,
carbohydrate is still a necessity for complete oxidation of other substrate (Benardot,
2012). The proportion and type of carbohydrate in the drink solution also plays an
impact on the effectiveness. When the concentration of carbohydrate in a solution
exceeds approximately 7%, there is a delay in gastric emptying time (Benardot, 2012).
Due to this, many manufacturers try to aim for a carbohydrate solution less than or equal
to 7% to allow for maximum absorption. The form of carbohydrate that they use is
important for absorption as well. Many products will use disaccharides or
polysaccharides in their products since glucose polymers are more easily digestible and
appear to be more effective at increasing exercise performance (Benardot, 2012). Along
with carbohydrate, sports drinks in particular contain both electrolytes and fluid. Since
both of these are essential during exercise and are lost in the process, it is assumed that
greater retention will lead to prolonged performance (Lee et al., 2011).
Sports drinks and gels are quite often used by athletes and non-athletes alike,
though many do not consider them to be dietary supplements (which potentially has
affected some research obtained in the field) (Burns, 2001; Froiland et al., 2004). In fact,
in the world of athletics it is quite rare to find an individual who has no used these
recovery products. One study conducted on division one reported that less than 6% of
participants answered never using recovery drinks, and that almost 73% of this
26
population continually use these products (Froiland et al., 2004). There appears to be no
significant difference in consumption between male and female athletes, as one recent
study stated that 73.4% of division one female athletes consumed sports beverages
(Herbold et al., 2004). As well as elite athletes, young athletes are also taking part in
consumption of these supplements. Results from another supplement study showed that
56% of adolescents used sports drinks (O’Dea, 2003).
Caffeine. Even though caffeine falls into the ergogenic supplement category, it is
also a Thermogenic Supplement. Caffeine is a compound in the methylxanthines
(stimulant) family that is found naturally in substances such as coffee, tea, and chocolate
(Benardot, 2012; Rodriguez et al., 2009). Caffeine’s popularity can be primarily noted to
its stimulant and thermogenic properties which makes it a primary ingredient in weight
loss products and energy drinks.
Caffeine’s ergogenic capacity lies in more than one single effect that it has on the
body. These performance enhancing results are related to increase metabolic rate (and
potentially weight loss), decrease body fat, provide glycogen sparing effects, and act as a
mental stimulant (Benardot, 2012; Krieder et al., 2010; Outlaw et al., 2013; Roberts et al.,
2009; Rodriguez et al., 2009).One result of caffeine supplementation lies in its ability to
alter energy sources that may be used in exercise. Caffeine increases the mobilization of
fatty acid from adipose tissue, making it available as an energy substrate during exercise;
this creates a glycogen sparing effect in lower intensity, endurance based exercise
(Benardot, 2012; Outlaw et al., 2013). This preservation of carbohydrate energy store
27
may help improve athletic performance primarily in long duration exercise such as
running, swimming, and cycling. Along with mobilizing stored fat, there are nervous
system benefits. Caffeine acts as a central nervous system stimulant. Caffeine
supplementation increases performance by increasing alertness, decreasing perceived
fatigue or sense of tiredness, and altering mood states (Benardot, 2012; Bruce et al.,
1986; Giesbrecht et al., 2010; Mitchell et al., 2011; Outlaw et al., 2013; Rodriguez et al.,
2009). The impacts as a nervous system agent can be beneficial to all different manners
of exercise and sport due to the fact that delaying fatigue and enhancing focus are two
important components for increased performance. There are several studies measuring
the impact on dosage. One study demonstrated that as little as 120mg of caffeine
improved alertness for three hours (Mitchell et al., 2011). On the higher end, another
study demonstrated improved alertness and decreased tiredness with different dosage
amounts between 250-500mg (Bruce et al., 1986). One current recommendation of
optimal Caffeine supplementation for athletes is to consume 3-9 grams of caffeine per
kilogram of bodyweight one hour per-exercise, though there have been benefits seen with
1-2 grams per kilogram of bodyweight in endurance athletics (Benardot, 2012). This
wide range of dosage can be dictated primarily by an individual’s caffeine
supplementation habits. If a consumer supplements frequently, it will not provide as
great of an ergogenic effect as an individual who sparingly uses caffeine (Benardot,
2012). For the greatest effect on performance, an athlete should abstain from use at least
seven days before competition (Benardot, 2012).
28
Due to caffeine’s powerful ergogenic properties, it has been monitored in the past
for both safety and ethical use during exercise. In 2004, the World Anti-Doping Agency
(WADA) has moved caffeine from the restricted list to the monitoring program giving
athletes the ability to use it in regulated sports (Rodriguez et al., 2009). Despite this
ruling, other organizations still restrict use. For example, the National Collegiate Athlete
Association (NCAA) restricts caffeine use. If tested-- an athlete must remain under a
caffeine concentration of 15 microgram per milliliter in urine to remain in compliance
and eligible for competition (Rodriguez et al., 2009). In the past caffeine has had a
negative reputation for causing hydration complications. New research has demonstrated
that caffeine (if used in moderation) will not cause dehydration or any electrolyte
imbalance, though it is recommended that it is not taken with any other drugs or alcohol
for safety (Armstrong, 2002; Armstrong et al., 2002, Rodriguez et al., 2009). Though it
is relatively safe to consume in moderation, it is not without any consequences. Potential
side effects of caffeine usage includes: headaches, anxiety, jitteriness, elevated heartrate,
gastrointestinal distress, and insomnia (Benardot, 2012; Graham et al., 2005; Rodriguez,
2009).
Since caffeine is found in a variety of different products, it is often difficult to
determine the exact consumption. Despite this, some studies have approximated caffeine
use in research. One past study revealed that 76% of participants (66% of the total
sample were college students) consume caffeinated products, and the total Caffeine levels
ranging from 100-500mg per day (Küçer, 2010). Another study discovered that only
5.3% of college freshman abstained from caffeine use in the last two weeks , and 85% of
29
these individuals are currently or previously participated in extra-curricular activities
(including sports) (McIlvain et al., 2011). This could potentially indicate that college
students may consume more caffeine than other populations and that many younger
athletes (high school and college) may be actively consuming caffeinated products. Two
of the major contributors to caffeine consumption in the college student population are
energy drinks and coffee. One study conducted in this population revealed that 51% of
students consumed at greater than one energy drink per month (Malinauskas et al., 2007).
There may also be a gender difference in caffeine consumption. Two studies have been
recently published surveying these differences. One of these research articles reported
that significantly more female college students (53%) consumed energy drinks than male
college students (42%) (Malinauskas et al., 2007). These results do not stop with energy
drinks, but also connect to other beverages. In reference to coffee consumption, the
incidence of coffee consumption in college students was 58.3% higher in females than
males (Gotia, 2013).
Thermogenic Supplements
Thermogenic (which literally breaks down into meaning generating heat)
Supplements target primarily individuals interested in weight loss primarily through
increasing basal metabolic rate and energy expenditure. These are advertised with the
goal of achieving a negative caloric balance, increasing weight loss, and improving body
composition through decreasing body fat mass (Kovacs & Mela, 2006). Thermogenic
supplements were made popular by sports such as bodybuilding, gymnastics, wrestling,
30
and other athletics that often require strict weight maintenance. Many of these
supplements have been extensively researched to quantify the effects on weight loss
physiology, and some of them have even been removed from the market by the Food and
Drug Administration (FDA) due to potential dangers associated with excessive or
incorrect consumption (Calfee & Fadale, 2006).
Weight loss supplements and Thermogenics are often categorized together despite
some substances not having any direct effect on metabolic rate. Though these substances
may not increase metabolism or assist in creating a negative caloric balance, they may
have some function in weight or body fat loss. Examples of these supplements include
garcinia cambogia and yohimbine. For the purpose of concentrating on thermogenic
supplements, these will not be elaborated on. For this portion of the literature review, the
supplements with a significant amount of research and that have demonstrated the more
dangerous thermogenic side effects will be addressed. These substances are caffeine
(previously addressed in Ergogenic Aids), ephedrine, and synephrine.
31
Ephedrine. Ephedrine (may also be referenced as ephedra) is one of the most
popular thermogenic supplements. Ephedrine is a stimulant with an amine chemical
structure similar to that of an amphetamine (Calfee & Fadale, 2006). Ephedrine is
derived from the Chinese herb Ephedra Sinica, or more popularly known as Ma Huang
(has also been referenced as “herbal ecstasy”) (Calfee & Fadale, 2006; Kovacs & Mela,
2006; Millman & Ross, 2003). Ephedrine can be found in numerous nutritional
supplement products that claim in increase athletic performance or assist in weight loss
through decreased appetite (Millman & Ross, 2003).
There are a few mechanisms that support the use of ephedrine by athletes.
Ephedrine traditionally has been used by athletes to provide quick energy and to aid in fat
loss, consequently improving speed and appearance (Calfee & Fadale, 2006). Nearly all
sports can see benefit in increased energy and better body composition so it should not be
surprising that it is a popular choice of supplements. It is especially advantageous in
enhancing short term athletic performance when an athlete is fatigued (Millman & Ross,
2003). These benefits are related to ephedrine’s alpha and beta adrenergic agonistic
effects. Ephedrine has the ability to enhance the release of norepinephrine and can
increase stimulation to the central nervous system (Calfee & Fadale, 2006). Ephedrine is
also a powerful weight loss supplement. One randomized, double blind, placebocontrolled study conducted in 1992 measured the effects of ephedrine (20mg), caffeine
(200mg), a combination of both (ephedra 20mg, caffeine 200mg), and a placebo on an
obese population. All of these individuals had controlled calorie intake to minimize
outside factors. The results indicated that the ephedrine/caffeine combination proved to
32
significantly improve weight loss in a 8-24 week period, and was more effective than any
other group (Astrup et al., 1992). In another similar study (with the same author and
completed in the same year) conducted on obese women it was reported that an ephedra
and caffeine combination in a restricted calorie environment resulted in greater weight
loss from fat and less loss in lean body mass than the placebo group (Astrup et al., 1992).
These two studies demonstrate how useful ephedrine can be for an athlete that aspires to
lose fat while preserving lean muscle tissue.
Ephedrine’s benefits are not without potential dangers. These dangers may be
exacerbated by combining ephedrine with caffeine or guarana, and these mixtures were
prohibited by the Food and Drug Administration (FDA) in the 1980s for posing a
significant risk to health (Calfee & Fadale, 2006). Ephedrine users have experienced
several side effects such as: dizziness, cerebral vascular accident, arrhythmia, insomnia,
myocardial infarction, seizure, psychosis, hypertension, and in the worst circumstances –
death (Astrup et al., 1992; Calfee & Fadale, 2006). Between these side effects and
incidents of supplement misuse (some of which resulted death), in 2004 the Food and
Drug Administration (FDA) banned ephedrine product sales in the U.S. (Calfee &
Fadale, 2006). In addition to the FDA’s ban of ephedrine, sports organizations do not
tolerate it’s use in athletes. The International Olympic Committee, NCAA, Major
League Baseball, National Basketball Association, and National Football League all have
banned the systemic use of ephedrine products (Calfee & Fadale, 2006).
33
Ephedrine supplementation is difficult to measure across populations because
some consumers are reluctant to report truthful responses with a substance with such a
negative reputation. Despite this challenge, many researchers has researched the athlete
population for high school and college aged athletes. One study conducted on college
hockey players reported that 38% of players have used ephedrine in the past, and 11% are
still currently supplementing (Bents et al., 2004). In another study performed on college
student-athletes, 6.3% of the participants surveyed use ephedrine products (Froiland et
al., 2004). From these results it may seem apparent that certain sports (especially those
involving weight management) may be more prone to using ephedrine products. In
addition to a college population supplementing with ephedrine, high school students are
also exposed to this. One study that supports this involved surveying 270 high school
athletes. Of the 270, 26% of females and 12% of males reported use of ephedrine
products (Kayton et al., 2002). This study may also suggest that females are more apt to
using ephedrine supplements.
34
Synephrine. Synephrine is the one of the most active substances contained in
Citrus Aurantium, a tree from Rutaceae family popularly named Bitter Orange, Seville
Orange, Sour Orange, Green Orange, Zhi Shi, and Kijitsu (Dwyer et al., 2005). In
addition to being found in the Citrus Aurantium tree, synephrine can also be found in
trace amounts in vertebrates as well as invertebrates (Rossato et al., 2011). Synephrine
exists in three distinct positional isomers, but only the p and m synephrine have been used
in weight-loss supplements (Rossato et al., 2011). synephrine is now cited as ‘the active
component’ of plants and dietary supplements used in weight loss due to synephrine’s
structural similarity to compounds such as adrenaline, noradrenaline, ephedrine,
amphetamine, and phenylpropanolamine (Dwyer et al., 2005; Rossato et al., 2011). This
compound and its related alkaloids became some of the most popular stimulants present
in modern weight-loss products after the FDA had eradicated the use of ephedrine as an
active ingredient in dietary supplements (Jitomir et al., 2008; Rossato et al., 2011).
The alleged thermogenic benefits associated with synephrine supplementation
comes from the supposed adrenergic stimulation with consistent use (Rossato et al.,
2011). Synephrine is an especially potent beta 3-AR agonist and may promote weight
loss (specifically fat) in humans through enhanced adipose tissue lipolysis (Jitomir et al.,
2008). This along with synephrine’s structurally similar form to ephedrine drive its use
in weight loss products. Despite these benefits, researchers are still inconclusive on
synephrine supplementation. There have been many contradicting studies conducted on
synephrine, and as a standalone supplement there is no strong evidence to support that it
is effective as a weight loss supplement (Rossato et al., 2011; Stasio et al., 2008). As a
35
single supplement no conclusions can be made, but there has been studies on the
combination of several thermogenics that support synephrine use. Recent research has
suggested that the combination of ingredients contained in thermogenic supplements
(caffeine, capsaicin, green tea extract, synephrine) work synergistically to prolong and
magnify the effects of a single dietary supplement alone (Diepvens et al., 2007,
Bergstrom et al., 2013; Jitomir et al., 2008; Rossato et al., 2011). Though most weight
loss products list ingredients in a proprietary blend and rarely list the specific amounts of
each supplement, most synephrine containing products typically possess between 1040mg of synephrine per serving (Dwyer et al., 2005).
Similar to ephedrine, synephrine also has health concerns with supplementation.
The growing use of synephrine has been accompanied by several reports of adverse side
effects. Examples of negative effects of synephrine supplementation includes cardiac
events such as: hypertension, tachyarrhythmia, variant angina, cardiac arrest, QT
prolongation, ventricular fibrillation, myocardial infarction, and in the worst
circumstances -- sudden death (Dwyer et al., 2005; Rossato et al., 2011). Due to this, it is
recommended that increased caution is recommended for Syneprhine consuming
individuals who have hypertension, cardiovascular disease, and narrow-angle glaucoma
(Dwyer et al., 2005). Athletes are still able to take this supplement in most organizations,
but it has not gone completely without attention. In 2009, synephrine was added to the
Monitoring Program in Competitions being sponsored by WADA (Rossato et al., 2009).
Synephrine supplementation habits are often difficult to determine because it is
rarely sold as a stand-alone supplement and there is little research in the field of this
36
specific supplement’s usage. Despite this, one study has conducted a survey in relation to
synephrine and reported that Americans who have previously consumed dietary
supplements, 73.8% used supposed ‘‘natural products’’ containing stimulants such as
caffeine, ephedrine, or synephrine (Blanck et al., 2007). With the associated dangers that
can arise from synephrine (or thermogenics in general) supplementation, this creates a
wide, empty gap that researchers should strive to fill on supplementation habits of at-risk
populations.
Less Dangerous Thermogenics. Aside from caffeine, ephedrine, and
synephrine, there are other popular thermogenics that are frequently used as dietary
supplements. Through thorough research, these weight loss agents have displayed
significantly less dangerous effects than ephedrine or synephrine, though at the same time
not as effective in manipulating metabolism. Other thermogenics with less severe side
effects and risks of use are green tea and yerba maté.
Green tea. Green tea (derived from the leaves of Camellia Sinensis) originated in
Southeast Asia, but is now cultivated in over 30 countries across the world (Graham,
1992). It is popularly consumed in either a liquid made from the tea leaves or in a
concentrated extract in capsule form. Unlike many other teas, green tea is brewed in such
a way so that the oxidation of the tea leaves is prevented, enabling a variety of health
benefits that cannot be obtained through other teas (Graham, 1992). Though the green
tea leaves are a natural source of caffeine, it also contains several catechins (antioxidants) with the most popular compound being Epigallocatechin gallate, or EGCG
(Dulloo et al., 1999). Several components of green tea are thought to affect weight and
37
fat loss through inhibition of lipases and stimulation of thermogenesis (Chantre & Lairon,
2002; Dulloo et al., 1999; Sharpe et al., 2006). Because of the natural caffeine content
found in green tea, it is a popular thermogenic supplement; though some studies believe
that green tea exclusively has weight loss properties. One example study comparing
green tea-caffeine (90mg green tea with 50mg caffeine) and caffeine (50mg)
interventions had concluded that green tea has thermogenic attributes and promotes fat
oxidation beyond that explained by its caffeine content (Dulloo et al., 1999). Along with
this, recent research has found that stimulation of thermogenesis and fat oxidation by the
green tea extract (no caffeine content) was not accompanied by an increase in heart rate
or cardiac alteration, making it a potential alternative for weight loss consumers who may
have hypertension or other cardiovascular disease (Chantre & Lairon, 2002).
Decaffeinated green tea research in human test participants revealed a significant increase
of energy expenditure, lowering of body weight, and tolerance with low risk of side
effects (Chantre & Lairon, 2002). Green tea has been deemed generally recognized as
safe unless used in excessive amounts (PDR for herbal medicines, 2007). The amount of
green tea in weight loss products ranges from 50-3,000 mg, though some products
contained different ratio of EGCG per catechins (Chantre & Lairon, 2002; Sharpe et al.,
2006). If caffeinated green tea is consumed, care should be exercised with individuals
who have a history of cardiovascular, renal, or thyroid conditions; side effects are those
similar to caffeine that include: anxiety, sleeplessness, heart palpitation, and other
symptoms of caffeine use (PDR for herbal medicines, 2007; Sharpe et al., 2006).
38
Yerba maté. Another supplement similar to green tea is yerba maté. Yerba maté
(Ilex paraguariensis) is an evergreen tree originally from the subtropical region of the
South America, present in the South of Brazil, North of Argentina, Paraguay and
Uruguay (Bastos et al., 2007; Pittler & Ernst, 2004). Beverages made from maté have
been consumed for hundreds of years as brews popularly known as chimarrão, tererê
(both from green dried mate leaves) and maté tea (roasted mate leaves) (Bastos et al.,
2007). Maté can be consumed in the form of a capsule supplement (often paired with
several other ingredients) as well as tea. The leaves (whether used for tea or supplement)
must undergo excessive processing (blanching, drying, and aging) before it is ready for
packaging (Heck & De Mejia, 2007). Unlike green tea leaves that are steamed of panfried during the blanching phase, mate leaves are flash-heated over open flames. Along
with this, green tea leaves are dried very quickly at a high temperature whereas mate
leaves are is dried very slowly often using wood smoke. The last large difference
between green tea and mate is the stem content. Green tea stems are usually removed
during the final grinding process while mate stems are have a high concentration in the
final product. (Graham, 1992; Heck & De Mejia, 2007). Maté products are rich in many
bioactive compounds (many similar to those in green tea) that serve as anti-oxidants,
diuretics, vasodilators, and stimulants; examples include such as caffeine, phenolic
compounds (mainly phenolic acids) and saponins (Bastos et al., 2007; Heck & De Mejia,
2007). The presence of these compounds make it popular for over the counter treatment
of arthritis, migraines, constipation, rheumatism, hemorrhoids, fatigue, retention of
liquid, hypertension, and for stomach and liver diseases (Bastos et al., 2007). Along with
39
these general uses, it is also quite popular for treatment of obesity and improving exercise
performance. Similar to green tea, it has some potential thermogenic and weight loss
properties. Yerba maté is a central nervous system stimulant and thermogenic; the
metabolic effects of maté seems to include the ability to maintain aerobic breakdown of
carbohydrates during exercise for an extended duration. This mechanism results in more
calories burned, thereby increasing cardiac efficiency and delaying the build-up of lactic
acid (Bastos et al., 2007). Along with this, one study investigating several plant-based
treatments on obesity found that although maté showed no significant increase in energy
expenditure, there was a drop in respiratory quotient observed, indicating a rise in the
proportion of fat oxidized (Martinet et al., 1999). Though as a stand-alone product,
results have been inconclusive in the past although it is often coupled with many other
weight loss ingredients for the best results (Andersen & Fogh, 2001; Martinet et al.,
1999; Saper et al., 2004). To support the theory, one study found that the combination of
mate with guarana and damiana significantly reduced gastric emptying time, reduced
time to perceived fullness, and induced significant weight loss in overweight patients
(Andersen & Fogh, 2001). With discretion, mate users typically observe no adverse side
effects (Pittler & Ernst, 2004). Aside from the effects associated with caffeine intake,
there is no immediate danger of any adverse side effects although the risk of variety of
cancers of the mouth, esophagus, bladder, kidneys, and lungs (Bastos et al., 2007; Heck
& De Mejia, 2007; Pittler & Ernst, 2004).
40
Gender Differences in Supplement Usage
Many researchers have discovered gender differences on supplementation habits.
Generally, it appears that more females consume dietary supplements than their male
counterparts. NHANES data collected between 2003-2006 reported that more female
individuals consume dietary supplements than males (53% in females vs. 44% in males)
(Bailey et al., 2010).
In general, it appears that most athletic males primarily use supplements related to
exercise performance. Many studies suggest that males tend to place more emphasis on
the athletic performance-enhancing factors of supplements whereas females tend to be
more concerned with the health benefits (Froiland et al., 2004; McDowall, 2007; Slater et
al., 2003; Sobal and Marquart, 1994). Studies conducted on college athletes and gym
exercisers reported that males are statistically significantly more likely to use
supplements like energy products, ginseng, DHEA, nicotine, energy drinks, calorie
replacement products, weight gainers, amino acids, and protein supplementation than
females (Froiland et al., 2004; Goston & Correia, 2010). These two studies also stated
that females are statistically significantly more likely to use vitamin and mineral
(especially Multivitamin products and Calcium) than males (Froiland et al., 2004; Goston
& Correia, 2010). Though it is unclear which sex consumes more supplements in
general, some studies have attempted to determine this in different populations. One
study conducted on the general adult population reported that the prevalence of weight
41
loss supplement use in the past year was 8.7% and was higher among women (11.3%)
than men (6.0%) (Blanck et al., 2007). This study may suggest that females tend to use
more thermogenic supplements, but another study conducted on gym exercisers showed
that men exercising in gyms consumed more supplements than women (44.6% versus
28.1%) (Goston & Correia, 2010). It is unclear on whether specific populations (athletes
for example) may affect gender consumption of supplements and this creates the
argument for more research may be performed in the future in this area of study.
Source of Supplement Information
The source of information regarding supplement habits may be just as important
as consumption habits. Athletes approach several different types of individuals for
supplement knowledge. A study conducted on division one college athletes revealed that
the participants gained their information from family (32.4%), fellow athletes (31.9%),
athletic trainers (30%), strength coaches (28%), dietitians (28.5%), friends (28.5%), and
coaches (28%) (Froiland et al., 2004). These results were supported by another study
conducted on female division one college athletes and concluded that this population
gained their information from Family (50.3%), Friends (24.6%), Physicians (18.7%),
coaches (10.5%), nutritionists (8.2%) (Herbold et al., 2004). In both cases, it appears that
athletes generally feel more comfortable approaching family and peers far more than
health care professionals. College athletes as well as other populations many be
obtaining nutrition knowledge from compromised sources. A study performed on people
exercising in gyms discovered more than half of participants (55%) consumed
supplements without seeking any professional guidance (Goston & Correia, 2010). Even
42
the general adult population may not be seeking answers from the appropriate sources.
One study on this population reported that only 30.2% of weight loss supplement users
consulted with their doctor about using these products (Blanck et al., 2007). The
assumptions that can be made from the displayed studies show that individuals are not
approaching dietitians (or any other health care professionals) before using potentially
dangerous dietary supplements.
CHAPTER III
METHODOLOGY
Purpose
The research was approved by the Kent State University Institutional Review
Board (IRB). The purpose of this study was to determine the thermogenic supplement
usage (which type of supplement is being used, servings per week, and reasons for use) in
male and female, athletes and non-athletes, college students enrolled at a Northeast Ohio
State University.
Hypotheses
There is a significant difference in thermogenic supplement usage between males
and females. There is a significant difference in thermogenic supplement usage between
the different exercise categories of participants.
Study Design
This study was a quantitative, non-experimental, post-test only. The independent
variables in this study are related to gender and athlete category. The dependent
variables are all factors related to supplement usage (which type of supplement is being
used, servings per week, and reasons for use).
43
44
Participants
A convenience sample of students enrolled at Kent State University was utilized.
The inclusion criteria for participants required enrollment at Kent State University (can
be part-time or full time and undergraduate or graduate) and the participant must be over
the age of 18. Prior to data collection, this study was approved by the Kent State
University IRB.
Questionnaire
The questionnaire began with an introduction which contained: (a) introduction of
the student researcher, (b) purpose of the study, (c) statement of confidentiality for
information collected, (d) an estimation for time of completion, (e) basic survey
directions, (f) statement of voluntary participation, (g) contact information of the primary
investigator for complaints or questions, and (h) an IRB approval statement. After this
introduction, the participants were provided with a consent statement which include
acknowledgement of the participant being over the age of 18 years, understanding of the
introduction, and consent for participation in the study. For this statement, the participant
could choose one of the two multiple: I agree or I do not agree. If the participant did not
agree, the survey automatically ended. The questionnaire introduction developed can be
seen in Appendix 1.
Following the introduction and consent statement, the survey contained three
sections: Part I: Demographics (including definition of terms associated for athlete
45
categories), Part II: Supplement Usage, and Part III: Sources of Information. The entire
questionnaire can be seen in Appendix 2.
Demographics
The Definition of terms listed in the demographics section provided a brief
description of thermogenic supplements and the different categories of athletes that an
individual may fall under (non-athlete, recreational athlete, competitive athlete, and
NCAA athlete). The demographics portion included seven questions (two open-ended
and four close-ended) to determine age, sex (male or female), enrollment status (part-time
or full-time), education level (graduate vs. undergraduate), major/area of study, athlete
category, and current exercise habits. The close ended questions included all except for
major/area of study and current exercise habits. The close ended questions were in a
multiple choice format where the participant can only choose one answer. The open
ended questions involved the participant entered their major/area of study and exercise
habits (related to minutes per day, days per week, type of exercise, and a description of
any competitions).
Supplement usage
The second part of the survey (Supplement usage) was more comprehensive than
the previous block. The participant answered questions that required them to indicate
usage for the following: caffeinated coffee, caffeinated tea, energy/sports drinks
(containing caffeine, green tea, ephedra, synephrine, yerba maté, capsaicin, or other
thermogenic/weight loss aids), nutritional supplements (containing caffeine, green tea,
46
ephedra, synephrine, yerba maté, capsaicin, or other thermogenic/weight loss aids),
caffeine/stimulant gum (containing caffeine, green tea, ephedra, synephrine, yerba maté,
capsaicin, or other thermogenic/weight loss aids), or energy gels (containing caffeine,
green tea, ephedra, synephrine, yerba maté, capsaicin, or other thermogenic/weight loss
aids). For each category, the participants were given the options for yes, no, or I don’t
know (only one response can be chosen). For every product that an individual indicates
“yes” for usage, they were asked four follow up questions detailing a specific product of
use (when applicable), frequency of usage, reason for usage, and an open ended question
that asked them to include any reasons for use not mentioned in the prior question.
The first follow up question related to specific product of use was open ended
with an optional response. This follow up question was used in all the thermogenic
substance categories except caffeinated coffee and caffeinated tea.
The frequency of usage question was in a multiple choice format (only one
response can be chosen). The frequency question also provided a sample serving size for
each category (caffeinated coffee/tea indicates one serving as 8 fluid ounces, the rest of
the product categories states one serving as indicated on the products label). The
frequency was in servings/week and the responses ranged from: 1-3, 4-6, 7-9, 10-12, or
12+ servings per week.
Following the frequency questions, the survey proceeded onto the reason for
usage questions for each category. The first reason for usage question included a five
point modified Likert-style scale (very untrue, untrue, neutral, true, and very true) for
47
each of the common motives for usage: factors related to exercise, cognitive
performance, general energy, weight loss or body composition changes, claimed health
benefits, taste/enjoyment, and convenience/habit. The second reason for usage question
was open ended, optional, and had the purpose of asking the participant if they had any
other reasons for usage aside from the previous question. This question was opened
ended and optional.
After each of the sub sections related to supplement usage was completed, the
participant proceeded onto the final part (Sources of nutritional supplement information).
This final part consisted of one question in a five point modified Likert-style scale format
(very unlikely to very likely). The participant chose one point of the scale for each of the
sources: family, friends, fellow athletes, coaches/athletic trainers/personal trainers,
doctors or physicians, dietitians or nutrition professionals, or media sources (TV
commercials, advertisements, magazines, etc.).
At maximum (if a student takes all the products listed above), the participant
answered 36 questions. At minimum (if a student takes none of the products listed
above), the participant answered 14 questions.
Procedure
A convenience sample was used for this study. The sample was obtained from
Kent State University’s Institutional Research. The sample consisted of 3,098
randomized student emails (including undergraduate and graduate students, and part-time
and full-time students). The email addresses were entered into Qualtrics version 2.4.
48
Qualtrics sent the survey questionnaire link to the sample in email format. This emailed
contained: (a) an introduction of the student researcher, (b) a brief description of the
survey topic and purpose, (c) a statement of confidentiality for the information obtained,
(d) an estimation for the time of completion, and (e) the URL link to the survey. The first
email was sent to participants on the morning of Monday, September 14, 2015. Two
email reminders that included the same contents as the first email were sent out each
Monday following the initial survey email (mornings of September 21st and September
28th). Survey responses were collected for three weeks and data was analyzed in October
2015.
Statistical Analysis
The data was entered into SPSS software version 22 IBM, New York for
statistical analysis by the Kent State University Research Bureau. Descriptive data was
analyzed to determine frequency, means, and standard deviations. A 2x3 Factorial
analysis of variance (ANOVA) was used for the analysis. There were two levels for
gender – male and female and three levels for athlete category – non-athlete, recreational
athlete, and competitive athlete. A Tukey post hoc analysis was used to analyze where
significant differences were between athlete groups. The significance level of this study
was set at p < 0.05.
Only one participant consumed energy gels and no participants consumed
stimulant gum. Due to the small amount of participants reporting use of stimulant gum
49
and energy gels, statistical analyses related to differences in gender/athlete group
frequency, therefore reasons for usage and could not but run for these two categories.
50
CHAPTER IV
JOURNAL ARTICLE
Introduction
Dietary substances have been used in past years for the purpose of increasing
health and wellness, exercise/athletic performance, lose body fat or manage weight,
increase muscle mass, prevent or treat medical problems, improve the immune system,
enhance alertness, and reduce stress (Gosten & Correia, 2010). The U.S. Food and Drug
Administration (FDA) defines a nutritional/dietary supplement as a product intended to
supplement the diet that typically contains one or more dietary ingredients (example:
multi-vitamins). Supplements can be taken in forms such as tablets, powders, capsules,
edible bars, and liquids (FDA, 2015).
A large portion of the population engages or has engaged in supplement usage,
especially college students. Data collected between the years of 2003-2006 indicated
49% of individuals over the age of one year consumed dietary supplements and 54% of
adults reported supplement use (Bailey et al., 2010). In relation to college students, one
study reported that 89% of collegiate athletes are taking or have previously taken
supplements (Froiland et al., 2004). Other studies have shown that supplementation is
typically self-prescribed and over half of physically active supplement users don’t consult
with a professional for advice (Goston & Correia, 2010). The intent of use for consumers
include: improved exercise performance, increased power/strength, gained muscle, lose
weight/fat, maintain health and wellness, and prevention of disease (Blanck et al., 2007;
50
51
Calfee & Fadale, 2006; Froiland et al., 2004; Goston & Correia, 2010; Stasio et al.,
2008). In addition to this, research has shown correlations involving gender. Many
studies suggest that males tend to place more emphasis on the athletic performanceenhancing factors of supplements whereas females tend to be more concerned with the
health benefits (Froiland et al., 2004; McDowall, 2007; Slater et al., 2003; Sobal and
Marquart, 1994).
One specific area of dietary supplements is thermogenic supplementation.
Thermogenics are often marketed with the purpose to assist consumers achieve a negative
caloric balance, increase weight loss, and improve body composition through increasing
the body’s metabolic rate (often resulting in an increase in body temperature or heat
release) (Kovacs & Mela, 2006). Side effects of some popular thermogenic supplement
ingredients include: hypertension, tachyarrhythmia, variant angina, cardiac arrest, QT
prolongation, ventricular fibrillation, myocardial infarction, dizziness, cerebral vascular
accident, arrhythmia, insomnia, myocardial infarction, seizure, psychosis, and death
(Astrup et al., 1992; Calfee & Fadale, 2006; Dwyer et al., 2005; Rossato et al., 2011).
Many thermogenics have been removed from the market by the FDA due to potential
dangerous side effects related to cardiac and mental stimulation issues associated with
excessive or incorrect consumption (Calfee & Fadale, 2006). Examples of substances
that are often included in the Thermogenic Supplement category include: caffeine,
synephrine, ephedra/ephedrine, green tea, garcinia cambogia, yohimbine, yerba maté, and
capsaicin.
52
The dangers of thermogenic supplement misuse combined with the amount of
individuals consuming supplements while not seeking professional guidance or obtaining
supplement advice from non-reputable sources is a problem that must be addressed to
ensure the health of college students, athlete or non-athlete alike. The risk of dangerous
supplement practices requires more research to determine specific habits of this
population.
The purpose of this study was to determine the thermogenic supplement usage
along with reason for use in male and female, athletes and non-athletes, college students
enrolled at a Northeast Ohio State University. There were two hypotheses for this study:
(a) there is a significant difference in thermogenic supplement usage between males and
females, (b) there is a significant difference in thermogenic supplement usage between
the different exercise categories of participants.
Methodology
This study was a quantitative, non-experimental, post-test only. The independent
variables in this study were gender (two levels) and athlete category (three levels). The
dependent variables were all factors related to supplement usage (which type of
supplement is being used, servings per week, and reasons for use).
53
Participants
A convenience sample of students enrolled at Kent State University was utilized.
The inclusion criteria for participants required enrollment at Kent State University (can
be part-time or full time and undergraduate or graduate) and the participant had to over
the age of 18.
Questionnaire
The questionnaire began with an introduction which contained: (a) introduction of
the student researcher, (b) purpose of the study, (c) statement of confidentiality for
information collected, (d) an estimation for time of completion, (e) basic survey
directions, (f) statement of voluntary participation, (g) contact information of the primary
investigator for complaints or questions, and (h) an IRB approval statement. After this
introduction, the participants were provided with a consent statement which included
acknowledgement of the participant being over the age of 18 years, understanding of the
introduction, and consent for participation in the study. If the participant did not agree,
the survey automatically ended. The questionnaire introduction developed can be seen in
Appendix 1.
Following the introduction, the survey contained three sections: Part I:
Demographics (including definition of terms associated for athlete categories), Part II:
Supplement Usage, and Part III: Sources of Information. The entire questionnaire can be
seen in Appendix 2.
54
Demographics
The Demographics portion included seven questions to determine age, sex,
enrollment status, education level, major/area of study, athlete category, and current
exercise habits.
Supplement usage
The second part of the survey (Supplement usage) was more comprehensive than
the previous block. The participant answered questions that required them to indicate
usage for the following: caffeinated coffee, caffeinated tea, energy/sports drinks
containing thermogenics, nutritional supplements containing thermogenics,
caffeine/stimulant gum containing thermogenics, or energy gels containing thermogenics.
For every product that an individual indicated “yes” for usage, they were asked follow up
questions detailing a specific product of use (when applicable), frequency of usage,
reason for usage, and an open ended question that asks them to include any reasons for
use not mentioned in the prior question.
The frequency of usage question was in a multiple choice format (only one
response can be chosen). The frequency question also provided a sample serving size for
each category. The frequency was in servings/week and the responses ranged from: 1-3,
4-6, 7-9, 10-12, or 12+ servings per week.
Following the frequency questions, the survey proceeded onto the reason for
usage questions for each category. The first reason for usage question included a five
point modified Likert-style scale (very untrue to very true) for each of the common
55
motives for usage: factors related to exercise, cognitive performance, general energy,
weight loss or body composition changes, claimed health benefits, taste/enjoyment, and
convenience/habit. The second reason for usage question had the purpose of asking the
participant if they had any other reasons for usage aside from the previous question.
After each of the sub sections related to supplement usage was completed, the
participant proceeded onto the final part (Sources of nutritional supplement information).
This final part consisted of one question in a five point modified Likert-style scale format
(very unlikely, unlikely, neutral, likely, and very likely). The participant chose one point
of the scale for each of the sources: family, friends, fellow athletes, coaches/athletic
trainers/personal trainers, doctors or physicians, dietitians or nutrition professionals, or
media sources (TV commercials, advertisements, magazines, etc.).
At maximum (if a student takes all the products listed above), the participant
answered 36 questions. At minimum (if a student takes none of the products listed
above), the participant answered 14 questions.
Procedure
A convenience sample was used for this study. The sample was obtained from
Kent State University’s Institutional Research. The sample consisted of 3,098
randomized student emails (including undergraduate and graduate students, and part-time
and full-time students). The email addresses were entered into Qualtrics version 2.4.
Qualtrics sent the survey questionnaire link to the sample in email format. This emailed
contained: (a) an introduction of the student researcher, (b) a brief description of the
56
survey topic and purpose, (c) a statement of confidentiality for the information obtained,
(d) an estimation for the time of completion, and (e) the URL link to the survey. The first
email was sent to participants on the morning of Monday, September 14, 2015. Two
email reminders that included the same contents as the first email were sent out each
Monday following the initial survey email (mornings of September 21st and September
28th). Survey responses were collected for three weeks and data was analyzed in October
2015.
Data Analysis
The data was entered into SPSS software version 22 IBM, New York for
statistical analysis by the Kent State University Research Bureau. Descriptive data was
analyzed to determine frequency, means, and standard deviations. A 2x3 Factorial
analysis of variance (ANOVA) was used for the analysis. There were two levels for
gender – male and female and three levels for athlete category – non-athlete, recreational
athlete, and competitive athlete. A Tukey post hoc analysis was used to analyze where
significant differences were between athlete groups. The significance level of this study
was set at p < 0.05.
Only one participant consumed energy gels and no participants consumed
stimulant gum. Due to the small amount of participants reporting use of stimulant gum
and energy gels, statistical analyses related to differences in gender/athlete group
frequency, therefore reasons for usage and could not but run for these two categories.
57
Results
Two hundred and twenty eight individuals started the survey out of 3,098 (7.4%).
Out of those participants, only data from 108 participants could be analyzed (3.5% of the
original sample). The demographics of these 108 participants can be observed in Table 1.
58
Table 1
Survey participant demographics of college students consuming thermogenic
supplements (N = 108)
Grouping
n
%
Male
Female
24
84
22.2
77.8
18-19
20-21
22-23
24-25
>25
0
1
1
26
80
0
0.9
0.9
24.1
74.1
Student type
Undergraduate
Graduate
71
37
65.7
34.3
Student enrollment
Part-time
Full-time
44
64
40.7
59.3
Athlete category
Non-athlete
Recreational athlete
Competitive athlete
NCAA athlete
49
54
5
0
45.4
50.0
4.6
0
Gender
Age
The usage of thermogenic supplements in college students can be seen in Table 2.
The most popular substances containing thermogenics were caffeinated coffee and
caffeinated tea. Fewer participants consumed energy/sports drinks and nutritional
supplements/diet pills.
59
Table 2
Types of thermogenic supplements used in college students reporting use
Product
N
Yes
No
Caffeinated coffee
108
75%
(n=81)
25%
(n=27)
Caffeinated tea
107
57%
(n=61)
43%
(n=46)
Energy/sports drinks
106
20.8%
(n=22)
79.2%
(n=84)
Nutritional supplement/diet
pills
106
12.3%
(n=13)
87.8%
(n=93)
Stimulant gum
106
0%
(n=0)
100%
(n=106)
Energy gels
106
0.9%
(n=1)
90.1%
(n=105)
The frequency of thermogenics usage can be seen inside of Table 3. Although
participant responses were distributed across all options, the majority of consumers
reported using at least seven servings per week of coffee. Caffeinated tea also had
responses distributed across all options although tea was not used as frequently as coffee.
The vast majority of energy/sports drinks consumers reported using less than four
servings per week. The majority of nutritional supplements/diet pill users reported using
between 4-9 servings per week. Only one participant reported using energy gels and this
participant reported using greater than 12 servings per week.
60
Table 3
Frequency of use of thermogenic supplements in college students consuming thermogenic
supplements 1
Product
f (n)
%
Caffeinated coffee* (n = 81)
1-3 servings/week
4-6 servings/week
7-9 servings/week
10-12 servings/week
12+ servings/week
9
18
21
9
23
11.3
22.5
26.3
11.3
28.8
Caffeinated tea* (n = 61)
1-3 servings/week
4-6 servings/week
7-9 servings/week
10-12 servings/week
12+ servings/week
35
12
8
2
3
58.3
20.0
13.3
3.3
5.0
Energy/sports drinks* (n = 22)
1-3 servings/week
4-6 servings/week
7-9 servings/week
10-12 servings/week
12+ servings/week
18
2
1
1
0
81.8
9.1
4.5
4.5
0
Nutritional supplements/diet pills* (n = 13)
1-3 servings/week
4-6 servings/week
7-9 servings/week
10-12 servings/week
12+ servings/week
2
5
5
1
0
15.4
38.5
38.5
7.7
0
Energy gels* (n = 1)
1-3 servings/week
0
0
4-6 servings/week
0
0
7-9 servings/week
0
0
10-12 servings/week
0
0
12+ servings/week
1
100
1
* Numbers reflect the participants that indicated consumption of each product.
61
Table 4 demonstrates gender differences in supplementation frequency. The only
significant value in this table is related to caffeinated tea usage between males and
females. This data suggests that men are significantly more likely to consume caffeinated
tea at a greater frequency than females (p > 0.05).
Table 4
Gender differences in supplementation frequency in college students consuming
thermogenic supplement usage 1,2
𝑋̅ ± SD
p-value
Caffeinated coffee
Male 1 (n = 19)
Female 1 (n = 61)
3.05 ± 1.51
3.3 ± 1.35
0.10
Caffeinated tea
Male 1 (n = 14)
Female 1 (n = 46)
1.79 ± 1.19
1.76 ± 1.12
0.01*
Energy/sports drinks
Male 1 (n = 7)
Female 1 (n = 15)
1.29 ± 0.76
1.33 ± 0.82
0.92
Usage/week
Nutritional supplements/diet pills
Male 1 (n = 2)
2.50 ± 0.71
0.31
Female 1 (n = 11)
2.36 ± 0.92
Note. The mean is calculated from data taken from a five-point modified Likert-style
scale. One equals 1-3 servings per week, two equals 4-6 servings per week, three equals
7-9 servings per week, four equals 10-12 servings per week, and five equals 12+ servings
per week.
1
Numbers reflect the participants that indicated consumption of each product.
2
A p-value with a * indicates significance with P < 0.05.
Gender differences in caffeinated coffee consumption is illustrated in Table 5.
The two reasons for use that show a significant difference are in general energy and
62
taste/enjoyment. This data suggest that females are more likely to consume coffee for the
reasons of general energy and taste/enjoyment than their male counterparts.
Table 5
Gender differences in reasons for caffeinated coffee usage for college students
consuming thermogenic supplements (N = 80) 1
Gender
𝑋̅ ± SD
p-value
Factors related to exercise
performance (strength, speed,
focus, stamina, etc.)
Male
Female
2.00 ± 1.33
2.37 ± 1.29
0.29
Cognitive performance
Male
Female
3.21 ± 1.44
3.53 ± 1.20
0.38
General energy
Male
Female
3.32 ± 1.38
4.11 ± 0.90
0.03*
Weight loss or body
composition changes
Male
Female
1.89 ± 0.99
2.07 ± 1.05
0.52
Claimed health benefits
Male
Female
2.22 ± 1.00
2.40 ± 1.12
0.53
Taste/enjoyment
Male
Female
3.79 ± 1.38
4.53 ± 0.82
0.04*
Convenience/habit
Male
Female
3.63 ± 1.17
3.97 ± 1.14
0.28
Reason for use
Note. The mean is calculated from data taken from a five point modified Likert-style
scale. One equals very untrue, two equals untrue, three equals neutral, four equals true,
and five equals very true.
1
A p-value with a * indicates significance.
63
Table 6 includes the data related to gender differences in reasons for usage for
caffeinated tea. The data in the table suggests that there is no significant difference (p >
0.05) in the reasons for use between males and females.
Table 6
Gender differences in reasons for caffeinated tea usage for college students consuming
thermogenic supplements (N = 61) 1
Gender
𝑋̅ ± SD
p-value
Factors related to exercise
performance (strength, speed,
focus, stamina, etc.)
Male
Female
2.21 ± 1.25
2.01 ± 1.19
0.79
Cognitive performance
Male
Female
2.64 ± 1.45
2.89 ± 1.32
0.57
General energy
Male
Female
2.79 ± 1.53
3.33 ± 1.21
0.24
Weight loss or body
composition changes
Male
Female
2.14 ± 1.00
2.40 ± 1.12
0.51
Claimed health benefits
Male
Female
2.43 ± 1.15
3.02 ± 1.50
0.16
Taste/enjoyment
Male
Female
4.36 ± 1.38
4.52 ± 0.55
0.61
Convenience/habit
Male
Female
3.71 ± 1.44
3.54 ± 1.44
0.70
Reason for use
Note. The mean is calculated from data taken from a five point modified Likert-style
scale. One equals very untrue, two equals untrue, three equals neutral, four equals true,
and five equals very true.
1
A p-value with a * indicates significance with P < 0.05.
64
Table 7 displays the data related to gender differences in reasons for usage for
sports/energy drinks. The data in the table suggests that there is no significant difference
in the reasons for use between males and females.
Table 7
Gender differences in reasons for energy/sports drink usage in college students
consuming thermogenic supplements (N = 22) 1
Gender
𝑋̅ ± SD
p-value
Factors related to exercise
performance (strength, speed,
focus, stamina, etc.)
Male
Female
2.14 ± 1.22
2.93 ± 1.49
0.21
Cognitive performance
Male
Female
3.57 ± 1.51
2.73 ± 1.28
0.23
General energy
Male
Female
4.00 ± 1.00
4.33 ± 0.74
0.45
Weight loss or body
composition changes
Male
Female
1.57 ± 1.13
2.36 ± 1.21
0.17
Claimed health benefits
Male
Female
1.57 ± 0.79
2.43 ± 1.28
0.08
Taste/enjoyment
Male
Female
3.14 ± 1.35
3.07 ± 1.44
0.91
Convenience/habit
Male
Female
3.00 ± 1.00
3.33 ± 1.29
0.52
Reason for use
Note. The mean is calculated from data taken from a five point modified Likert-style
scale. One equals very untrue, two equals untrue, three equals neutral, four equals true,
and five equals very true.
1
A p-value with a * indicates significance with P < 0.05.
65
Table 8 contains the data related to gender differences in reasons for usage for
nutritional supplements/diet pills. The data in the table suggests that there is no
significant difference in the reasons for use between males and females.
Table 8
Gender differences in reasons for nutritional supplements/diet pills usage in college
students consuming thermogenic supplements (N = 13) 1
Gender
𝑋̅ ± SD
p-value
Factors related to exercise
performance (strength, speed,
focus, stamina, etc.)
Male
Female
2.50 ± 2.12
3.64 ± 1.29
0.59
Cognitive performance
Male
Female
2.50 ± 2.12
3.36 ± 1.22
0.67
General energy
Male
Female
2.50 ± 2.12
4.00 ± 0.63
0.50
Weight loss or body
composition changes
Male
Female
1.50 ± 0.71
4.09 ± 0.94
0.06
Claimed health benefits
Male
Female
4.50 ± 0.71
4.00 ± 0.89
0.49
Taste/enjoyment
Male
Female
2.00 ± 1.41
2.36 ± 1.29
0.78
Convenience/habit
Male
Female
3.50 ± 0.71
2.45 ± 1.37
0.22
Reason for use
Note. The mean is calculated from data taken from a five point modified Likert-style
scale. One equals very untrue, two equals untrue, three equals neutral, four equals true,
and five equals very true.
1
A p-value with a * indicates significance with P < 0.05.
66
Table 9 includes the data obtained related to athlete category differences in
supplement frequency. This data demonstrates that there were significant differences in
supplement frequency for caffeinated tea as well as nutritional supplements/diet pills.
This data suggests that non-athletes consume caffeinated tea and nutritional
supplements/diet pills more frequently than any other group.
67
Table 9
Supplementation frequency differences between college athletes groups consuming
thermogenic supplements 1, 2, 3
Usage/week
𝑋̅ ± SD
p-value
Caffeinated coffee
Non-athlete 2 (n = 28)
Recreational athlete 2 (n = 49)
Competitive athlete 2 (n = 3)
3.46 ± 1.40
3.04 ± 1.35
4.33 ± 1.16
0.23
Caffeinated tea1
Non-athlete 2 (n = 23)
Recreational athlete 2 (n = 33)
Competitive athlete 2 (n = 4)
2.17 ± 1.34 a, b
1.52 ± 0.91 a
1.50 ± 1.00 b
0.01*
Energy/sports drinks
Non-athlete 2 (n = 4)
Recreational athlete 2 (n = 15)
Competitive athlete 2 (n = 3)
1.25 ± 0.50
1.40 ± 0.91
1.00 ± 0.00
0.79
Nutritional supplements/diet pills1
Non-athlete 2 (n = 4)
3.25 ± 0.50 a, b
2
0.04*
Recreational athlete (n = 6)
2.00 ± 0.89 a
2
b
Competitive athlete (n = 3)
2.00 ± 0.00
Note. The mean is calculated from data taken from a five-point modified Likert-style
scale. One equals 1-3 servings per week, two equals 4-6 servings per week, three equals
7-9 servings per week, four equals 10-12 servings per week, and five equals 12+ servings
per week.
1
Like letters demonstrate significant differences between groups.
2
Numbers reflect the participants that indicated consumption of each product.
3
A p-value with a * indicates significance with P < 0.05.
Table 10 contains the data for athlete category differences in caffeinated coffee
reasons for usage. It can be seen that there were no significant (p > 0.05) values
discovered.
68
Table 10
Differences in reasons for usage of caffeinated coffee between college student athlete
groups consuming thermogenic supplements (N = 80) 1
Category
𝑋̅ ± SD
p-value
Factors related to exercise
performance (strength, speed,
focus, stamina, etc.)
Non-athlete
Recreational athlete
Competitive athlete
2.50 ± 0.69
2.28 ± 0.91
3.33 ± 0.74
0.38
Cognitive performance
Non-athlete
Recreational athlete
Competitive athlete
3.39 ± 1.26
3.42 ± 1.27
4.67 ± 0.58
0.25
Non-athlete
Recreational athlete
Competitive athlete
4.11 ± 0.99
3.78 ± 1.12
4.67 ± 0.58
0.64
Weight loss or body
composition changes
Non-athlete
Recreational athlete
Competitive athlete
1.89 ± 0.99
2.04 ± 0.91
3.00 ± 2.00
0.20
Claimed health benefits
Non-athlete
Recreational athlete
Competitive athlete
2.18 ± 1.19
2.43 ± 0.99
3.00 ± 1.74
0.58
Non-athlete
Recreational athlete
Competitive athlete
4.50 ± 0.84
4.26 ± 1.23
4.33 ± 0.58
0.93
Non-athlete
Recreational athlete
Competitive athlete
4.04 ± 1.09
3.75 ± 1.19
4.67 ± 0.58
0.51
Reason for use
General energy
Taste/enjoyment
Convenience/habit
Note. The mean is calculated from data taken from a five point modified Likert-style
scale. One equals very untrue, two equals untrue, three equals neutral, four equals true,
and five equals very true.
1
A p-value with a * indicates significance with P < 0.05.
69
Table 11 displays the data for athlete category differences in reasons for usage for
caffeinated tea. The table displays data that there were no significant (p > 0.05)
differences between athlete groups for caffeinated tea reasons for usage.
70
Table 11
Differences in reasons for usage of caffeinated tea between college student athlete groups
consuming thermogenic supplements (N = 60) 1
Category
𝑋̅ ± SD
p-value
Factors related to exercise
performance (strength, speed,
focus, stamina, etc.)
Non-athlete
Recreational athlete
Competitive athlete
1.64 ± 090
2.28 ± 1.20
3.75 ± 0.96
0.17
Cognitive performance
Non-athlete
Recreational athlete
Competitive athlete
2.74 ± 1.36
2.76 ± 1.35
4.00 ± 0.82
0.21
Non-athlete
Recreational athlete
Competitive athlete
3.45 ± 1.14
2.94 ± 1.39
4.00 ± 0.82
0.21
Weight loss or body
composition changes
Non-athlete
Recreational athlete
Competitive athlete
2.09 ± 1.11
2.39 ± 1.32
3.25 ± 1.71
0.95
Claimed health benefits
Non-athlete
Recreational athlete
Competitive athlete
2.73 ± 1.39
2.88 ± 1.56
3.75 ± 0.96
0.71
Non-athlete
Recreational athlete
Competitive athlete
4.57 ± 0.51
4.45 ± 0.85
4.25 ± 0.96
0.25
Non-athlete
Recreational athlete
Competitive athlete
3.87 ± 1.39
3.33 ± 1.47
4.00 ± 1.16
0.43
Reason for use
General energy
Taste/enjoyment
Convenience/habit
Note. The mean is calculated from data taken from a five point modified Likert-style
scale. One equals very untrue, two equals untrue, three equals neutral, four equals true,
and five equals very true.
1
A p-value with a * indicates significance with P < 0.05.
71
Table 12 illustrates the data collected for athlete category differences in reasons
for usage for sports/energy drinks. This table displays that there were no significant (p >
0.05) differences between athlete categories for reasons for usage of sports/energy drink
usage.
72
Table 12
Differences in reasons for usage of sports/energy drinks between college student athlete
groups consuming thermogenic supplements (N = 22) 1
Category
𝑋̅ ± SD
p-value
Factors related to exercise
performance (strength, speed,
focus, stamina, etc.)
Non-athlete
Recreational athlete
Competitive athlete
2.50 ± 1.73
2.87 ± 1.46
2.00 ± 1.00
0.87
Cognitive performance
Non-athlete
Recreational athlete
Competitive athlete
2.50 ± 1.73
3.27 ± 1.28
2.33 ± 1.53
0.83
Non-athlete
Recreational athlete
Competitive athlete
4.50 ± 0.58
4.07 ± 0.88
4.67 ± 0.58
0.73
Weight loss or body
composition changes
Non-athlete
Recreational athlete
Competitive athlete
2.25 ± 1.50
2.14 ± 1.23
1.67 ± 1.56
0.79
Claimed health benefits
Non-athlete
Recreational athlete
Competitive athlete
2.25 ± 1.50
2.14 ± 1.23
2.00 ± 1.00
0.94
Non-athlete
Recreational athlete
Competitive athlete
2.50 ± 1.73
3.33 ± 1.29
2.67 ± 1.53
0.69
Non-athlete
Recreational athlete
Competitive athlete
2.50 ± 1.73
3.27 ± 1.03
4.00 ± 1.00
0.19
Reason for use
General energy
Taste/enjoyment
Convenience/habit
Note. The mean is calculated from data taken from a five point modified Likert-style
scale. One equals very untrue, two equals untrue, three equals neutral, four equals true,
and five equals very true.
1
A p-value with a * indicates significance with P < 0.05.
73
Table 13 contains the data related to athlete category differences in reasons for
nutrition supplement/diet pill usage. This chart displays that there was significance in
reasons for usage for general energy and taste and enjoyment (p > 0.05). This data
suggests that non-athletes (followed by recreational athletes) are less likely to supplement
for the reasons of taste and enjoyment than competitive athletes.
74
Table 13
Differences in reasons for usage of nutritional supplements/diet pills between college
student athlete groups consuming thermogenic supplements (N = 13) 1, 2, 3
Category
𝑋̅ ± SD
p-value
Factors related to exercise
performance (strength, speed,
focus, stamina, etc.)
Non-athlete
Recreational athlete
Competitive athlete
3.25 ± 1.71
3.33 ± 1.63
4.00 ± 0.00
0.37
Cognitive performance
Non-athlete
Recreational athlete
Competitive athlete
3.25 ± 1.71
2.83 ± 1.17
4.00 ± 1.00
0.26
Non-athlete
Recreational athlete
Competitive athlete
4.00 ± 0.00
3.33 ± 1.37
4.33 ± 0.58
0.02*
Weight loss or body
composition changes
Non-athlete
Recreational athlete
Competitive athlete
4.75 ± 0.50
3.17 ± 1.33
3.33 ± 1.53
0.17
Claimed health benefits
Non-athlete
Recreational athlete
Competitive athlete
4.50 ± 0.58
3.67 ± 1.03
4.33 ± 0.58
0.56
Non-athlete
Recreational athlete
Competitive athlete
1.50 ± 1.00 a
2.00 ± 0.63 a
4.00 ± 1.00 a
0.01*
Non-athlete
Recreational athlete
Competitive athlete
1.75 ± 1.50
2.50 ± 0.84
4.00 ± 1.00
0.10
Reason for use
General energy3
Taste/enjoyment2
Convenience/habit
Note. The mean is calculated from data taken from a five point modified Likert-style
scale. One equals very untrue, two equals untrue, three equals neutral, four equals true,
and five equals very true.
1
A p-value with a * indicates significance with P < 0.05.
2
Like letters demonstrate significant differences between groups.
3
Post Hoc analysis pairwise comparison did not demonstrate difference between groups.
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Discussion
The purpose of this study was to determine the thermogenic supplement usage
and reason for use in male and female, athletes and non-athletes, college students
enrolled at a Northeast Ohio State University. There are two hypotheses for this study.
The first is that there is a significant difference in thermogenic usage between males and
females. The second is that there is a significant difference between the different
exercise categories of participants. The results of this study dictated that both of these
hypotheses were partially accepted.
Subject Characteristics
Women were over represented in the sample used in this study with less than one
fourth of participants responding being male. According to the Kent State University
facts and figures webpage, the undergraduate student body was made up of
approximately 41% males and 59% female in 2014 (n.d.). Although the study’s
participants did not perfectly represent the entire student population, this may be one
variable that influenced a greater female response.
Furthermore, the majority of participants were over the age of 25 with less than
one fourth of participants being under 25. According to Kent State University college
portrait site, the average age of undergraduate students was 22 years old in 2014 (n.d.).
Although some participants from this study were graduate students (typically older than
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undergraduate students), ideally there should have more than two participants
representing the population of students under the age of 24 at Kent State University.
In reference to athlete category demographics, nearly all participants were either a
non-athlete or recreational athlete. Less than five percent of participants were
competitive athletes and not a single participant was a NCAA athlete. Although there is
little research on the amount of non-NCAA competitive athletes in colleges, this may
have been an accurate representation of NCAA athletes in this study. There are
approximately 425 NCAA athletes out of over 29,000 undergraduate students at Kent
State (Kent State Sports, n.d.). This is roughly 1.47% of the total student body. With 71
undergraduate participants, statistically there would have been only one participant.
These statistics validate the lack of response that was obtained from this population.
Gender
This study discovered that there were significant differences in gender
thermogenic usage in a few key areas. The first significant difference was in caffeinated
tea usage. The data suggests that males are more likely to consume servings of
caffeinated tea more frequently than females. This challenges the reports of another
study on college age students that indicated that females significantly consume more tea
than male counterparts (Demura et al., 2013). Despite a significance generating, there
was a very small difference between the gender means and it is deemed biologically
insignificant and was probably due to a mathematically anomaly. This theoretical
insignificance can be supported by the NHANES data collected during 2007-2008 that
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reported men and women over the age of 20 consumed equivalent amounts of tea
(LaComb et al., 2011).
Females were significantly more likely to consume caffeinated coffee for the
reasons of general energy and taste/enjoyment than males. Although both groups ranked
taste/enjoyment as the highest reason for use, females were statistically proven to use
more for this reason than males. These results contradicted a past study conducted on
college aged students that suggested that females are no more likely to consume coffee
for these reasons (Demura et al., 2013).
Although there were many gender differences, there were also other interesting
points observed in the data. One similarity shared between males and females was the
lower frequency of use in energy/sports drinks compared to other products. These results
can be supported by the FDA’s report analyzing caffeine consumption between the years
of 2003-2008. This report stated that the mean daily intake of energy drinks was several
times lower than the consumption of other caffeine containing beverages (coffee, tea, and
carbonated soft drinks) for adults over 22 years old (Somogyi, 2012). In addition to this
low frequency of use, both groups ranked the most likely reason for use as general energy
and the least likely reason for use as claimed health benefits (the rest of the reasons
remained fairly neutral). These results are supported by a past study conducted on
college students on energy drink usage. This study reported that: consumers use between
1-4 drinks per month, 65% of consumers use for the reason of energy, and 67% of
consumers use for the reason of insufficient sleep (Malinaukas et al., 2007). This
78
indicates that students infrequently use these products and primarily use for energy
unrelated to exercise (perhaps related to lack of sleep or general fatigue).
The highest frequency beverage for both genders was determined to be coffee.
This goes along with the FDA caffeine consumption report which indicated that coffee
was the second most consumed caffeinated beverage (only second to carbonated soft
drinks) for adults who over 22 years old (Somogyi, 2012). It was also discovered that
males and females alike are unlikely to use caffeinated coffee and tea for weight loss or
body composition and more for the reasons of taste/enjoyment and convenience/habit.
These results are supported by two studies in a student aged population that identified
taste as one of the most important factors of coffee/tea usage and one study conducted on
freshman psychology students that indicated that time of day and habit were highly
scored reasons (Demura et al., 2013; Graham, 1988; Olsen, 2013). The combination of
past research and this study shows that these products are most likely an established
dietary practice used for gratification over other reasons.
Although the results of the study partially validate the hypothesis related to
gender differences, it was not in the area that was anticipated. In general, the results did
not align with the past literature on gender difference of usage of supplements (although
this was more specific to thermogenics). One study conducted on the general adult
population reported that weight loss supplement usage was significantly higher in
females than males (Blanck et al., 2007). The results from the nutritional supplement/diet
pill usage section did not indicate any significance. The data indicated that both genders
79
scored claimed health benefits higher than any other reason. Past studies suggest that
males tend to place more emphasis on the athletic performance-enhancing factors of
supplements whereas females tend to be more concerned with the health benefits
(Froiland et al., 2004; Herbold et al., 2004; McDowall, 2007; Slater et al., 2003; Sobal
and Marquart, 1994). In fact (although no significance was found), females had a higher
mean than males in reasons for use related to exercise performance and males had a
higher mean than females in reasons for use related to claimed health benefits.
Athlete Category
There were also significant differences found in athlete categories. These include
category differences in supplement frequency of caffeinated tea and nutritional
supplements and reasons for use of nutritional supplements/diet pills related to general
energy and taste/enjoyment.
The first difference is related to supplement frequency between groups. The data
suggested that non-athletes consume caffeinated tea and nutritional supplements/diet pills
more frequently than any other group. The rationale behind non-athletes having higher
frequency of nutritional products/diet pills consumption can be related to weight
management. Some non-athletes can be safely assumed to have a higher prevalence of
overweight/obesity than the other groups since they lead a sedentary lifestyle. Two
studies conducted by the same author indicated that as BMI increased, so did the rate of
weight loss supplement usage in adults and that the young obese were the greatest
consumer of over the counter weight loss supplements (Blanck et al., 2007; Blanck et al.,
80
2011). This non-athlete population may be looking for a quick and easy solution for
weight loss opposed to the use of exercise as a tool. These statements can be validated by
past research demonstrating the overweight/obese consumers use these products because:
(a) they desire for a “magic bullet” for weight loss, (b) they are less demanding than
accepted lifestyle changes (such as exercise and diet), (c) consumers are frustration with
previous attempts at dieting and/or exercise, and (d) products are easily available without
a prescription (Saper et al., 2004).
The second difference was related to reasons of usage for nutritional
supplements/diet pills. The data analysis indicated that there was a significance
(although there was no interaction significance generated between groups) for the reasons
of general energy. Despite this, it can be seen that the means for non-athletes and
competitive athletes were higher than recreational athletes for the reason of general
energy. Although there are past studies that demonstrated general energy as one of the
most fundamental reasons of supplementation for elite athletes, college athletes, and
general population alike, there has been no research comparing each (Froiland et al.,
2004; McDowall, 2007; Slater et al., 2003). There may be one theory behind this result.
This could be associated with the non-athlete sedentary lifestyle and competitive athlete
high volume training lifestyle causing feelings of decreased energy. Exercise in general
provides feelings of improved energy although over-exercising can lead to chronic
fatigue (Brooks & Carter, 2013; Schmidt, 2012). This theory is logical because the group
with the lowest mean was recreational athletes with the happy medium of doing enough
81
exercise to provide feelings of energy (unlike non-athletes) while not over-training and
causing excessive fatigue like competitive athletes.
For taste and enjoyment, there were significance differences found between nonathletes and competitive athletes and recreational athletes and competitive athletes. This
data suggests that competitive athletes are more likely to use nutritional supplements/diet
pills for taste and enjoyment and convenience/habit than the other groups. In fact,
competitive athletes consistently scored convenience/habit higher than all groups across
all product categories. There is very little research that measured taste/enjoyment and
convenience/habit as reasons for supplement usage. Although there is a gap of research
in this area, one study demonstrated that over 75% of individuals who exercise in the
gyms reported that they practice healthy behaviors because it was a habit (Gosten &
Correia, 2010). This may be relatable to supplement usage as well. Since competitive
athletes scored claimed health benefits so highly for nutritional supplement/diet pill
usage, it can be assumed that they identify this as a healthy behavior. Competitive
athletes may practice supplementation as a habit. If competitive athletes are in the habit
of consuming these products daily, perhaps it becomes a tradition of sorts and gives a
sense of indulgence depending on the form of these supplements (examples being
flavored pre-exercise drinks or gummy/chewable supplements).
Along with these differences, there were also numerous similarities. First, all
athletes groups indicated they use energy/sports drinks less frequently than all other
products and that they consume caffeinated coffee more than all other products. Again,
82
this data is supported by the FDA caffeine consumption report indicating coffee was
consumed in several times greater quantity than energy drinks (Somogyi, 2012). Along
with caffeinated coffee being used the most, all groups also indicated they use more for
the reasons of taste/enjoyment, general energy, and convenience/habit. Caffeinated tea
was comparable to coffee with the highest reasons for use in taste/enjoyment and
convenience/habit. Sports/energy drinks were also most likely used for general energy
across all groups. Similarly to gender differences with all of these products, the use of
caffeinated coffee and tea is more of a daily tradition for both gratification whereas
sports/energy drinks are infrequently used for only for circumstances where energy is
needed (Demura et al., 2013; Graham, 1988; Malinaukas et al., 2007; Olsen, 2013).
The last similarity was related to the reasons for usage of thermogenic
supplements/diet pills. The highest scored reason across all groups for reasons for use
was discovered to be claimed health benefits of supplements. This is not surprising since
past research on college athletes has indicated that maintaining good health is the main
reason for nutritional supplementation for around half of students (Froiland et al., 2004;
Herbold et al., 2004). Although not all of these supplements are necessarily healthy,
college consumers may be deceived by the fact that the term natural doesn’t necessarily
indicate safe or beneficial to health (Saper et al., 2004).
Strengths
The questionnaire used in this study was very thorough in collecting data related
to thermogenic supplements and athlete category. It included multiple product categories
83
that may contain thermogenics to make it more accurate on the participant consumption.
This helped to determine which form of thermogenic supplementation was most popular.
In addition to this, some categories included an open ended question that required
participants to list which products they consumed, also improving the accuracy of data
collected. It also had detailed questions detailing frequency of usage per week and a
modified Likert-style scale detailing reasons for use. All of this additional data collected
gives a more in depth insight of characteristics of thermogenic supplement users and
usage in general.
Limitations
This study has a few notable limitations. During the first day of the survey
distribution, there was a filter placed that sent participants to the end of the survey if they
were over the age of 25. This filter was removed within six hours of the initial
distribution. During that time, over 100 participants over the age of 25 were unable to
complete the rest of the survey.
Along with this, there was a very poor response rate. Only 228 individuals started
the survey out of 3,098 (7.4%). Out of those participants, only data from 108 participants
could be analyzed (3.5% of the original sample). From these 108 participants, there were
only five participants who considered themselves competitive athletes and there were no
participants who were NCAA athletes. Because of the poor volume of participants in
these categories, the data taken may be less reliable. Also, the majority of participants in
this study were female (n = 84, 77.8%). This further limits the amount of male related
84
data in each of the athlete categories. When looking at these categories as a whole, it will
not properly represent an even balance of male and female data. This further
compromises the validity of data.
In addition to the lack of participants in these athlete categories, there was also
poor diversity in the age of participants. There were no participants under the age of 20,
3 participants between the ages of 20-21, and two participants between the ages of 22-23.
The remainder of these participants were aged 24 years or older. This shows that there
was a large population of college students (typically undergraduate aged students from
18-22/23 years old) with little-to-no data available.
Recommendations for Future Research
Based on the results of this study, there are several recommendations for future
research. First, an investigator could not place an age restriction on the survey similar to
the one that was used in this study. This would not exclude any data from the statistical
analysis. Another limitation of this study was the poor response rate in general
(especially in the <25 years of age population). To improve the response rate of these
applicants an investigator could use incentives that would appeal to a younger audience.
One example could involve a raffle of several gift cards at the end of the survey period
for participants. Along with these recommendations, perhaps a larger listserv could be
used. This would help to increase the accuracy of data as well as potentially obtain data
from some of the groups that weren’t represented in this study. If future studies require
85
more specific data in populations that weren’t well represented, another sampling
technique can be used to increase specificity of the participants.
Applications
The results of this study indicated that a large percentage of the participants
engaged in thermogenic usage. The two most commonly consumed thermogenics were
caffeinated coffee and caffeinated tea. These were used primarily for taste/enjoyment
and convenience/habit. The consumers of these products are using for the gratification,
not the thermogenic qualities. Due to this, they are less likely to abuse these drinks for
weight management or exercise performance. This is useful for practicing dietitians to
know because most patients consuming exclusively coffee and tea may be at less risk of
developing dangerous weight loss or exercise behaviors (McDowall, 2007). These
products, if consumed appropriately and in moderation, offer very little risk for
dangerous health consequences.
The real danger is when these products are consumed inappropriately and in
conjunction with other thermogenics. The FDA reports that in reference to caffeine, it is
generally recognized as safe for healthy adults with no medical issues to consume up to
400 milligrams per day (FDA, 2013). The estimated per capita daily caffeine intake for
adults over 22 years old is greater than 300 milligrams – keep in mind this is the average
between consumers and non-consumers of these products (Somogyi, 2012). Individuals
consuming one or two servings of caffeinated beverages and caffeine from food sources
are at little risk of reaching this limit. If used inappropriately, consumers can easily
86
exceed 400 milligrams if they regularly drink one serving of coffee, tea, and energy drink
per day (not including caffeine in nutritional supplements or soft drinks) (FDA, 2013;
Somogyi, 2012). The real danger is if consumers regularly combine multiple caffeine
beverages and other thermogenic supplements. If a patient is using multiple products at a
high frequency, they are at risk of developing mental stimulation or cardiac issues that
may result in permanent health consequences or even death (Astrup et al., 1992; Calfee &
Fadale, 2006; Dwyer et al., 2005; Rossato et al., 2011).
This data supports the claim that dietitians should develop and regularly
implement a screening tool for thermogenic usage in patients. Especially in the
adolescents and college students who are identified to be at higher risk of excessive
caffeine consumption from beverages (Somogyi, 2012). If an individual is positively
screened for risk of thermogenic/stimulant overconsumption, it becomes the dietitian’s
responsibility to educate users on appropriate consumption, quantity, and risks of over
usage. This scenario identifies one instance where it would be advantageous for
professionals to develop educational materials that are readily available when working
with these at-risk populations.
It was also discovered that all individuals scored claimed health benefits very
highly for the use of nutritional supplements/diet pills. This indicates that most
individuals assume that thermognic nutritional supplements are considered healthy. In
this circumstance, it is important for dietitians to be knowledgeable about ingredients in
nutritional supplements and the regulation regarding them. Since the FDA and FTC have
87
little power over the claims advertised by supplement manufacturers, consumers can be
easily deceived into the belief that these products offer health benefits. It is the
responsibility of dietitians to educate consumers that not all nutritional supplements offer
health benefits and that natural doesn’t always necessarily mean safe or effective.
In addition to this, this data may be an accurate representation of thermogenic
supplement usage in a female population. More specifically, this data can be analyzed to
report the results of females of 25 years of age. The results of this study discovered that
the highest score reason for use of nutritional supplements/diet pills containing
thermogenics was for weight loss and body composition changes. These findings would
be valuable for dietitians who specialize in weight management practice (especially while
working with sedentary and/or overweight/obese patients) where weight loss/thermogenic
product usage is more popular (Blanck et al., 2007; Blanck et al., 2011). Dietitians in this
area or similar practice should make it a priority to screen and become familiar with the
usage and reasons for usage of thermogenics. Understanding how and why these
products are used give nutrition professionals a deeper insight in providing
recommendations for safe usage in clients. Using developed educational materials,
different counseling techniques, and appropriate referrals to other health care providers
(more specialized dietitians, psychiatrists, psychologists, medical doctors, counselors,
etc.) can help to protect supplement users from misuse or progressing onto more
dangerous supplementation or weight loss practices.
88
Conclusion
In summary, this study identified a few key differences in thermogenics
supplementation associated with both gender and athlete category. The hypotheses were
partially supported, although not in the expected areas. The gender significant
differences were associated with men consuming caffeinated tea more frequently than
females, and females consuming caffeinated coffee more for the reasons of general
energy and taste and enjoyment than males. This data contradicts past research related to
general supplement usage related to gender although past literature has not been
specifically targeted towards thermogenic supplementation. These studies suggest that
males tend to place more emphasis on the athletic performance-enhancing factors of
supplements whereas females tend to be more concerned with the health benefits
(Froiland et al., 2004; McDowall, 2007; Slater et al., 2003; Sobal and Marquart, 1994).
Also, past studies support that females are more likely to use weight loss supplements
than males (Blanck et al., 2007). This study failed to report data that supports these
claims. The significant athlete category differences in supplement frequency of
caffeinated tea and nutritional supplements and reasons for use of nutritional
supplements/diet pills related to general energy and taste/enjoyment. Competitive
athletes were found to use nutritional supplements mores for the reasons of taste and
enjoyment than non-athletes and recreational athletes. Due to the large differences in the
number of participants in each athlete category and gender, further research is necessary
to support or renounce the data that was collected in this study.
APPENDICES
APPENDIX A.
CONSENT FORM
Dear Kent State Student:
My name is Luc LaBonte and I am currently a graduate student in Nutrition. The purpose of this
study is to obtain information regarding Thermogenics Usage in College Students. The survey's
purpose is to determine if gender or exercise habits and classification (non-athletes, recreational
athletes, competitive athletes, NCAA athletes) influence supplement usage. Your answers are
confidential and will be reported only as grouped data.
The survey takes approximately 10 minutes to complete. Please answer the following questions
to the best of your ability. For the open ended questions, please be as descriptive as possible to
improve accuracy of data. It may be helpful to have any supplements you may use nearby for
ease of survey completion.
Participation is voluntary, refusal to take part in the study involves no penalty or loss of benefits
to which participants are otherwise entitled, and participants may withdraw from the study at any
time without penalty or loss of benefits to which they are otherwise entitled.
If participants have further questions about this study or their rights, or if they wish to lodge a
complaint or concern, they may contact the principal investigator, Professor Natalie Caine-Bish,
at [email protected]; or the Kent State University Institutional Review Board, at (330) 6722704.*This survey has been approved by the Kent State University Institutional Research Board
(IRB)*
Consent If you are 18 years of age or older, understand the statements above, and freely consent
to participate in the study, click on the "I Agree" button to begin the survey.
 I agree (1)
 I do not agree (2)
If I do not agree Is Selected, Then Skip To End of Survey
91
APPENDIX B.
SURVEY QUESTIONNAIRE
Q1 Age:
 <`17 (1)
 18-19 (2)
 20-21 (3)
 22-23 (4)
 24-25 (5)
 >25 (6)
If <`17 Is Selected, Then Skip To End Of Survey
Q2 Gender:
 Male (1)
 Female (2)
Q3 Type of student:
 Undergraduate (1)
 Graduate (2)
Q4 Enrollment status:
 Part-time (1)
 Full-time (2)
Q5 Major or area of study:
Q6 How would you classify yourself?
 Non-athlete: A sedentary person who engages in little physical activity and exercises. An
individual in this category does not remain physically active greater than 30 minutes per day.
(1)
 Recreational Athlete: A person who exercises or remains physically active for general
purposes of health, wellness, personal enjoyment, stress relief, or improvement of physical
appearance. This is the category of exercisers often perceives more value in the health
benefits of exercise than competition. These individuals typically exercise approximately 30-
93
94
60 minutes per day, 3-5 days per week. Examples include: runners in a local 5k or halfmarathon, intramural sports teams, or recreation league sports. (2)
 Competitive Athlete: A person who exercises for the reasons associated with a Recreational
Athlete, but with a far greater emphasis on improving athletic-traits and competition. These
athletes compete to improve their personal best times, win single or team related events,
and/or qualify for or participate in elite competitions (non-NCAA affiliated). Examples of
this category include: Marathoners qualifying for the Boston Marathon, Ultra-Endurance
Athletes, or Triathletes qualifying for the IRONMAN World Championships, etc. (3)
 National Collegiate Athlete Association Athlete: A person who is a full-time college student
participating in sports through a National Collegiate Athlete Association (NCAA) team at the
university of attendance. This individual may exercise for the same reasons associated with a
Recreational and Competitive athlete. An athlete participating in NCAA sports are typically
considered to be at the elite level. (4)
Q7 Briefly describe your exercise routine in respect to: minutes/day, days/week, the type of
exercise, and a description of competitions of that you may participate in including the number of
competitions per year.
Q8 Do you use caffeinated coffee?
 Yes (1)
 No (2)
 I don't know (3)
If Yes Is Selected, Then Skip To Indicate the servings of usage per we...If No Is Selected, Then
Skip To End of BlockIf I don't know Is Selected, Then Skip To End of Block
Q9 Indicate the servings of usage per week. (1 serving = 8 fluid ounces)





1-3 servings per week (1)
4-6 servings per week (2)
7-9 servings per week (3)
10-12 servings per week (4)
12+ servings per week (5)
95
Q10 Indicate your beliefs related to reason for use.
Very
untrue (1)
Factors related to
exercise
performance
(strength, speed,
focus, stamina,
etc.) (1)
Untrue (2)
Neutral (3)
True (4)
Very true
(5)
I don't
know (6)
























Claimed health
benefits (5)






Taste/enjoyment
(6)






Convenience/Habit
(7)






Cognitive
performance (2)
General energy (3)
Weight loss or
body composition
changes (4)
Q11 Are there any other reasons why you use these products?
Q12 Do you use caffeinated tea?
 Yes (1)
 No (2)
 I don't know (3)
If Yes Is Selected, Then Skip To Indicate the servings of usage per we...If No Is Selected, Then
Skip To End of BlockIf I don't know Is Selected, Then Skip To End of Block
96
Q13 Indicate the servings of usage per week. (1 serving = 8 fluid ounces)





1-3 servings per week (1)
4-6 servings per week (2)
7-9 servings per week (3)
10-12 servings per week (4)
12+ servings per week (5)
Q14 Indicate your beliefs related to reason for use.
Very
untrue (1)
Factors related to
exercise
performance
(strength, speed,
focus, stamina,
etc.) (1)
Untrue (2)
Neutral (3)
True (4)
Very true
(5)
I don't
know (6)
























Claimed health
benefits (5)






Taste/enjoyment
(6)






Convenience/Habit
(7)






Cognitive
performance (2)
General energy (3)
Weight loss or
body composition
changes (4)
Q15 Are there any other reasons why you use these products?
97
Q16 Do you use energy/sports drinks containing any of the following: Caffeine, green tea,
Ephedra, Synephrine, Yerba Maté, Capsaicin, or other thermogenic/weight loss aids?An energy
drink is any of various types of beverage that are considered a source of energy, especially a drink
containing a high percentage of sugar and/or caffeine or other stimulant.Examples include: Red
Bull, Rockstar, Monster, Vitamin Water, and Sobe Life Water.
 Yes (1)
 No (2)
 I don't know (3)
If Yes Is Selected, Then Skip To List any products that you use:If No Is Selected, Then Skip To
End of BlockIf I don't know Is Selected, Then Skip To End of Block
Q17 List any products that you use:
Q18 Indicate the servings of usage per week. (1 serving = 8 fluid ounces or otherwise indicated
on the products label)





1-3 servings per week (1)
4-6 servings per week (2)
7-9 servings per week (3)
10-12 servings per week (4)
12+ servings per week (5)
98
Q19 Indicate your beliefs related to reason for use.
Very
untrue (1)
Factors related to
exercise
performance
(strength, speed,
focus, stamina,
etc.) (1)
Untrue (2)
Neutral (3)
True (4)
Very true
(5)
I don't
know (6)
























Claimed health
benefits (5)






Taste/enjoyment
(6)






Convenience/Habit
(7)






Cognitive
performance (2)
General energy (3)
Weight loss or
body composition
changes (4)
Q20 Are there any other reasons why you use these products?
Q21 Do you use nutritional supplements or diet pills containing any of the following: Caffeine,
green tea, Ephedra, Synephrine, Yerba Maté, Capsaicin, or other thermogenic/weight loss
99
aids? Examples include: Pre/Intra-workout supplements (C4, Jack3d, N.O. Xplode, etc.),
Hydroxycut, Super HD, and CLA with caffeine/thermogenic blend.
 Yes (1)
 No (2)
 I don't know (3)
If Yes Is Selected, Then Skip To List any products that you use:If No Is Selected, Then Skip To
End of BlockIf I don't know Is Selected, Then Skip To End of Block
Q22 List any products that you use:
Q23 Indicate the servings of usage per week. (1 serving = indicated on the products label)





1-3 servings per week (1)
4-6 servings per week (2)
7-9 servings per week (3)
10-12 servings per week (4)
12+ servings per week (5)
100
Q24 Indicate your beliefs related to reason for use.
Very
untrue (1)
Factors related to
exercise
performance
(strength, speed,
focus, stamina,
etc.) (1)
Untrue (2)
Neutral (3)
True (4)
Very true
(5)
I don't
know (6)
























Claimed health
benefits (5)






Taste/enjoyment
(6)






Convenience/Habit
(7)






Cognitive
performance (2)
General energy (3)
Weight loss or
body composition
changes (4)
Q25 Are there any other reasons why you use these products?
Q26 Do you use caffeine or stimulant gum?Examples include: Jolt gum, MEG gum, and Peak
Energy mints
 Yes (1)
 No (2)
 I don't know (3)
If Yes Is Selected, Then Skip To List any products that you use:If No Is Selected, Then Skip To
End of BlockIf I don't know Is Selected, Then Skip To End of Block
101
Q27 List any products that you use:
Q28 Indicate the servings of usage per week. (1 serving = indicated on the products label)





1-3 servings per week (1)
4-6 servings per week (2)
7-9 servings per week (3)
10-12 servings per week (4)
12+ servings per week (5)
Q29 Indicate your beliefs related to reason for use.
Very
untrue (1)
Factors related to
exercise
performance
(strength, speed,
focus, stamina,
etc.) (1)
Untrue (2)
Neutral (3)
True (4)
Very true
(5)
I don't
know (6)
























Claimed health
benefits (5)






Taste/enjoyment
(6)






Convenience/Habit
(7)






Cognitive
performance (2)
General energy (3)
Weight loss or
body composition
changes (4)
102
Q30 Are there any other reasons why you use these products?
Q31 Do you use Energy Gels containing caffeine?Examples include: Gu Roctane, Hammer Gel,
or Clif Shot
 Yes (1)
 No (2)
 I don't know (3)
If Yes Is Selected, Then Skip To List any products that you use:If No Is Selected, Then Skip To
End of BlockIf I don't know Is Selected, Then Skip To End of Block
Q32 List any products that you use:
Q33 Indicate the servings of usage per week. (1 serving = indicated on the products label)





1-3 servings per week (1)
4-6 servings per week (2)
7-9 servings per week (3)
10-12 servings per week (4)
12+ servings per week (5)
103
Q34 Indicate your beliefs related to reason for use.
Very
untrue (1)
Factors related to
exercise
performance
(strength, speed,
focus, stamina,
etc.) (1)
Untrue (2)
Neutral (3)
True (4)
Very true
(5)
I don't
know (6)
























Claimed health
benefits (5)






Taste/enjoyment
(6)






Convenience/Habit
(7)






Cognitive
performance (2)
General energy (3)
Weight loss or
body composition
changes (4)
Q35 Are there any other reasons why you use these products?
104
Q36 Where are you likely to receive nutritional supplement information?
Very
unlikely (1)
Family (1)
Friends (2)
Fellow athletes
(3)
Coaches/
Athletic
Trainers/
Personal
Trainers (4)
Doctors or
physicians (5)
Dietitians or
nutrition
professionals
(6)
Media: TV
commercials,
advertisements,
Magazines, etc.
(7)
Unlikely (2)
Neutral (3)
Likely (4)
Very likely
(5)
I don't
know (6)










































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