BREAK IT UP
Improving Health by Breaking Up Continuous
Bouts of Sedentary Behavior
by Brooke E. Starkoff, Ph.D., and Elizabeth K. Lenz, Ph.D.
LEARNING OBJECTIVE
Sedentary behavior will be defined and differentiated from physical
inactivity. The reader will learn about the negative health implications
associated with sedentary behavior and how to break up continuous
bouts of sedentary activities with physical movement.
Key words:
Breaks, Cardiovascular Health, Light Activity, Physical Activity,
Sedentary
Current trends have not only highlighted a
dramatic increase in sedentary behavior during the
last 40 years but also have determined the
significant health risk associated with too much
sitting. In this article, we will discuss changes in
our work/school day, transportation, surrounding
environment, and leisure time activities that have
contributed to this spike in sedentary behavior. We
will discuss the negative impact on overall health,
differentiate between physical inactivity and
sedentary behavior, and highlight the benefits of
adding in spurts of light physical activity to break
up prolonged sedentary activities.
DEFINITION AND TRENDS
INTRODUCTION
A
s health care practitioners, we are well
aware of the health benefits associated
with daily moderate to vigorous physical activity (MVPA) and the importance of
meeting the American College of Sports Medicine’s physical activity guidelines (Table 1).
However, did you know that even those who
acquire 30 minutes of MVPA most days of the
week may still be at risk for death and disease if
they engage in excessive amounts of sedentary
behavior for the remainder of the day? In fact,
prolonged sedentary behavior also may contribute to chronic conditions such as
cardiovascular disease (CVD) and
type 2 diabetes mellitus (T2DM).
Assuming 8 hours of sleep, current
physical activity recommendations
make up a small portion of our day,
approximately 3% of waking hours.
So what are people doing the other
15 to 16+ hours they are awake?
And what about the nearly 50% of
Americans who do not participate in
150 minutes or more of aerobic physical activity per week?
14
The unfortunate truth is that a substantial number
of Americans are spending an inordinate amount of
time engaging in sedentary behaviors, defined by
the Sedentary Behaviour Research Network as
‘‘any waking activity characterized by an energy
expenditure e1.5 metabolic equivalents and a
sitting or reclining posture’’ (13). Total sedentary
behavior refers to the total accumulated time spent
sedentary per day, whereas prolonged sedentary
behavior refers to a continuous bout of a specific
activity such as sitting/reclining while watching
television and/or working on the computer. A
recent study found that, in the United States,
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VOL. 19/ NO. 2
TABLE 1: American College of Sports
Medicine Physical Activity Recommendations
Adults
Children
• Q5 days per week of moderate
exercise or Q3 days per week
of vigorous exercise; or a
combination of the two Q3 to
5 days per week
• 60 minutes or more of
moderate-to-vigorous
physical activity daily
• 30 to 60 minutes per day
(150 minutes per week) of
purposeful moderate exercise;
or 20 to 60 minutes of vigorous
exercise; or a combination of the two
• 1 continuous session or multiple
short bouts of exercise
(Reprinted from Garber CE, Blissmer B, Deschenes MR, et al. American
College of Sports Medicine position stand. Quantity and quality of exercise for
developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor
fitness in apparently healthy adults: guidance for prescribing exercise. Med. Sci.
Sports Exerc. 2011;43(7):1334Y59.) Used with permission.
children and adults accumulate more than 7.5 hours per day of total
sedentary time, typically consisting of prolonged bouts of sedentary
behavior (12). Even more alarming are the trends in time spent
sedentary across the age span such that, as one ages, total sedentary
time increases (12).
Historic trends reveal that we spend far more time engaging in
sedentary behaviors now than 60 years ago, largely as a result of
changes in transportation, built environment, technology, and the
workforce/school day. Trends in transportation, for example, have
shifted such that automobiles are no longer considered a luxury, and,
instead, have become essential for travel. Furthermore, not only does
owning a car reduce the likelihood of walking or biking to a
destination but also we spend significantly more time sitting in
traffic compared with 30 years ago, contributing to an even greater
amount of time being stationary in our vehicles (1). Likewise,
changes to our surrounding environment, known as built environment, further promotes sedentary lifestyles. This includes lack of
sidewalks or bike paths and access to parks/recreation centers in
some neighborhoods, making it exceedingly difficult for many to
engage in active transportation or physical activity. Safety also is of
paramount importance, and lack of safe parks and recreation centers
at which to play forces people to participate in more home-based
sedentary activities during leisure time (i.e., watching television or
playing video games) and, subsequently, contribute to increased
time spent viewing television and movies, playing video games, and
‘‘surfing the net.’’ Currently, we watch at least twice as much
television as we did in the 1950s, with the average U.S. household
increasing television viewing by 36 minutes every 10 years (1).
In addition, during the last 60 years, there has been an increase
in jobs requiring little or no physical activity and a reduction in
highly active occupations, including agricultural employment,
which has fallen dramatically since 1950 (1). Our schoolchildren
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spend a large portion of their day sedentary as well potentially
because of the decrease in time allocated for recess and physical
education. It may be possible that physical activity is reduced
further in the transition from elementary to high school and high
school to college/workforce as people spend more time studying/
working, subsequently contributing to increased sedentary time
with aging. In fact, stability of sedentary behavior has been
identified from adolescence into adulthood (5). It may be that, as
young individuals become accustomed to a sedentary society, they
may recognize it as a way of life and maintain those habits
throughout adulthood.
SEDENTARY BEHAVIOR AND HEALTH IMPLICATIONS
Whereas we strive to remind our clients of the countless benefits
associated with habitual exercise, it may be even more beneficial
to educate them on the negative consequences of prolonged and
total sedentary behavior. During the last decade or so, researchers
have focused on examining the impact of sedentary time on health
(8,11,14). Many are aware that these activities require little muscle
movement, equating to low levels of energy expenditure and,
subsequently, very few calories burned. Therefore, the risks of
overweight and obesity are a concern for those accumulating large
amounts of sedentary behavior. Yet, the risks go far beyond weight
gain; in large epidemiologic studies, researchers have found that
sedentary behavior is associated with increased death from all
causes, CVD, and metabolic risk variables, including (7,9,11):
Men and women:
• j waist circumference
•
j blood pressure
j plasma glucose
Women:
• j body mass index
•
•
j fasting glucose
•
j triglycerides
, high-density lipoproteins
Furthermore, several studies have shown a dose-response
relationship such that greater amounts of total time spent sitting
resulted in increased risk of disease. For instance, a large cohort of
women demonstrated that, for each 2-hour per day increase in time
spent watching television, there was a 23% increase in risk for
obesity and a 14% increase in the risk for T2DM (9). This is
particularly alarming because our current daily habits and activities
are conducive to prolonged sedentary behavior, rather than short
bursts, contributing more so to the overall total time being sedentary.
•
SEDENTARY VERSUS PHYSICAL INACTIVITY
As most health care professionals strive to improve the healthrelated physical fitness of their clients by improving cardiovascular fitness, muscular strength and endurance, flexibility,
and body composition, MVPA often is prescribed in the form of
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Break It Up
gests that sedentary and light-intensity activities have opposing
effects on health (8,9). In fact, greater amounts of time spent
standing are related to decreased mortality rates from all causes and
CVD (10). Simply moving from sitting at a desk to a standing
position, for example, not only reduces time spent in prolonged
sedentary behavior but also incorporates muscle movement,
initiating a cascade of physiology that may contribute to improved
health (14). Hence, it is essential to distinguish between sedentary
and light activities when offering clients and patients tips on how to
be more active and less sedentary (Table 2). Furthermore, it is
important to remind clients that even light-intensity activity is better
for overall health than remaining sedentary.
structured exercise, such as walking or running at a specific
intensity, time, and frequency per week. In general, we want to
assist our clients in achieving healthy lifestyles. In addition to
MVPA, it is important to discuss, identify, and define other
behaviors that can benefit overall health (Table 2). As stated
previously, sedentary behaviors, including sitting, lying, or
reclining quietly, require very little or no muscle movement and
may impact blood lipid profiles and glucose metabolism
negatively, contributing to increased risk for chronic diseases
such as CVD and T2DM (7,11,14). Therefore, it is of
paramount importance to educate clients on the awareness of
these activities when trying to reach a health-related physical
fitness goal.
Although the terms often are used interchangeably, sedentary
and physically inactive are distinctly different. Contrary to sedentary
behavior, physical inactivity refers to light movement or the lack of
achieving physical activity recommendations (14). Evidence sug-
TABLE 2: Examples of Sedentary, Light, and
Moderate-to-Vigorous Physical Activities
Sedentary (e1.5 METs and sitting
or reclined)
Lying/sitting quietly (watching
TV, listening to music)
Sitting at a desk
Meditating
Knitting
Light (91.5 METs to
G3 METs)
Standing (cooking, laundry,
ironing, cleaning)
Walking slowly
Playing cards, darts, musical
instrument
Grocery shopping
Moderate-to-vigorous
(93 METs)
Basketball
Dancing
Running
Walking briskly
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‘‘ACTIVE COUCH POTATO’’
Even those accumulating recommended amounts of MVPA are at
risk for disease if they also engage in prolonged sedentary
activities. This concept has been referred to affectionately as the
Active Couch Potato phenomenon (7). Although some do
participate in daily MVPA, they also may be spending copious
amounts of time engaging in sedentary behavior. The detrimental
impact of prolonged sedentary behavior to blood pressure, weight,
and glucose metabolism was not only evident in those who did not
attain sufficient physical activity but also in subjects accumulating
150 minutes or more of MVPA per week (7). It has been found
that time spent watching television was not associated with time
spent participating in MVPA, further highlighting the independent
risk factors of sedentary behavior and physical inactivity. Even
those participating in 1 hour of daily MVPA could not negate the
effects of inactivity on glucose metabolism and cholesterol if they
were sedentary for the remainder of the day (3). The risk of
disease, therefore, seems to be more a result of prolonged
sedentary behavior rather than too little time spent with physical
activity (3,7,8). In fact, some findings suggest that excessive
sedentary time may play a larger role in contributing to some
metabolic risk variables than the accumulation of recommended
time with MVPA (8). Although MVPA does play a significant role
in contributing to improved health, it may be imperative that we
identify methods for individuals to incorporate various short bursts
of movement into their daily routine in addition to current MVPA.
For those not accumulating recommended amounts of MVPA, this
becomes increasingly important.
Replacing prolonged sedentary time with multiple short breaks
has contributed to improvements in blood pressure, waist
circumference, triglycerides, and glucose metabolism, even when
the activities are of light intensity (3,6,7). In fact, one study
identified a 12% decrease in the risk of T2DM for each 2-hour per
day increase in time spent standing or walking around at home (9).
Another study found that replacing prolonged sitting with light
walking or standing throughout the day was more effective in
improving insulin and lipid levels than adding 1 hour of MVPA (3).
Although these physical activity breaks are not specifically designed
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to increase physical fitness significantly, they will decrease
sedentary time and, ultimately, aid in the reduction of risk factors
for many chronic diseases.
SEDENTARY BEHAVIOR RECOMMENDATIONS
Presently, there are no specific guidelines in the United States to
reduce total sedentary behavior for adults. To ward off the negative
health impact of sedentary behaviors across a lifetime, the
American Academy of Pediatrics has developed the following
recommendations for the reduction of sedentary behavior in youth:
• Limit screen time to less than 1 to 2 hours per day
•
Discourage screen media exposure for children younger
than 2 years
•
Keep the TV set and Internet-connected electronic devices
out of the child’s bedroom
•
Model active parenting by establishing a family home use
plan for all media
) As part of the plan, enforce a mealtime and bedtime
‘‘curfew’’ for media devices, including cell phones.
Establish reasonable but firm rules about cell phones (2).
The most recent ACSM Position Stand, ‘‘Quantity and
Quality of Exercise for Developing and Maintaining Cardiorespiratory, Musculoskeletal, and Neuromotor Fitness in
Apparently Healthy Adults: Guidance for Prescribing Exercise,’’ does recognize that sedentary behavior is a health risk,
and that achieving physical activity recommendations does not
negate sedentary behavior. Furthermore, the updated recommendations urge the reduction of prolonged time spent in
sedentary behavior by suggesting the addition of short frequent
bouts of standing or participating in other physical activity
between periods of sedentary behavior (4).
It may, therefore, be appropriate to add the following
recommendation to the current physical activity guidelines:
Reduce prolonged sedentary behavior to no more than
60 minutes at a time and break it up with bouts of any
intensity activity.
Figure. Examples of ways to break up traditional sedentary behaviors.
VOL. 19/ NO. 2
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17
Break It Up
potentially unrealistic goal, many will still benefit from making small
changes in their current routine. Shifting from traditionally sedentary
behavior to light activity may be a great jumping-off point and may
aid in the introduction of MVPA into their daily routine. Likewise, it
is important that we remind our physically active clients that they are
not completely exempt from the poor health effects associated with
sedentary behavior. Helping clients achieve MVPA recommendations
combined with a concurrent reduction in sedentary time should be
our end goal. In fact, almost everyone can benefit from reducing
sedentary behavior by incorporating physical activity breaks and
remembering to break it up!
References
Rather than prescribe a specific duration for the breaks in
sedentary behavior, health practitioners should focus more on
encouraging greater frequency of movement throughout the day
to avoid prolonged sitting. In addition, suggestions should be
offered for modes of incorporating various intensities of
physical activity into traditionally longer bouts of sedentary
behaviors. See figure for some examples by which traditional
sedentary behaviors can be broken up with physical activity.
Assessing sedentary behavior should be a component of the
initial consultation between health care providers and their clients.
When obtaining health history information, including current and/or
previous involvement with physical activity, it also may be
beneficial to identify current specific sedentary activities in which
your client participates and how long he or she spends with those
activities at one time. To determine this behavior, clients can
complete a sedentary behavior diary or log; they can be provided
with a physical activity-tracking device, such as a pedometer or
accelerometer; or clients can be shown how to use a variety of
phone applications (‘‘apps’’) with which they can log their behaviors
as well as receive reminders to be active throughout the day. Once
the magnitude of the behavior is identified, clients can record daily
reductions in sedentary behavior through increased steps and
challenge themselves or a friend to decrease sedentary behavior each
week with increased step counts. Having clients set a daily goal for
steps may be the best approach for short-term goal setting. However,
even without means to measure activity objectively, health care
providers can work with their clients to focus on identifying one
specific sedentary behavior in which they currently engage and add
in frequent small breaks as often as possible.
CONCLUSIONS
Oftentimes, for those currently accumulating significant amounts of
sedentary behavior, prescribing traditional exercise or prohibiting
participation in sedentary activities may not be a realistic solution.
Although the current physical activity recommendations should be
the ultimate goal for currently sedentary clients, it may be particularly
daunting and overwhelming for them to initially aim for 150 minutes
per week of MVPA. Rather than discourage them by setting a
18
1. Brownson RC, Boehmer TK, Luke DA. Declining rates of physical
activity in the United States: what are the contributors? Annu Rev Public
Health. 2005;26:421Y43.
2. COMMUNICATIONS CO, MEDIA. Children, adolescents, and the
media. Pediatrics. 2013;132(5):958Y61.
3. Duvivier BM, Schaper NC, Bremers MA, et al. Minimal intensity
physical activity (standing and walking) of longer duration improves
insulin action and plasma lipids more than shorter periods of moderate
to vigorous exercise (cycling) in sedentary subjects when energy
expenditure is comparable. PLoS One. 2013;8(2):e55542.
4. Garber CE, Blissmer B, Deschenes MR, et al. American College of
Sports Medicine position stand. Quantity and quality of exercise for
developing and maintaining cardiorespiratory, musculoskeletal, and
neuromotor fitness in apparently healthy adults: guidance for prescribing
exercise. Med Sci Sports Exerc. 2011;43(7):1334Y59.
5. Gordon-Larsen P, Nelson MC, Popkin BM. Longitudinal physical
activity and sedentary behavior trends: adolescence to adulthood. Am J
Prev Med. 2004;27(4):277Y83.
6. Healy GN, Dunstan DW, Salmon J, et al. Breaks in sedentary time:
beneficial associations with metabolic risk. Diabetes Care.
2008;31(4):661Y6.
7. Healy GN, Dunstan DW, Salmon J, Shaw JE, Zimmet PZ, Owen N.
Television time and continuous metabolic risk in physically active adults.
Med Sci Sports Exerc. 2008;40(4):639Y45.
8. Healy GN, Wijndaele K, Dunstan DW, et al. Objectively measured
sedentary time, physical activity, and metabolic risk: the Australian
Diabetes, Obesity and Lifestyle Study (AusDiab). Diabetes Care.
2008;31(2):369Y71.
9. Hu FB, Li TY, Colditz GA, Willett WC, Manson JE. Television watching
and other sedentary behaviors in relation to risk of obesity and type 2
diabetes mellitus in women. JAMA. 2003;289(14):1785Y91.
10. Katzmarzyk PT. Standing and mortality in a prospective cohort of
canadian adults. Med Sci Sports Exerc. 2014;46(5):940Y6.
11. Katzmarzyk PT, Church TS, Craig CL, Bouchard C. Sitting time and
mortality from all causes, cardiovascular disease, and cancer. Med Sci
Sports Exerc. 2009;41(5):998Y1005.
12. Matthews CE, Chen KY, Freedson PS, et al. Amount of time spent in
sedentary behaviors in the United States, 2003-2004. Am J Epidemiol.
2008;167(7):875Y81.
13. Network SBR. Letter to the Editor: Standardized use of the terms
‘‘sedentary’’ and ‘‘sedentary behaviours.’’ Appl Physiol Nutr Metab.
2012;37(3):540Y2.
14. Thosar SS, Johnson BD, Johnston JD, Wallace JP. Sitting and endothelial
dysfunction: the role of shear stress. Med Sci Monit. 2012;18(12):
RA173YRA180.
ACSM’s HEALTH & FITNESS JOURNALA | www.acsm-healthfitness.org
Copyright © 2015 American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
VOL. 19/ NO. 2
Recommended Reading
Dunstan DW, Howard B, Healy GN, Owen N. Too much sitting V a health
hazard. Diabetes Res Clin Pract. 2012;97:368-76.
Hamilton MT, Healy GN, Dunstan DW, Zderic TW, Owen N. Too little
exercise and too much sitting: inactivity physiology and the need
for new recommendations on sedentary behavior. Curr Cardiovasc
Risk Rep. 2008;2(4):292Y8.
Owen N, Healy GN, Matthews CE, Dunstan DW. Too much sitting: the
population-health science of sedentary behavior. Exerc Sport Sci Rev.
2010;38(3):105.
Disclosure: The authors declare no conflict of interest and do
not have any financial disclosures.
Brooke E. Starkoff, Ph.D., is an assistant
professor of exercise science at The College
at Brockport, SUNY, where she teaches
courses on obesity, as well as cardiac
rehabilitation. Her research focus is on
obesity and the role of exercise in improving
heart function in children with obesity.
VOL. 19/ NO. 2
Elizabeth K. Lenz, Ph.D., is an assistant
professor of exercise science at The College
at Brockport, SUNY, where she teaches
courses on exercise physiology, exercise
testing and prescription, and exercise programming. Her research focus is on measurement and assessment of sedentary behavior
and physical activity and their impact on health.
BRIDGING THE GAP
Continuous bouts of sedentary behavior are associated with
increased risk of diseases, even in individuals achieving
recommended amounts of daily physical activity. Therefore, it
is beneficial to break up sedentary activities with short spurts
of movement including light or moderate activity, such as
standing up, dancing, or taking a 1- to 3-minute walk.
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