Sports
Performance 15
Section 3.2: Body
Composition
Body Composition
Body Composition
• The relative
percentage of
muscle, fat, bone
and other tissue
in the body
Body Composition
• Our primary
concern in this unit
is body fatness
and how it pertains
to athletic
performance
Body Composition
• Over Fat: higher
% of body fat than
within the normal
range
• ~ Males: greater than
25%
• Under Fat: lower
% of the body
made up of fat
• ~ Males: less than
5%
• ~ Females: less than
8%
• ~ Females: greater
than 30%
Body Composition
• The average male carries between 1517% body fat
• The average female carries between 1822% body fat
Body Composition
• Essential Fat: minimal amount of body fat
needed for normal physiological functions
• Why?
1- Temperature regulation
2- Shock absorption
3- Regulate essential body nutrients
Essential Fat:
Men- 3% of total weight
Women- 12% in women
Body Composition
• Obesity- a chronic disease characterized by
excessive body fat in relation to lean body mass
usually at least 20% above recommended body
weight
•A normal (average) sized
person has between 30 and
35 billion fat cells. When a
person gains weight, these
fat cells first increase in size
and later in number
•1lb of fat=3500 calories
Body Composition
• What you weigh is less
important than the
amount of fat you
possess
• Remember- lean muscle
mass weighs more than
fat
Body Composition
• Height/Weight ratio charts are a very general guideline
to health, and no where near as accurate as using a
body fat measurement to determine your status of health
Weight in pounds
overweight (bmi>25)
normal weight (bmi 20-25)
underweight (bmi<20)
Height in feet/inches
Body Composition
Body Composition
Body Composition
• As well as being too fat,
being too thin can
contribute to having
significant health problems
• Society pressures people to
develop the ‘perfect body’
• An increase in the number
of people suffering from
eating disorders is a direct
result of this pressure
Body Composition
• Anorexia Nervosa: increase
loss in body weight, failure to
eat, compulsive exercise,
vomiting; affects person’s
perception of themselvesmental disorder
• Bulimia Nervosa: binge eat,
then vomit to prevent digestionfailure to take in nutrients; body
weight fluctuates
Body Composition
• The eating disorders
mentioned effect a wide range
of people- including people of
all ages, and both sexes
• In the world of athletics many
people are also affected. It is
prominent amongst athletes in
sports where body type can
affect performance: figure
skating, dance, gymnastics
Body Composition
• How can we calculate body fat?
There are many different techniques that
vary in accuracy. No method can
ascertain your exact body fat percentage.
Body Composition
• Health indicators don’t necessarily measure body fat:
• 1. Height- Weight tables- Measures the ideal weight you
should be at for a certain height- does not account for body
frame
• 2. BMI (Body Mass Index)- Used as a health risk
assessment tool for the general population. Does not
assess body fat directly, however, coupled with knowledge
of a person’s exercise habits, it does give an accurate
indication of a person’s state of health
Body Composition
• BMI correlates with risk of disease and
death; for example, heart disease
increases with increasing BMI in all
population groups
• BMI is a measure of weight in relation to
height:
BMI= weight (kg)/ Height (m)²
OR
BMI= (weight [pounds]/height [inches] ²) x 703
Body Composition
• BMI will be inaccurate for many athletesno allowance for the fact that muscles
weighs more than fat
Body Composition
Body Composition
• If the BMI is near the upper end of the
range and nutritional and exercise habits
are poor, then the teen is likely to be
overweight
• If the BMI is near the lower end of the
range, nutrition is restrictive, and exercise
is excessive, there may be cause for
concern
Body Composition
• Skin Fold Measure (“fat pinching”):
using calipers, certain areas of the body
measured for body fat
• Easy to use, inexpensive, when used
correctly they are fairly accurate and
reliable
• Accuracy: + or -5%
Body Composition
• Girth Measurements:
• Simple method performed
by measuring
circumferences at specific
body sites
• Only a measuring tape
required and good accuracy
can be achieved
• Limitation for athletic people
or those that can not
visually by classified as thin
or obese
Body Composition
• Bioelectrical Impedance Analysis: calculates
body fat in seconds by running a weak electrical
current through the body
• Disadvantages- the amount of water in the body,
skin temperature, and physical activity
immediately prior to analysis can affect results
Body Composition
• Hydrostatic Weighing:
underwater technique for
measuring body composition;
considered the most
accurate body comp.
assessment techniques
• + or – 3% accuracy
• Disadvantages: expensive,
time consuming
Body Composition
• Hydrostatic Weighing continued:
• Calculate body density first, then measure
vital capacity of lungs and water
displacement as you first enter the water
tank
• An equation is used to calculate your body
fat, based on your density. The difference
in residual volume between the sexes is
accounted for.
Body Composition
• Air Displacement:
• Calculate the body
volume from the air
displaced by an
individual sitting inside a
small chamber
• High cost and still under
research although fast
and easy to administer
(5min); compares to
hydrostatic weighing
The Bod Pod
Body Composition
• DEXA-Dual Energy Xray Absorptiometry:
• Uses very low-dose beams
of X-ray energy to measure
total body fat mass, fat
distribution patterns, and
bone density
• Frequently used by research
and medical facilities
• Takes about 15min but not
readily available to people
(expensive)
Body Composition
• Fad diets accompanied by little exercise can
cause loss of muscle tissue as well as fat
• Scales do not show, what a person is losing?
Body Composition
• Typical person loses muscle and gains fat
starting at age 20
• Simple lifestyle changes can have a
dramatic effect on the aging process
• The loss of functional strength, increase in
body fat %, decrease in bone density,
reduction in flexibility and decline in
aerobic power are all under our control!
Body Composition
• Athletic performance: body fat hinders sports
performance and is directly related to injury
• Excess fat acts as dead weight- reducing speed and
efficiency of movement
• Detrimental to jumping, agility, and endurance activities
Body Composition
• Teen growth:
• Girls 10-13 years- stops around 16; spurt
hits first then weight
• Boys 12-15 years- stops around 18,
although some growth may take place until
21; height and weight spurt occurs at the
same time
Body Composition
• Our success as athletes comes from a
combination of athletic ability and our body
build
• There are 3 components to body build:
size, shape, and composition
Body Composition
Body Composition
• 3 extreme body types:
1. Endomorph:
•
•
•
•
Pear shaped
Wide hips and shoulders
Wider front to back rather than
side to side
A lot of fat on the body, upper
arms and thighs
Body Composition
2. Mesomorph:
• A wedge shaped body- cubical
head
• Wide broad shoulders
• Muscled arms and legs
• Narrow hips
• Narrow from front to back rather
than side to side
• A minimum amount of fat
Body Composition
3.
•
•
•
•
•
Ectomorph:
A high forehead
Receding chin
Narrow shoulders,
hips, chest, and
abdomen
Thin arms and legs
Little muscle and fat
Body Composition
• How can we control body fat?
- Regular exercise is effective: a
combination of aerobic exercise and
strength training helps maintain a high
metabolism and optimizes fat burning
Body Composition
• Basil Metabolic
Rate (BMR): the
minimal rate of
energy required to
maintain the life
processes of the
body at complete
rest
•BMR 5-10% lower in
women because of larger
percent of body fat and
smaller muscle mass
•BMR fastest during
growing years
•BMR gradually decreases
as you get older- the main
reason is because you lose
muscle mass as you get
older
Body Composition
• With a decrease in BMR and same eating
patterns= increase in body fat
• So to control fat, increase activity,
increase muscle mass= minimal changes
to BMR
• Cause of fatness = High calorie diet (food)
and low expenditure (exercise)
Body Composition
• To lose body fat = regular exercise and a
monitored diet
• To maintain body composition, must be a
balance in the exercise and the caloric
intake
• To increase lean weight = increase
calories and increase exercise