BODY COMPOSITION
WHAT IS BODY COMPOSITION?
How the body is made up. Split into 2 components.
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Fat mass refers to a persons percentage of body
weight stored as fat (within adipose tissue)
Lean body mass, weight of the rest of the body
(bones, muscles, organs, tissue)
Height and weight are not always a good
indicator of body composition
AVERAGE PERCENTAGE FAT MASS
Sport
Male %
Female %
Baseball
12-15
12-18
Basketball
6-12
20-27
Cycling
5-15
15-20
Field Hockey
8-15
12-18
Rowing
6-14
12-18
Swimming
9-12
14-24
Track – Runner
8-10
12-20
Track – Jumper
7-12
10-18
Track – Thrower
14-20
20-28
Triathlon
5-12
10-15
Volleyball
11-14
10-15
SIZE IN RELATION TO SPORT
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Every sport has an ideal size for their
requirement e.g. Compare high jump to sumo
what are the needs of the competitors?
Weight is not that important its body composition
that an athlete will be concerned about
Muscles weighs around 3 times more than fat so
being heavier may not be a detriment
BODY MASS ASSESSMENT
Hydrostatic Weighing
 Athlete submerged in water
 Difference between dry and wet weight
gives percentage fat
 Fat is less dense and floats in water
 Most common and accepted method
 Most accurate but least available method
 Only estimated density of fat which varies
to age, gender, race
BODY MASS ASSESSMENT
Bioelectrical Impendence Spectroscopy (BSI)
 Low safe electrical current passed through
body on body fat scales
 Fat gives resistance to current (impedance)
 Results set against height and weight chart,
scales then give % fat
 Measurement is affected by hydration
 It uses estimates of population so not
appropriate for elite athletes with more
lean muscles tissue
BODY MASS ASSESSMENT
Skinfold measurement
 Skinfold callipers measure in mm the level
of fat below skin from selected body sites
 Sum of these measurements estimates fat %
 Locations vary but usually, tricep, bicep,
subscapular and suprailliac
 Most widely used as cheap
 Lots of measurements so accurate
 Testers need to be trained and measure
specific sites
SKINFOLD CALLIPERS
SITE
METHOD
TRICEP
Take a vertical skinfold parallel to
upper arm, halfway between the
shoulder and the elbow
SUBSCAPULA
Take a diagonal skinfold across the
back, just below the shoulder blade
BICEP
Take a vertical skinfold halfway
between the elbow and the top of
the shoulder on the front of the
upper arm
SUPRAILIAC
Take a diagonal skinfold along the
line of the iliac crest just above the
hip bone
PICTURE
BODY MASS INDEX (BMI)
Measure of weight against height
 Weight in Kg’s / Height in Metres Squared
 Men range 20.1-25.0 Women range 18.5-23.8
 Does not directly measure fat but is
correlated to body composition
 Better estimate to overweight/obesity than
other methods
 Not suitable, for young, elderly, pregnant or
athletes
 Athletes heavy muscles mean this is
disproportionate
 Used a government standard test for health
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BMI SCALE
Below 18.5
 18.5-24.9
 25-29.9
 30-34.9
 35+
Underweight
Normal
Overweight
Obese
Very obese
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Calculate this BMI
 Weight 124 KGs Height 1.96 m
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1.96 x 1.96 = 3.84 m2
124 / 3.84 = 32.3
BMI JONAH LOMU
OVERWEIGHT AND OBESITY
Occur as a result of an imbalance between energy
intake and energy expenditure
 If energy intake is greater than expenditure
weight will increase
 However increasing muscle mass will also will
also increase weight!
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ENERGY EXPENDITURE
Basal Metabolic Rate (BMR)
 The lowest amount of energy required for
minimum energy expenditure at normal rest
levels (after 8hrs sleep and 12 hrs fasting)
Resting Metabolic Rate (RMR)
 Does not include the measure of sleep so is
generally used more frequently
AN AVERAGE DAY
60-75% is RMR
 20-30 Physical activity
 Rest energy used when eating, absorbing and
digesting food (thermic effect)
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Add all 3 to get Body's Total Metabolic Rate
ENEGY INTAKE
On average men 2550 calories, women 1940 per
day.
 Varies depending on?
 Lifestyle, age, height, weight, activity, body
composition.
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A balanced diet looks like this (%’s)
 10-15 protein
 No more than 30 fat
 55-60 Carbohydrate
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CALORIE INTAKE
Obviously the balance between energy intake and
energy expenditure determines your total body
weight
 Balance of the 5 a day? Find these out
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Depending on your diet calories can come from
proportionally the 3 energy fuels, carbs, fats,
proteins
HEALTH IMPLICATIONS
Diabetes
 Cancer
 Cardio-vascular disease
 Joint stress
 psychological harm
 Under performance
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INFO FOR EXTENDED QUESTIONS
Huge increase in past 10 years
 Britons amongst heaviest in Europe
 By 2050 60% men, 50% women clinically obese
 Only 5% of children walk to school 80% 20 years
ago
 Cost of obesity to UK society by 2050 £50 Billion
 Obesity causes 18 sick days per year
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EFFECTS OF PHYS ACT. ON BODY COMP
Increase activity means increased number of
calories burned
 Increased calorie burn even when activity has
stopped post-exercise
 Increases lean body tissue which burns more
calories
 Exercise increases the mobilisation of fats as
energy fuel
 Therefore increase RMR when even at rest
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