The ideal body composition
varies with different sports, but in general the less fat mass, the
greater the performance. The body is divided into two components, the
fat-free body mass and the fat mass. The fat free mass is composed partly
of muscle tissue, which does the work. Body composition refers to the
relative percentage of muscle, fat, bone, and other tissue of which
the body is composed.
The average male Olympic
cross-country skier is 25 years old, 5'10" tall, weighs 165 pounds
and has 5% body fat.
The average female Olympic
cross-country skiers is 25 years old, 5'7" tall, weighs 141 pounds,
and has 11% body fat.
Body Composition and Body Mass
The success of an athlete depends
a lot on the body type. Body size, build, and body composition can impair
or help performance. Athletic performance relates to body type (body shape
and size), and body composition (muscular development and amount of body fat).
Body fat contributes no strength advantage and limits endurance, speed, and
movement through space. Olympic cross country skiers are extremely lean compared
to average males and females.
The advantages of an appropriate
amount and distribution of body fat are:
shock absorption (football)
buoyancy (swimming)
thermal insulation (swimming)
fuel stores (cross-country skiing)
The average percent of body fat
values differ from sport to sport:
Basketball (men 9% and women 13%)
are higher than cross country skiing (men 5% and women 11%), but are much
lower than golf (men 13% and women 16%)
Training correctly can increase
muscle mass, and good nutrition and correct exercise can change body composition.
Olympic cross-country skiers need to be muscular for energy demands and lean
for good performance.
Essential and nonessential fat
Essential fat is necessary for
temperature regulation, shock absorption, and regulation of essential body
nutrients. Nonessential fat is the result of taking in more calories than
you expend. When nonessential fat accumulates in excessive amounts, and individual
may become overfat.
Overfat is more important than
overweight in determining health and wellness. The body mass index (BMI) is
probably the best way to use height and weight to assess fatness. The BMI
can provide guidelines for body fatness, but is not a true measure of body
fatness. Thus, it should not be used to assess performance. A person who has
a large muscle mass as a result of regular exercise could appear to be overweight
using a height and weight table.
Caculate your Body Mass Index:
Divide your weight in punds
by 2.2 to determine your weight in kilograms
Multiply your height in inches
by .0254 to determine your height in meters
Square your height in meters
(multiply your height in mters by your height in meters).
Divide the value you obtain
in step 3 into your weight in kilograms (step 1).
Because the amount of body fat,
not the amount of weight, is the important factor in living a healthy life,
it is better to determine the percentage of your body weight that is body
fat (percent body fat). Measurement of body fat can be done by underwater
weighing which is the gold standard, determining body volume, bioelectric
impedance, and skinfold thickness. These methods are estimates and can all
produce different numbers. We can assess body composition by many methods.
Perhaps the most used is the skinfold assessment.
Evaluating body fatness
Skinfold measurements are made
with skinfold calipers. The following procedures must be used for each skinfold
site:
Use your thumb and index finger
of both hands to "draw up" a layer of skin and fat.
"Draw up" the skinfolds
in a vertical line. Do not pinch the skinfold.
Once you have drawn the skinfold,
let go with your right hand and pick up the caliper.
Place the jaws of the caliper
over the location of the skinfold, allow the tips of the caliper to close
n the skinfold at a level about where the skin would naturally be.
Let the caliper adjust for two
or three seconds, not the thickness of the skinfold in millimeters.
Three measurements should be
taken at each site. Use the average to determine your measurement.
Skinfold location for women
Triceps - One half the distance
between the soulder and elbow, use your dominant side.
Iliac Crest - Diagonally on
the natural line of the skin on the iliac crest.
Abdominal - One inch to the
right of the navel
Skinfold loactions for men
Thigh - See above
Chest - Above and to the right
of the right nipple. May be done diagonally.
Abdominal - One inch to the
right of the navel
Calculating fatness from the
skinfold
Sum the three skinfolds
Use the skinfold sum and your
age to determine your percent fat in the body
composition chart.
