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5 - Body Composition
Body composition, which refers to the body’s relative amounts of fat and lean
body mass (organs, bones, muscles), is one of the five components of physical
fitness. Good body composition is best gained through proper diet and exercise.
Examples of poor body composition are underdeveloped musculature or excessive
body fat. Being overweight (that is, overly fat) is the more common problem.
Poor
body composition causes problems for the Army. Soldiers with inadequate muscle
development cannot perform as well as soldiers with good body composition. As
a soldier gets fat, his ability to perform physically declines, and his risk of
developing disease increases. Soldiers with high percentages of body fat often
have lower APFT scores than those with lower percentages. Poor body composition,
especially obesity, has a negative effect on appearance, self- esteem, and negatively
influences attitude and morale.
The Army’s weight control program is described
in AR 600-9. It addresses body composition standards, programs for the overly
fat, and related administrative actions.
The amount of fat on the body, when
expressed as a percentage of total body weight, is referred to as the percent
body fat. The Army’s maximum allowable percentages of body fat, by age and sex,
are listed in Figure 5-1. Evaluation
Methods
The Army determines body fat percentage using the girth method.
(This is described in AR 600-9, pages 12 to 21.)
Body composition is influenced
by age, diet, fitness level, and genetic factors (gender and body type). The Army’s
screening charts for height and weight (shown in AR 600-9) make allowances for
these differences. A soldier whose weight exceeds the standard weight shown on
the charts may not necessarily be overfat. For example, some well-muscled athletes
have body weights that far exceed the values for weight listed on the charts for
their age, gender, and height. Yet, only small percentage of their total body
mass may be fat. In such cases, the lean body mass accounts for a large share
of their total body composition, while only a small percentage of the total body
mass is composed of fat.
Soldiers who do not meet the weight standards for
their height and/or soldiers whose appearance suggests that they have excessive
fat are to be evaluated using the circumference (girth measurement) method described
in AR 600-9.
A more accurate way to determine body composition is by hydrostatic or underwater
weighing. However, this method is very time-consuming and expensive and usually
done only at hospitals and universities.
Soldiers who do not meet Army body
fat standards are placed on formal, supervised weight (fat) loss programs as stipulated
in AR 600-9. Such programs include sensible diet and exercise regimens. Diet
and Exercise
A combination of exercise and diet is the best way to lose
excessive body fat. Losing one to two pounds a week is a realistic goal which
is best accomplished by reducing caloric intake and increasing energy expenditure.
In other words, one should eat less and exercise more. Dieting alone can cause
the body to believe it is being starved. In response, it tries to conserve its
fat reserves by slowing down its metabolic rate and, as a result, it loses at
at a slower rate.
Soldiers must consume a minimum number of calories from all
the major food groups, with the calories distributed over all the daily meals
including snacks. This ensures an adequate consumption of necessary vitamins and
minerals. A male soldier who is not under medical supervision when dieting requires
a caloric intake of at least 1 ,500; women require at least 1,200 calories. Soldiers
should avoid diets that fail to meet these criteria.
Trying to lose weight
with fad diets and devices or by skipping meals does not work for long-term fat
loss, since weight lost through these practices is mostly water and lean muscle
tissue, not fat. Losing fat safely takes time and patience. There is no quick
and
easy way to improve body composition.
The soldier who diets and does
not exercise loses not only fat but muscle tissue as well. This can negatively
affect his physical readiness. Not only does exercise burn calories, it helps
the body maintain its useful muscle mass, and it may also help keep the body’s
metabolic rate high during dieting.
Fat can only be burned during exercise
if oxygen is used. Aerobic exercise, which uses lots of oxygen, is the best type
of activity for burning fat. Aerobic exercises include jogging, walking, swimming,
bicycling, cross-country skiing, rowing, stair climbing, exercise to music, and
jumping rope. Anaerobic activities, such as sprinting or lifting heavy weights,
burn little, if any, fat.
Exercise alone is not the best way to lose body fat,
especially in large amounts. For an average-sized person, running or walking one
mile burns about 100 calories. Because there are 3,500 calories in one pound of
fat, he needs to run or walk 35 miles if pure fat were being burned. In reality,
fat is seldom the only source of energy used during aerobic exercise. Instead,
a mixture of both fats and carbohydrates is used. As a result, most people would
need to run or walk over 50 miles to burn one pound of fat.
A combination of
proper diet and aerobic exercise is the proven way to lose excessive body fat.
Local dietitians and nutritionists can help soldiers who want to lose weight by
suggesting safe and sensible diet programs. In addition, the unit’s MFT can design
tailored exercise programs which will help soldiers increase their caloric expenditure
and maintain their lean body mass. |
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