| Body Composition is the technical
term used to describe the different components that, when taken together,
make up a person's body weight. The human body is composed of a variety of
different tissue types. The so-called 'lean' tissues, such as muscle,
bone, and organs are metabolically active, while adipose (fat) tissue is
not.
Standard scales can
tell you a total weight, but can't determine the lean-to-fat ratio of that
weight. By the old height-weight charts, an athlete can be
"over-weight" and not "over-fat." A bodybuilder, for
example, may be 8% body fat, yet at 250 pounds may be considered
"over-weight" by a typical weight chart. In general, charts are
not a good indication of a athlete's ideal body weight for general health
or for athletic performance.
There are several different methods of assessing the percent of fat and
lean mass of an individual. These methods are referred to as Body
Composition Analysis.
The gold standard of body composition analysis is hydrostatic weighing
or hydrodensitometry. Although, because it is complex and complicated most
physiologists use simple
skinfold measurements to determine body fat percent. The American
College of Sports Medicine says that when performed by a trained, skilled,
tester, they are up to 98 percent accurate.
Bioelectrical Impedance is another method of assessing body fat
percentage. There are a variety of Body
Composition and Body Fat Analyzers and Scales available for home
use that provide more than just total weight measurements. These devices
determine total weight, the percent and amount of body fat, muscle mass,
water, and even bone mass. While the readings can be affected by hydration
levels, food intake, skin temperature, and other factors, if you follow
the directions and take the reading under similar conditions, you will
obtain the best results.
Ideal Body Weight and Body Fat Percent
Your ideal weight and fat-lean ratio varies considerably for men and
women and by age, but the minimum percent of body fat considered safe for
good health is 5 percent for males and 12 percent for females. The average
adult body fat is closer to 15-18 percent for men and 22-25 percent for
women.
Athletes tend to be at low end of this scale due to their increased
lean weight (muscle mass). While low levels of body fat seem to be related
to improved performance, body composition alone is not a great predictor
of sports success. A linebacker needs to have enough body mass (lean and
fat weight) to generate high forces and avoid injury. Body fat among elite
athletes vary largely by sport. There is little evidence of any benefit
when men drop under 8 percent and women drop under 14 percent body fat.
How Low Is Too Low?
While the average body fat percent in the United States and Europe is
increasing, extremely low body fat percent is also a health problem. The female
athlete triad highlights the problem. Women athletes who lose too
much fat risk injury, decreased performance and health issues.
The female athlete triad refers specifically to three related health
problems often found in women athletes:
This attempt to reduce body fat by extreme measures not only leads to
decreased exercise performance, but can lead to severe health
complications. Nutrient deficiencies and fluid/electrolyte imbalance from
low food intake can lead to increased risk of fractures, illness, loss of
reproductive function and serious medical conditions such as dehydration,
and starvation. The medical complications of this triad involve almost
every body function and include the cardiovascular, endocrine,
reproductive, skeletal, gastrointestinal, renal, and central nervous
systems.
Read the updated American College of Sports Medicine Position
Stand on the Female Athlete Triad.
How Much Is Too Much?
Just as too little body fat can cause physiological complications, too
much body fat is also harmful. For men over 25 percent and women over 32
percent fat there is a dramatic correlation with illness and disease.
Isn't Body Composition Genetic?
Some aspects of your body composition are genetic (where you store
fat), but most fat increase is related to lifestyle.
Can I Change My Body Composition?
Yes. To increase or decrease your percent of body fat you need to
create the right balance between the calories in and calories out. The
best way to do this is to decrease daily calories by about 500 and
increase your exercise. Aerobic exercise along with strength training is
ideal. If you are beginning a new exercise program, you are advised to
first consult your physician.
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