Body Composition
Does the Scale Really Matter
Body composition is the term used to describe the different components that make up a person's body weight. The human body is composed of a variety of different tissue types including what we describe as lean tissues (such as muscle, bone, and organs) and fat. In the realm of fitness, it is often referred to the percent of "lean body mass" to "body fat".
The National Institute of Health recommends that a healthy adult male's body should have between 8 and 17 percent fat and a female should have 10-21%. Levels significantly above these amounts may indicate excess body fat. Athletes, leaner individuals, and more muscular individuals will have a body fat percentage lower than these levels. In general, most athletes experience greater performance benefits at body fat percentages between 7 and 19 percent for men, and 10 and 25 percent for women, depending on the sport.
In our weight conscience society, stepping on a scale usually determines whether we are at a desirable weight or not. However, what is truly important, and not measured by the traditional scale, is how much of that total weight is unhealthy fat. This is where body composition comes into play, thus showing a much truer picture of an individual's lean boy mass.
Body composition can be measured in several ways. The most common method is by using a set of measurement calipers to measure the thickness of subcutaneous fat in multiple places on the body. This includes the abdominal area, the subscapular region, arms, buttocks and thighs. These measurements are then used to estimate total body fat with a margin of error of approximately four percentage points.
Some of the other, not quite as common methods include bioelectrical impedance analysis (BIA), which uses the resistance of electrical flow through the body to estimate body fat, under water weighing, uses air, as opposed to water and is known as air displacement plethysmography (ADP), Dual energy X-ray absorptiometry (DEXA), which give accurate and precise measurements of body composition, including bone mineral content (BMC), bone mineral density (BMD), lean tissue mass, fat tissue mass, and %fat results, and finally through cross-sectional imaging methods like magnetic resonance imaging (MRI) and computed tomography (CT). MRI and CT scans give the most precise body composition measures to-date.
Irrelevant of the method used, testing your body composition accurately is a much more accurate and important measure of fitness and health, than weight taken on a scale alone. Someone who may be considered overweight by the scale alone, is not necessarily obese or unhealthy. The ideal weight and the fat to lean ratio varies considerably for men and women and by age. As a guide, the minimum percent of body fat considered safe and healthy is between 5 % and 8% for males and 12% to 15 % for females. As we age the percentage of body fat considered healthy slightly increases. On the other end of the chart, there is a dramatic correlation with illness and disease for men with body fat over 25% and women over 32%.
Reducing the levels of unhealthy body fat is another benefit of physical fitness. Different types of fitness training, such as cycling, swimming, and resistance training , is necessary to effectively address all the needs of the body. Reducing body fat is one of the most important components of fitness. Excessive levels of body fat are associated with cardiovascular disease, diabetes, cancer, and a variety of other illnesses.
