Body fat percentage is the percentage of an individual’s weight represented by fat versus lean tissues, such as muscle. Using various forms of tests, athletes and coaches can gain useful information regarding their training and nutrition plans. While body fat percentage is commonly thought of as a performance indicator, body fat testing can also play a role in safety.
Body fat percentage is an important conditioning measure because muscle and fat play different roles in athletic performance. Muscle is what allows an athlete to exert force, while fat plays no direct role in strength. An athlete who is 200 lbs. at 9 percent body fat will most likely be stronger and more powerful than one who is 200 lbs. and 20 percent body fat.
There are several methods used to test body fat percentage, all with their advantages and disadvantages. The most accurate way to test best body fat is through use of a dual-energy x-ray absorptiometry machine, which is the same machine used to measure bone density. However, this method is expensive and done primarily in hospitals and clinical settings. Two more popular methods are weighing in water and skin fold calipers. Weighing an athlete in water is considered the more accurate method of the two, but it is typically more expensive. Most athletes and coaches rely on a skin fold caliper, which estimates an athlete’s body fat percentage based on skin thickness at specific anatomical sites. Although not quite as accurate as water weighing, it is far easier to perform.
Leaner is not always better. While some athletes should strive for low body fat percentages, others need more body fat for optimal performance. Athletes who rely on speed, endurance and agility, such as sprinters, cyclists and gymnasts often strive to be as lean as possible to avoid carrying unnecessary weight. Others, such as football offensive linemen need more body fat for mass, weight and protection from constant hits. For some specialized athletes, such as baseball pitchers, body fat levels will vary greatly, with no apparent ideal body type.
Body fat percentage is an important safety tool because it can be used to identify athletes who are either too fat or too lean to safely engage in their sport. When a football lineman shows up for summer training camp following the off-season, his coach may test his body fat to see if he has put on too much body fat to practice in the summer heat with pads. In the case of a college wrestler, a body fat test will show if that athlete is already too lean to safely compete at a lower weight class.
How Low is Too Low?
Although a low body fat percentage can have a positive effect on performance, there is a point at which an athlete may actually see a decline in performance or health. The human body carries a small amount of fat, such as the fat in your organs, that is considered essential for normal functioning. According to Asker Jeukendrup and Michael Gleeson in "Sport Nutrition," this amount is 3 percent for men and 12 percent for women. Below this amount athletes may be at a greater risk of illness and injury.
- "Essentials of Strength Training and Conditioning, 3rd Edition"; National Strength and Conditioning Association; 2008
- "The Metabolic Diet"; Mauro Di Pasquale M.D.; 2000
- Scientific American: Going for the Gaunt: How Low Can an Athlete's Body Fat Go?
- Sport Nutrition, Asker Jeukendrup, Ph.D. and Michael Gleeson, Ph.D.
- fat measure image by Kimberly Reinick from Fotolia.com
This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.