Aspects of body composition such as amount and distribution of body fat as well as amount and composition of lean body mass are now understood to be important outcomes in adults, infants, and children. Body composition is a key component of health for both individuals and populations. A perpetual epidemic of obesity in adults and children demonstrates the importance of body fat measurements for health short and long term. Body composition measurements predict body fat from body parameters and measurements. All techniques suffer from methodological and assumption errors by which data is converted to the end results. The multitude of these errors varies between techniques.
The most accessible method for measuring body composition is skin fold assessment which may use a three, four, and seven site analyses. The skin is pinched and while using skin fold calipers to measure skin fold thickness for each site. Each protocol has specific sites for testing across the body. The measurements are entered into the appropriate formula to estimate body composition. Skinfold calipers are relatively inexpensive making the skinfold method the most easily accessible. A proper skinfold assessment may be completed in a matter of minutes at any time and place. The skin fold method requires accurate readings from a handful of sites on the body making margin of error vary based on knowledge and experience of a technician.
Bioelectrical impedance is used to determine body composition. Bioelectrical impedance scales range from simple to complex. Lean tissue conducts electrical impulses quicker than fatty tissue. A faster response time is correlated with a leaner physique. Bioelectrical impedance monitors tend to be affordable. Bioelectrical impedance monitors can be found at many gyms and personal training studios. This technique requires very little effort so users need no previous practice and can be completed in a few seconds. Bioelectrical impedance measurements are generally much less accurate than DEXA scans. Readings can be affected by variables like hydration, mealtimes, and workouts.
Hydrostatic or underwater weighing compares a subject's normal weight to his or her bodyweight completely submerged. Using these weights and the density of water can allow operators to accurately assess the individual's body density that is used to estimate body composition. Hydrostatic weighing is a very accurate technique for measuring body composition. This technique uses tried and true variables with a low percentage of error. It is often considered the gold standard for measuring body composition and is used in research settings. The user must find a lab or performance center that offers hydrostatic weighing. As a result, this method can be inconvenient and more expensive than other techniques. Subjects must forcefully exhale as much air out of the lungs as possible and sit submerged completely underwater which can be uncomfortable for many. I have completed this technique and accomplishing this is especially difficult if you swim a lot because it feels extremely unnatural and can be quite difficult. We had three tries.
DEXA or Dual Energy X-ray Absorptiometry scan exposes patients to x-ray beams of differing intensities that can be used to determine bone mineral density and body composition. Participants lie on a table while a machine emits different energy x-ray beams. By measuring the absorption of each beam, the scan can determine bone mineral density, lean body mass, and fat mass. DEXA scan is advantageous because it involves lying on a table for a few minutes. Getting a DEXA scan usually involves making an appointment with a medical professional and the high level of accuracy comes with a high price tag compared to the other methods.
Air-displacement Plethysmography is like underwater weighing. The subject sits in a small machine like the BOD Pod while measuring the air displaced by the individual so body density can be determined. Body density is used to calculate body composition. This air displacement method uses a shape and size of machine that is more accommodating for people of any age, size, or shape. Like DEXA and hydrostatic weighing, air displacement plethysmography will probably not be at the local health facility.
The subject is encouraged to wait six to eight weeks between body composition measurements. The individual should find a body composition analysis that works for him or her and stick with it. Bioelectrical impedance and skinfold calipers may be slightly less accurate, but they can be an incredibly useful comparative tool. For more articles, please visit tpnperfectbodies.com