In addition, since with physical exercise, body fat can turn down while muscle mass can increase, net changes in body weight cannot constantly predict body fat levels. Changes in body fat levels can be followed as part of charting progress during training.
Unfortunately, body fat determination is not clear-cut compared to height, weight, aerobic fitness, or muscle determinations.
The main standard for body fat assessment is hydrostatic weighing, which involves being completely submerged underwater after expelling as much air from your lungs as possible. Characteristically, at least 4 or 5 attempts are necessary to achieve a stable weight measurement. Obviously, not everyone can comply with the actions, nor is the requisite equipment commonly available. A more recent methodology introduced that is qualitatively similar to underwater weighing is the Bod PodTM . This device measures total body volume by air displacement in a specialized enclosed chamber. While technically easier than underwater weighing, this equipment is currently even less available than underwater weighing.
An additional recently introduced method is called dual-energy x-ray absorptiometry or DEXA for short. DEXA uses a three compartment model dividing the body into total body mineral, mineral-free lean tissue, and fat mass. Agreement with earlier methods is good; however, DEXA suffers from standardization issues at present. Results can vary with the specific equipment manufacturer, data collection methods, and software analysis 31. In the future, as methodologies are uniformed and the equipment becomes more widely available, DEXA may develop into the medical body fat assessment technique of choice, partly due to its simplicity from the standpoint of the subject as well as providing valuable information regarding bone mineral content
Sorry to say, advice for determining whether to use the regular or athletic formula is based on duration of weekly activity which limits utility for tracking progress with increasing training load, since it’s not obvious when someone changes from a mere adult to an athlete. In some cases, the results can vary substantially flanked by the two settings which is more reflective of the unlike populations used to derive the predictive equations, rather than attributes of the test subject. Thus, while the absolute body fat level may be uncertain, these devices can track changes in the level over time.
The majority methodologies are derived from a relatively normal population who in general has not used steroids. Since testosterone influences muscle versus fat partitioning, pharmacologic levels of testosterone allow for lower body fat levels than achievable with physiologic levels of testosterone.
To conclude, even for those individuals who achieve ultra-low body fat percentages, that level is rarely maintained for periods longer than the time required for a contest or photoshoot to occur. Long term maintenance of ultra-low body levels is simply not feasible for most people.