Improving Body Composition Analysis in Collegiate Athletes

Abstract

Body composition is a critical metric used by practitioners to establish athlete health, training goals, nutrition plans, and performance potential. Two common laboratory methods of body composition assessment include air displacement plethysmography (ADP) and dual-energy x-ray absorptiometry (DXA). DXA is the gold standard method as it utilizes a 3-compartment model, enabling practitioners and researchers to obtain lean mass, fat mass, and bone mass. However, due to cost and state-by-state regulations regarding who can operate DXA, many programs may not find it feasible. ADP is a more cost effective and simpler method of measuring body composition. It has been shown to be a valid and reliable alternative to DXA. As a result, practitioners and researchers may find ADP more feasible than DXA. However, ADP is unable to measure bone mineral density (BMD) and conflicting evidence has been reported regarding its validity in an athletic population. Inaccuracies in body composition measurements may lead to inappropriate nutrition and training programs, which may cause an athlete to gain or lose unnecessary fat mass or fat free mass, respectively. This inappropriate change in body composition may lead to musculoskeletal injuries and hinder athletic performance. Therefore, the purpose of this dissertation is to improve upon the utility of ADP use in an athletic population through, 1) understanding how body composition values derived from ADP may influence BMD, 2) evaluating the influence of individual characteristics upon the difference in percent body fat (%BF) between ADP and DXA, and 3) developing a two- compartment model estimation equation to obtain more accurate %BF results from ADP in an athletic population.