Body CompositionComparisonsVia Dual Energy X-Ray Absorptiometry and Air Displacement Plethysmography in College Athletes

Abstract

Body composition is a highly important metric in regards to overall physical activity as well as sports performance. Most body fat percentage (BF%) measurements are recorded using two-compartment models, such as skinfold analyses, bioelectrical impedance analysis, or more accurately, via hydrostatic weighing or air displacement plethysmography (ADP). However, research has suggested that three-compartment models, like dual energy x-ray absorptiometry (DEXA), may provide more accurate recordings of BF%. However, limited research exists in comparing BF% obtained via two- and three-compartment models in collegiate athletes. PURPOSE: To compare BF% recordings via DEXA and ADP in Division-I collegiate male and female athletes. METHODS: Seventy-eight athletes (Male: n = 45 [age = 18.4 ± 1.0 y, height = 161.9 ± 55.5 cm, weight = 77.3 ± 32.5 kg]; Female: n = 33 [age = 18.0 ± 0.7 y, height = 146.3 ± 56.9 cm, weight = 55.9 ± 23.8 kg]) from multiple sports underwent BF% testing via DEXA and ADP. Both tests were completed on the same visit under supervision by the same test administrator. Hydration status was measured before testing to ensure that all athletes were properly hydrated prior to the test. Athletes were instructed to dress in accordance to the recommended protocols for both tests. Individual paired sample t-tests were run for BF% comparisons for whole group, male athletes, and female athletes. RESULTS: A significant mean difference existed for all athletes between DEXA (21.6 ± 10.3%) and ADP (16.4 ± 9.2%) when comparing BF% (p < 0.01, ES = 0.53). When factored for gender, male BF% exhibited a significant mean difference between DEXA (16.3 ± 9.5%) and ADP (11.8 ± 8.0%) (p < 0.01, ES = 0.51). Additionally, a significant mean difference for BF% was found in the female athletes between DEXA (28.5 ± 6.6%) and ADP (22.2 ± 7.1%) (p < 0.01, ES = 0.92). CONCLUSION: These results, which are consistent with previous research, indicate significantly greater BF% values for DEXA when comparing athletic populations.