Comparing Estimates Of Adipose And Skeletal Muscle Massbetween Bodpod And Dexa In Collegiate Athletes

Accurately estimating skeletal muscle (SKM) and fat masses (FM) in athletes is crucial for effectively designing sport training programs. Recently, air displacement plethysmography (ADP) gained popularity in sport programs for measuring body composition (BC). A significant limitation of ADP is the reliance on a two-compartment model, measuring only FM and fat-free mass (FFM), potentially leading to misestimations in BC most concerningly, SKM. Dual-energy x-ray absorptiometry (DEXA) remains the gold-standard for quantifying BC however, is underutilized in athletes. PURPOSE: To compare estimations in FFM and FM between ADP and DEXA methods in a sample of male and female collegiate athletes. METHODS: In total, 67 (males = 49, females = 18) athletes aged 17 to 22 years playing baseball, basketball, American football or soccer participated in the study. All athletes, in their respective off-seasons, underwent two, sequential BC tests, BodPod (ADP) and DEXA. Athletes followed all pre-testing guidelines and were tested in the morning. The BodPod quantified FFM and FM using sex-, age- and sport-specific predictive equations while the DEXA directly estimated FFM (∑bone mineral content and SKM) and FM. Differences in the estimates of FFM and FM masses between DEXA and BodPod were compared via studentized paired samples t-test. RESULTS: Statistically significant differences in FFM and FM between DEXA and BodPod assessments were observed. Specifically, the BodPod significantly overestimated FFM (-6.2 ± 2.2 kg, 95%CI: -6.8, -5.7, p < 0.001) and underestimated FM (+5.1 ± 2.1 kg, 95%CI: 4.5, 5.6, p < 0.01) compared to the DEXA (FFM: 7.3 kg vs 6.7 kg and FM: 14.5 kg vs 19.6 kg, respectively). Similarly, the BodPod significantly underestimated %FM (+6.3 ± 2.7%, 95%CI: 5.6, 6.9, p < 0.001) relative to the DEXA (16.6% vs 22.9%). The observed misestimations were consistent for male and female athletes. CONCLUSION: ADP significantly overestimated FFM and underestimated FM and %FM in our sample of collegiate athletes. SIGNIFICANCE/NOVELTY: Misestimating BC poses significant challenges in enhancing sport performance. Coaches heavily rely on body composition data for evaluating effectiveness of training programs and player performance, emphasizing the importance of utilizing gold-standard methodologies, like DEXA.