Foot-to-Foot Bioelectrical Impedance, Air Displacement Plethysmography, and Dual Energy X-ray Absorptiometry in Resistance-Trained Men and Women

摘要

International Journal of Exercise Science 11(4): 1145-1155, 2018. Accurate assessment of body composition is important to athletic performance goal setting and nutritional program design. Dual-energy x-ray absorptiometry (DXA) is considered the “gold standard” in body composition assessment, yet the cost renders DXA unfeasible for many. Therefore, it is of interest to compare other body composition assessment methods to DXA in resistance-trained individuals whose focus is athletic performance. The purpose of the current study was to determine the agreement in estimates of body composition ((body fat (BF%); fat mass (FM); fat free mass (FFM)) by bioelectrical impedance analysis (BIA; Tanita SC-331S) and air displacement plethysmography (ADP; BODPOD) compared to DXA (Hologic Horizon A) in 31 resistance-trained adults (men=15, women=16; mean±SD: 23.6±4.7years). Differences were found in BF% and FM between BIA and DXA. Regression analysis showed BF% and BMI to explain 24% and 29.9% of the variance in BF% measurements between DXA and BIA, respectively. The results of the Bland-Altman plot indicate a poor level of agreement between BIA and DXA for BF%, FM, and FFM (-4.56±8.82 %, -3.48±7.04 kg, 4.59±7.33 kg, respectively). ADP had wide limits of agreement for all variables (BF: 1.85±4.83 %, FM: 1.54±3.72 kg, FFM:-0.22±4.15 kg). BIA and ADP showed increasing variance in all measures as levels of fatness increased, with the exception of FFM for ADP. Compared to DXA, BIA overestimated BF% and FM, and underestimated FFM. Although wide individual errors were noted, no differences were found between ADP and DXA. The magnitude of inaccuracies between methods may be dependent upon individual body fatness.