Comparison of total and segmental body composition using DXA and multifrequency bioimpedance in collegiate female athletes

Esco, MR, Snarr, RL, Leatherwood, MD, Chamberlain, NA, Redding, ML, Flatt, AA, Moon, JR, and Williford, HN. Comparison of total and segmental body composition using DXA and multifrequency bioimpedance in collegiate female athletes. J Strength Cond Res 29(4): 918-925, 2015 - The purpose of this investigation was to determine the agreement between multifrequency bioelectrical impedance analysis (BIA) and dual-energy x-ray absorptiometry (DXA) for measuring body fat percentage (BF%), fat-free mass (FFM), and total body and segmental lean soft tissue (LST) in collegiate female athletes. Forty-five female athletes (age 21.2 ± 2.0 years, height 166.1 ± 7.1 cm, weight 62.6 ± 9.9 kg) participated in this study. Variables measured through BIA and DXA were as follows: BF%, FFM, and LST of the arms (ARMS LST), the legs (LEGS LST), the trunk (TRUNK LST), and the total body (TOTAL LST). Compared with the DXA, the InBody 720 provided significantly lower values for BF% (-3.3%, p < 0.001) and significantly higher values for FFM (2.1 kg, p < 0.001) with limits of agreement (1.96 SD of the mean difference) of ±5.6% for BF% and ±3.7 kg for FFM. No significant differences (p < 0.008) existed between the 2 devices (InBody 720 - DXA) for ARMS LST (0.05 kg), TRUNK LST (0.14 kg), LEGS LST (-0.4 kg), and TOTAL LST (-0.21 kg). The limits of agreement were ±0.79 kg for ARMS LST, ±2.62 kg for LEGS LST, ±3.18 kg for TRUNK LST, and ±4.23 kg for TOTAL LST. This study found discrepancies in BF% and FFM between the 2 devices. However, the InBody 720 and DXA appeared to provide excellent agreement for measuring total body and segmental LST. Therefore, the InBody 720 may be a rapid noninvasive method to assess LST in female athletes when DXA is not available.