Reliability of Bioelectrical Impedance Analysis to Track Off-Season Body Composition Changes in Division III Football Athletes

Abstract

This study examined the reliability of bioelectrical impedance analysis (BIA) compared to dual-energy x-ray absorptiometry (DEXA) to track body composition changes in Division III football athletes across an entire off-season training program. A sample of Division III male college football athletes (n=32) participated in this study. Total body composition analysis was measured using DEXA and BIA at three time points throughout the off-season training program. These time points represented the beginning (January), middle (May), and end (August) of the off-season training program. Change scores (post-pre) were calculated between time points to quantify changes across time points. Paired-samples t-tests were employed to examine any significant differences (p<0.05) between DEXA and BIA. Intraclass correlation coefficients (ICC) were used to examine agreement between methods across time. There were no significant differences (p>0.05) in FM, FFM, and FFMI changes between DEXA and BIA within the January-May time frame. A significant difference (p<0.05) between DEXA and BIA was detected in FM, FFM, and FFMI changes in the May-August time points. BIA showed an acceptable level of reliability in tracking early off-season changes in body composition compared to DEXA, however, the BIA significantly underestimated changes in FM and overestimated changes in FFM during late off-season programming.