Evaluation of Multifrequency Bioelectrical Impedance Analysis in Assessing Body Composition of Wrestlers

UTTER, A. C. and P. G. LAMBETH. Evaluation of Multifrequency Bioelectrical Impedance Analysis in Assessing Body Composition of Wrestlers. Med. Sci. Sports Exerc., Vol. 42, No. 2, pp. 361-367, 2010. Purpose: To evaluate the accuracy of multifrequency bioelectrical impedance analysis (MFBIA) in assessing fat-free mass (FFM) in comparison with hydrostatic weighing (HW) and skinfolds (SK) in high school wrestlers in a hydrated state. Methods: Body composition was determined by MFBIA, HW, and three-site SK in 72 high school wrestlers (mean +/- SD; age = 15.3 +/- 1.4 yr, height = 1.71 +/- 0.08 in, body mass = 67.3 +/- 13.4 kg). Hydration state was quantified by evaluating urine specific gravity. Results: There were no significant differences for estimated FFM between MFBIA (57.2 +/- 9.5 kg) and HW (57.0 +/- 10.1 kg) or SK (56.4 +/- 8.8 kg). The SEE for FFM with HW as the reference method were 2.73 kg for MFBIA and 2.66 kg for SK. Correlations were found for FFM between HW and MFBIA (r = 0.96, P < 0.001) and between HW and SK (r = 0.97, P < 0.001). A systematic bias was found for MFBIA because the difference between MFBIA and HW correlated with the FFM average of the two methods (r = -0.22, P < 0.001). A bias was also seen between SK and HW and correlated with the FFM average (r = -0.47, P < 0.001). Conclusions: This study demonstrates that MFBIA provides similar estimates of FFM when compared with HW in a heterogeneous high school wrestling population during a hydrated state. MFBIA is an attractive assessment tool, easy to use, and may be considered as an alternative field-based method of estimating the FFM of high school wrestlers.