The Accuracy Of Selected Field Measures For Predicting Body Fat Percentage In Female Athletes

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There are numerous techniques that measure body fat percentage (BF%), and recently dual-energy x-ray absorptiometry (DEXA) has emerged as the criterion method for assessing body fat percentage in laboratory settings. However, most athletes do not have access to DEXA technology. Bioelectrical impedance analysis (BIA) and the skinfold technique (SF) are two popular field techniques that can predict BF% in field settings. There is limited research available that has cross-validated these measures in female athletes using DEXA. PURPOSE: The purpose of this investigation was to determine the accuracy of BIA and SF for estimating body fat percentage (BF%) in college-age female athletes using DEXA as the criterion method. METHODS: Forty female athletes from the National Association for Intercollegiate Athletics (NAIA) volunteered to participate in this study. For each participant, BF% was obtained via DEXA, hand-to-hand BIA, and a popular SF model (Jackson et al., 1980). The mean predicted BF% value by BIA and SF were compared to the criterion DEXA measure. RESULTS: The DEXA strongly correlated to the BIA (r=0.74, p<0.01) and SF (r=0.85, p<0.01). The mean values for each of the BF% techniques were as follows: DEXA = 27.6 ± 5.3%, BIA = 22.5 ± 3.5%, and the SF = 19.9 ± 4.2%. Bland-Altman Plots showed that the mean difference between the criterion and predicted values was -5.1% for BIA and -7.7% for SF. Furthermore, the 1.96 SD of the differences ranged from -12.3% to 2.1% for BIA and -2.1% to -13.3% for SF. Last, the standard error of estimate was 3.6% for BIA and 2.8% for SF. CONCLUSIONS: The results of this investigation indicate that BIA and SF significantly underestimated BF% in female athletes when compared to the criterion DEXA. There also appears to be large individual differences in the criterion vs. predicted BF% values. Therefore, it appears that BIA and SF techniques are not valid field measures, when compared to the DEXA, for estimating BF% in female athletes. Inaccurate body composition estimates could have consequences well worth noting, such as prompting body image concerns and/or misclassifying an athlete with an acceptable body fat category as over or underweight.