Validity of Bioimpedance as a Measure of Body Fat in High School Wrestlers

Abstract

Background: In recent years several state high school athletic association have investigated methods to ensure the health and safety of high school wrestlers. One method implemented by the National Collegiate Athletic Association requires the prediction of minimum weight (MW) prior to the competition season. This weight certification program requires the assessment of body composition and hydration status. Results from those assessments place wrestlers in their lowest allowable wrestling weight class. There are a variety of measurement devises that have proven to be effective in measuring body composition. However, several considerations must be taken into account when choosing a devise such as affordability and reliability. Of those devices leg-to-leg bioelectrical impedance analysis (BIA) has been suggested for use with wrestlers.

Purpose: To test the validity of bioelectrical impedance as an instrument of body composition and minimum wrestling weight compared to three-site skinfold using the Lohman-Brozek formula and the Bod Pod®; among hydrated high school wrestlers.

Methods: Criterion for this study was the Bod Pod®. Subjects included 98 high school wrestlers taking part in the pre-season wrestling weight certification program implemented by the Virginia High School League. Hydration was assessed and a urine specific gravity (USG) ≤ 1.020 was assigned as the level of hydration.

Results: In order to investigate the validity of BIA in this study a repeated measure ANOVA with between-subjects factors was used to assess the equality of means between the three measurement devices. Also, in order to investigate hydration affect subjects were divided into two categories (hydrated and dehydrated). Finally, prior to analysis subjects were placed in weight categories based on their assigned wrestling weight class. Results of this study demonstrated that the three measurement devices did not produce similar results and it was concluded that hydration level had no affect on the measurements. Therefore, at this time BIA should not be considered as an alternative method for assessing body composition in high school wrestling weight certification programs.