Document Type



Reactive strength represents the ability to change rapidly from eccentric to concentric contraction and may be influenced by body composition. The purpose of the study was to determine if body mass (BM), lean body mass (LBM), or percent fat mass (%FM) were associated with reactive strength. Twenty-five males undergoing training for the National Football League’s combine had their Reactive Strength Index (RSI) measured from a 4-jump drop jump (DJ) onto an electronic timing mat, and BM, LBM and %FM assessed via a BodPod. Pearson correlation coefficients showed moderate, negative significant correlations between RSI and BM (r(23)=-.531, p=.006), and RSI and LBM (r(23)=-.565, p=.003). RSI was not associated with %FM. Explosiveness appears related to heaviness but not fatness. Coaches may consider effects of body composition modulation on RSI.