Neuromuscular, Endocrine, And Perceptual Recovery Following A Youth American Football Game

Abstract

PURPOSE: American football is a high-intensity intermittent sport consisting of various movements and repeated collisions which makes recovery from a game challenging to adequately prepare for the next competition. Therefore, the purpose of this study was to determine the time course of recovery assessed by neuromuscular function, salivary biomarkers, and perceptual fatigue following a youth American football game. METHODS: Thirteen male American football youth athletes were monitored for 7 days following a single football game. Baseline measures were taken at 28h pre-game for lower body neuromuscular function via countermovement jumps (CMJ) to determine peak power (PP), jump height (JH), flight time (FT), and takeoff velocity (TOV). Saliva was analyzed for cortisol, testosterone, and C-reactive protein (CRP). Perceptual recovery was assessed by modified profile of mood states (POMS), perceived recovery status (PRS), and a daily wellness questionnaire consisting of four 10-point Likert scale questions examining stress, muscle soreness, sleep quality, and energy. These measures were repeated immediately post-game (30min), and at 20h, 44h, 68h, 92h, 116h, 140h post-game. RESULTS: Compared to baseline values there was a significant decrease (p<0.05) in CMJ PP, JH, TOV up to 68h post-game and FT 44h post-game. No significant difference existed among time points for salivary testosterone and CRP. Salivary cortisol concentration significantly increased following the game (baseline 0.12±0.09ug/dl, post-game 0.34±0.25ug/dl; p<0.05). Daily wellness ratings for energy were significantly decreased (baseline 7.2±1.6, post-game 4.7±2.4; p<0.05) while daily wellness ratings for soreness were significantly increased (baseline 4.6±2.6, post-game 6.3±1.3 (p<0.05) immediately following the game. POMS total mood disturbance, significantly increased (baseline -1.5±7.0, post-game 15.6±9.4; p<0.05) following the game. Athletes PRS exhibited a significant decrease in recovery up to 44h post-game (p<0.05), similar to the decrease in neuromuscular function. CONCLUSION: Neuromuscular function and PRS are impaired for up to 44-68h post-game. Coaches should consider the time course of post-game recovery when implementing practices and strength training to ensure adequate recovery from competition.