Impact of neuromuscular fatigue on match exercise intensity and performance in elite australian football
Lippincott Williams & Wilkins
Faculty of Health, Engineering and Science
School of Exercise and Health Sciences
Mooney, MG, Cormack, S, O'Brien, BJ, Morgan, WM, and McGuigan, M. Impact of neuromuscular fatigue on match exercise intensity and performance in elite Australian football. J Strength Cond Res 27(1): 166-173, 2013-This study aimed to quantify the influence of neuromuscular fatigue (NMF) via flight time to contraction time ratio (FT:CT) obtained from a countermovement jump (CMJ) on the relationships between yo-yo intermittent recovery (level 2) test (yo-yo IR2), match exercise intensity (high-intensity running [HIR] m.min21 and Load.min21) and Australian football (AF) performance. Thirtyseven data sets were collected from 17 different players across 22 elite AF matches. Each data set comprised an athlete's yoyo IR2 score before the start of the season, match exercise intensity via global positioning system and on-field performance rated by coaches' votes and number of ball disposals. Each data set was categorized as normal (.92% baseline FT:CT, n = 20) or fatigued (,92% baseline FT:CT, n = 17) from a single CMJ performed 96 hours after the previous match. Moderationmediation analysis was completed with yo-yo IR2 (independent variable), match exercise intensity (mediator), and AF performance (dependent variable) with NMF status as the conditional variable. Isolated interactions between variables were analyzed by Pearson's correlation and effect size statistics. The Yo-yo IR2 score showed an indirect influence on the number of ball disposals via HIR m.min21 regardless of NMF status (normal FT:CT indirect effect = 0.019, p < 0.1, reduced FT:CT indirect effect = 0.022, p < 0.1). However, the yo-yo IR2 score only influenced coaches' votes via Loadmin21 in the nonfatigued state (normal: FT:CT indirect effect = 0.007, p ,0.1, reduced: FT:CT indirect effect = 20.001, p . 0.1). In isolation, NMF status also reduces relationships between yo-yo IR2 and load.min21, yo-yo IR2 and coaches votes, Load.min21 and coaches' votes (Δr . 0.1). Routinely testing yo-yo IR2 capacity, NMF via FT:CT and monitoring Load.min21 in conjunction with HIR m.min21 as exercise intensity measures in elite AF is recommended.