Influence of playing standard and physical fitness on activity profiles and post-match fatigue during intensified junior rugby league competition

Influence of playing standard and physical fitness on activity profiles and post-match fatigue during intensified junior rugby league competition

BACKGROUND: The aim of this study was to determine whether the fatigue responses to the same intensified rugby league competition differed depending on playing standard and physical fitness.

METHODS: Players from a high-standard (n = 15) and a low-standard (n = 16) junior rugby league team had lower body neuromuscular fatigue, perceptual wellbeing, and blood creatine kinase (CK) assessed over an intensified competition. Global positioning system units measured match activity profiles and rating of perceived exertion-assessed internal loads. Players were divided into high- and low-fitness groups across the two standards based on Yo-Yo intermittent recovery test performance.

RESULTS: Playing intensity increased with playing standard and fitness levels (high-standard = 92 +/- 6 m.min(-1) vs. 88 +/- 6 m.min(-1); low-standard = 88 +/- 2 m.min(-1) vs. 83 +/- 6 m.min(-1)). Despite greater internal and external loads, high-fitness players showed smaller reductions in lower body power (high-standard effect size [ES] = -0.74; low-standard ES = -0.41). High-standard players had smaller increases in blood CK (77% +/- 94% vs. 113% +/- 81%; ES = -0.41), primarily due to very small increases in the high-fitness group (50% +/- 45%).

CONCLUSIONS: Increased fitness leads to greater internal and external workloads during intensified competition, smaller increases in blood CK, and less neuromuscular fatigue. Maximising player fitness should be a primary goal of coaches in order to increase match workloads and reduce post-match fatigue during intensified competition.

KEY POINTS: Increased physical fitness results in greater relative and absolute match workloads.Increased physical fitness results in less fatigue and muscle damage during an intensified competition.Coaching staff should aim to maximise physical fitness in order to optimise match performance and reduce player fatigue.

© 2015 Johnston et al.; licensee Springer. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.