Influence of physical qualities on post-match fatigue in rugby league players

Objectives: This study examined the influence of physical qualities on markers of fatigue and muscle damage following rugby league match-play. Design: Between subjects design. Methods: Twenty-one male youth rugby league players (age 19.2 ± 0.7 years; height 180.7 ± 5.6 cm; body mass 89.9 ± 10.0 kg) participated in the study. Yo-Yo intermittent recovery test (level 1), 3 repetition maximum back squat and bench press were assessed prior to 2 competitive fixtures. Neuromuscular fatigue (countermovement jump [CMJ] and plyometric push-up [PP]), and blood creatine kinase (CK) were assessed before and after match-play. During match-play, movements were recorded using microtechnology. Players were divided into high- and low-groups based on physical qualities. Results: High Yo-Yo and squat performance resulted in greater loads during match-play (p < 0.05). There were larger reductions in CMJ power in the low Yo-Yo group at both 24 (ES = -1.83), and 48 h post-match (ES = -1.33). Despite greater internal and external match loads, changes in CMJ power were similar between squat groups. There were larger increases in blood CK in the low Yo-Yo group at 24 (73% vs. 176%; ES = 1.50) and 48 h post-match (28% vs. 80%; ES = 1.22). Despite greater contact loads, the high squat group exhibited smaller changes in blood CK post-match (ES = 0.25-0.39). Conclusions: Post-match fatigue is lower in players with well-developed high-intensity running ability, and lower body strength, despite these players having greater internal and external match loads