The Relationship Between Match-Play Characteristics of Elite Rugby League and Indirect Markers of Muscle Damage

Abstract

Purpose: Whilst exercise-induced muscle damage (EIMD) after a rugby league match has been well documented, the specific match actions that contribute to EIMD are unclear. Accordingly, the purpose of this study was to examine the relationship between the physical demands of elite rugby league matches and subsequent EIMD. Methods: Twenty-eight performances were captured using 10 Hz global positioning systems. Upper and lower body neuromuscular fatigue, creatine kinase (CK) and perceived muscle soreness were assessed 24 h before and at 12, 36 and 60 h after a competitive match. Results: High-intensity running was moderately higher in backs (6.6 ± 2.6 m•min-1) compared to forwards (5.1 ± 1.6 m•min-1), whereas total collisions were moderately lower (31.1 ± 13.1 cf. 54.1 ± 37.0). Duration (r = 0.9, CI: 0.77 to 0.96), total distance covered (r = 0.86, CI: 0.7 to 0.95) and distance covered over 18 km•h-1 (r = 0.76, CI: 0.51 to 0.91) were associated with increased CK concentration post-match. Total collisions and repeated high-intensity efforts (RHIE) were associated with large decrements in upper body neuromuscular performance (r = -0.48, CI: -0.74 to 0.02 and r = -0.49, CI: -0.77 to 0.05, respectively), muscle soreness (r = -0.68, CI: -0.87 to -0.1 and r = -0.66, CI: -0.89 to 0.21, respectively), and CK concentration (r = 0.67, CI: 0.42 to 0.85 and r = 0.73, CI: 0.51 to 0.87, respectively). Conclusion: Match duration, high-intensity running and collisions were associated with variations in EIMD markers, suggesting recovery is dependent on individual match demands.