Changes in markers of fatigue following a competitive match in elite academy rugby union players

Abstract

Background: Post-match fatigue has yet to be investigated in academy rugby union players.
Objectives: To determine the magnitude of change in upper-(plyometric push-up (PP) flight-time) and lower-body (countermovement jump (CMJ) mean power) neuromuscular function (NMF), whole blood creatine kinase (CK) and perception
of well-being following a competitive match in academy rugby union players.
Methods: Fourteen academy rugby union players participated in the study. Measures were taken 2 h pre-match (baseline) and immediately post-match. Further testing was also undertaken at 24-, 48- and 72 h respectively post-match. Changes in measures from baseline were determined using magnitude-based inferences.
Results: Decreases in CMJ mean power were likely substantial immediately (-5.5±3.3%) post-match, very likely at 24 h (-7±3.9), likely at 48 h (-5.8±5.4), while likely trivial at 72 h (-0.8±3.8) post-match. PP flight-time was very likely reduced immediately (-15.3±7.3%) and 24 h (-11.5±5.7%) post-match, while possibly increased at 48 h (3.5±6.0%) and likely trivial at 72 h (-0.9±5.4%) post-match. Decreases in perception of well-being were almost certainly substantial at 24 h (-24.0±4.3%), very likely at 48 h (-8.3±5.9%), and likely substantial at 72 h (-3.6±3.7%) post-match. Increases in CK were almost certainly substantial immediately (138.5±33%), 24 h (326±78%) and 48 h (176±62%) post-match, while very likely substantial at 72 h (57±35%) post-match.
Conclusion: These findings demonstrate the transient and multidimensional nature of post-match fatigue in academy rugby union players. Furthermore, the results demonstrate the individual nature of recovery, with many players demonstrating different recovery profiles from the group average.

Keywords: collision sport, monitoring, sports injuries