Abstract
BACKGROUND
Professional rugby union is a high-intensity contact sport with position-specific high training and match volumes across a season that may lead to periods of fatigue if above a typically experienced threshold. This study assesses the influence of match play and/or training on fatigue levels in rugby union players.
OBJECTIVE
We aimed to perform a systematic review and meta-analysis of measures used to assess fatigue status in male professional rugby union players.
METHODS
Using electronic databases (PubMed, SPORTDiscus, Web of Science, Cochrane Library, EMBASE, and MEDLINE), a systematic review of fatigue testing in rugby union was conducted on (1) neuromuscular, (2) subjective self-report, (3) biochemical, and (4) heart rate-derived measures.
RESULTS
Thirty-seven articles were included in this systematic review, of which 14 were further included in a meta-analysis. The results of the meta-analysis revealed small, yet not significant, decreases in countermovement jump height immediately after (effect size [ES] = - 0.29; 95% confidence interval [CI] - 0.64 to 0.06), 24 h (ES = - 0.43; 95% CI - 3.99 to 3.21), and 48 h (ES = - 0.22; 95% CI - 0.47 to 0.02) after exposure to rugby union match play or training. Reported wellness (ES = - 0.33; 95% CI - 1.70 to 1.04) and tiredness (ES = - 0.14; 95% CI - 1.30 to 1.03) declined over a period of a few weeks (however, the results were not-statistically significant), meanwhile muscle soreness increased (ES = 0.91; 95% CI 0.06 to 1.75) within the 96 h after the exposure to rugby union match play or training. Finally, while cortisol levels (ES = 1.87; 95% CI - 1.54 to 5.29) increased, testosterone declined (ES = - 1.54; 95% CI - 7.16 to 4.08) within the 24 h after the exposure. However, these results were not statistically significant.
CONCLUSIONS
Subjective measures of muscle soreness can be used to assess fatigue after match play and training in rugby union players. Within-study and between-study variability for countermovement jump height, biochemical markers, and heart rate-derived measures means the utility (practical application) of these measures to assess fatigue in professional rugby union players after matches and training is unclear.
CLINICAL TRIAL REGISTRATION
PROSPERO ID: CRD42020216706.
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