Muscle injury rate in professional football is higher in matches played within 5 days since the previous match: a 14-year prospective study with more than 130 000 match observations

BACKGROUND: The association between match congestion and injury rates in professional football has yielded conflicting results. AIM: To analyse associations between match congestion on an individual player level and injury rates during professional football matches. METHODS: Data from a prospective cohort study of professional football with 133 170 match observations were analysed with Poisson regressions. Associations between short-term match congestion, defined as number of days between two match exposures (≤3, 4, 5, 6 and 7-10 days) and injury rates were analysed. To analyse the influence of long-term match congestion, defined as individual match exposure hours in the 30 days preceding a match, observations were categorised into three groups (low, ≤4.5; medium, >4.5 to ≤7.5; and high, >7.5 hours). RESULTS: No differences in total match injury rates were found between the reference category (≤3 days) and the other categories of short-term congestion. Muscle injury rates were significantly lower in matches preceded by 6 (rate ratio (RR) 0.79; 95% CI 0.65 to 0.95) or 7-10 days (RR 0.81; 95% CI 0.71 to 0.93) compared with ≤3 days since the last match exposure. No differences in total and muscle injury rates between the three long-term match congestion groups were found. CONCLUSIONS: In this study of male professional football players, there were no match congestion-related differences in total match injury rates, but muscle injury rates during matches were lower when players were given at least 6 days between their match exposures.