RESUMEN
To describe the occurrence of near-to-maximal sprinting speed (near-to-MSS) running bouts during training and hamstring injuries during the consecutive match of the same turnaround in elite football (soccer). Retrospective data from 36 team-seasons (16 elite teams performing in top European leagues) were analyzed (627 players, 96 non-contact time loss match hamstring injuries). We described 1) the occurrence of > 85%, > 90% or > 95% MSS exposures during training within each turnaround and match hamstring injuries and 2) whether the above-mentioned injury occurrences differed depending on the day(s) of the turnarounds (i.e., the period separating two consecutive matches, which is generally from 3 to 8 days) when these speed exposures occurred. The longer the length of the turnarounds and the lower the speed thresholds, the greater the number (and proportion) of near-to-MSS exposures (e.g., 18%, 45% and 72% of turnarounds with > 85% runs for 3, 5 and 7-turnarounds, respectively). For half of the turnarounds examined, there were no match hamstring injuries when players were exposed to running bouts > 95% MSS during training (e.g., injury rates: 0; CI: 0-15). Injuries still occurred during 85% of the turnarounds when there were no or lower relative speed exposures (i.e., > 85 or > 90%, injury rates: 2-5, CI: 0-6). Finally, irrespective of the turnaround length, there were no match hamstring injuries when > 95% MSS exposures occurred at D-2, while in contrast, injuries still happened when players were not exposed at all, or when these exposures occurred at D-3 and/or earlier within the turnaround. While the present observational study design precludes the examination of causal relationships, the programming of > 95% MSS exposures at D-2 may help mitigate match hamstring injury occurrences in elite football.
RESUMEN
PURPOSE: To examine the association between the programming of days off (ie, no pitch training, days off feet) within turnarounds of varying length and injury rate in elite soccer. METHODS: Retrospective data from 56 team seasons of players belonging to 18 elite teams performing in top leagues including the English Premier League, Italian Serie A, Bundesliga, Scottish Premiership, Major League Soccer, and the Dutch Eredivisie from January 2018 to December 2021 were analyzed (total of 1578 players, 2865 injuries, 2859 noninternational matches, and 12,939 training-session days). The turnarounds examined lasted from 3 to 8 days. Only injuries with ≥3-day time loss were retained for analysis. The authors then looked at the injury rate within each microcycle in relation to the presence of a day off or not and its programming sequences in relation to the previous match (ie, day off at D + 1 vs D + 2 for the day after the match or the following, respectively). RESULTS: During 3- and 7-day turnarounds, the sequences including the day off feet at D + 2 were associated with 2 to 3 times lower overall noncontact injury rates than the other programming sequences (Cohen d: 0.9-2.7). For the other turnarounds, the differences between the sequences were unclear. CONCLUSION: The programming of a day off (or at least "off feet") at D + 2 may be associated with moderately to largely lower incidence of noncontact injuries, especially during 3- and 7-day turnarounds.