Hamstring Injury Prevention in Soccer: Before or After Training?

Hamstring muscle strains account for 12-16% of all injuries sustained in professional soccer, and almost half (47%) of all hamstring strains occur during the last third of the 1st and 2nd halves of soccer matches. Muscle fatigue is therefore considered an aetiological risk factor, and injury prevention programs such as the FIFA 11+ are administered during the warm-up before training. Nordic Hamstring exercises (NHE) are part of the FIFA 11+ program and they have been shown to increase eccentric hamstring strength and reduce the injury risk to players, but the optimal scheduling of NHE relative to soccer training sessions is unknown. We hypothesized that the adaptation to strengthening exercises may be optimized when performed in a “fatigued” state, after a soccer training session. Therefore, in this research program we undertook two separate studies to examine the acute responses and chronic adaptations to performing NHE’s either before or after soccer training sessions. In the first study, 8 amateur players attended the laboratory on two separate occasions and performed a 60-min simulated soccer training session. Players performed a program of NHE (6 sets of 5 repetitions) either before (PRE) or after (POST) training, in a randomized manner. The results from this study suggested that performing NHE prior to soccer training reduces eccentric hamstring strength and may increase the risk of muscular injury during the subsequent session. In the second study, amateur soccer players were randomized into 3 training groups for a 12-week intervention. The control group (CON; n=10) undertook core stability exercises, whereas a periodized NHE program was delivered either PRE (n=11) or POST (n=10) bi-weekly training sessions. In this study we concluded that a 12-week eccentric hamstring-strengthening program increased strength via changes in muscle architecture and morphology, and also increased hamstring flexibility in amateur soccer players. As eccentric hamstring strength and flexibility are modifiable risk factors, we would strongly recommend that coaches administer this exercise in field training sessions to lower the risk of hamstring injury strains. Although we did not see any differences between PRE and POST groups in the chronic intervention study, we would recommend that the NHE’s be performed at the end of training given our results from the first study.