Influence of Maturation Status on Eccentric Hamstring Strength Improvements in Youth Male Soccer Players following the Nordic Hamstring Exercise

Purpose: This study examined the effects of a 6-week nordic hamstring exercise (NHE) program in youth male soccer players of less mature (Pre-Peak Height Velocity [PHV]) or more mature (Mid/Post-PHV) status. Methods: Forty-eight participants were separated into Pre-PHV (11.0 ± 0.9yrs) or Mid/Post-PHV (13.9 ± 1.1) groups and further divided into experimental (EXP) and control (CON) groups with eccentric hamstring strength assessed (Nordbord) both pre and post the training program. Participants in the EXP groups completed a periodised NHE program performed once or twice weekly over a 6-week period. Results: The NHE programme resulted in moderate and small increases in relative eccentric hamstring strength (N.kg-1) in the Pre-PHV EXP (d = 0.83 [0.03 - 1.68]) and Mid-PHV EXP (d = 0.53 [-0.06 - 1.12]) groups respectively. Moderate increases in the same measure were also seen in the between-group analyses in the Pre-PHV (d = 1.03 [0.23 - 1.84]) and Mid-PHV groups (d = 0.87 [0.22 - 1.51]), with a greater effect observed in the former. Conclusion: The results from this study demonstrate that a 6-week NHE program can improve eccentric hamstring strength in male youth soccer players with less mature players achieving mostly greater benefits. The findings from this study can aid in the training prescription of the NHE in youth male soccer players.