A FOUR-WEEK TRAINING PROGRAM WITH THE NORDIC HAMSTRING EXERCISE DURING PRESEASON INCREASES ECCENTRIC STRENGTH OF MALE SOCCER PLAYERS

Abstract

The Nordic hamstring exercise (NHE) is an effective strategy to prevent hamstring strain injuries in soccer players. The current literature recommends a 10-week training program with three sessions per week, but the short preseason period and the congested schedule make difficult for high-performance soccer teams to apply the NHE as recommended. The purpose of this study was to examine the effect of a pragmatic NHE training program during a four-week preseason period on eccentric knee flexor strength of high-performance soccer players. Quasi-experimental clinical trial. This study included 25 under-20 male soccer players from a premier league club. They performed eight sessions of NHE (3 sets of 6-10 repetitions, twice a week) during the four-week preseason period. The eccentric knee flexor strength was evaluated during the NHE execution on a custom-made device, before and after the training program. The NHE training program significantly increased the players' eccentric knee flexor strength in both right (Δ = 13%; p<0.001; effect size = 0.97) and left limbs (Δ = 13%; p<0.001; effect size = 0.92). Individual analysis identified 76% of the players as responders to the NHE training program (Δ = 16%; effect size = 1.60), and 24% as non-responders (Δ = 3%; effect size = 0.24). A four-week training program with NHE performed twice a week is feasible in the real-world of high-performance soccer clubs and increases the eccentric knee flexor strength of male soccer players.