EFFECT OF TIMING OF ECCENTRIC HAMSTRING STRENGTHENING EXERCISES DURING SOCCER TRAINING: IMPLICATIONS FOR MUSCLE FATIGABILITY

摘要

The purpose of this study was to examine the effects of a field-based injury prevention exercise on eccentric hamstring strength during simulated soccer match play. Sixteen semiprofessional soccer players (age 21.3 ± 2.9 years; height 185.0 ± 8.7 cm; body mass 81.6 ± 6.7 kg) completed the Soccer-specific Aerobic Field Test (SAFT^sup 90^), a multidirectional 90-minute exercise protocol representative of soccer match play. Subjects performed 3 maximal dominant-limb isokinetic contractions at 120° *s^sup -1^ for concentric knee extensors (conQ) and flexors (conH), and eccentric knee flexors (eccH) before SAFT^sup 90^ (t^sub 0^), at half-time (t^sub 45^), and immediately after the SAFT^sup 90^ (t^sub 105^). After baseline testing, subjects were divided into 2 groups, either performing Nordic hamstring eccentric strengthening exercises during the cool-down (CD) or warm-up (WU) of twice-weekly training sessions. After an 8-week intervention program, the baseline testing was repeated. The WU group displayed a significant increase postintervention in eccH gravity-corrected peak torque (PT) and the functional eccH:conQ ratio at t^sub 0^ (p < 0.01), a significantly greater improvement compared with CD group (p < 0.05). Conversely, the CD group displayed a significant increase in both eccH PT and the functional eccH:conQ ratio postintervention at t^sub 45^ (p < 0.05) and at t^sub 105^ (p < 0.05), which were significantly greater increases compared with the WU group (p < 0.05). These findings indicate that the training intervention had a time-dependent beneficial effect on eccentric hamstring strength and that strength training conducted posttraining significantly reduced the negative influence of fatigue. [PUBLICATION ABSTRACT]