RESISTANCE TRAINING CARRIED OUT BEFORE PRACTICE COMPROMISES THE PERFORMANCE OF SEVERAL HIGH VELOCITY TASKS IN SOCCER GOALKEEPERS

Abstract

This study aimed to elucidate whether the performance of high-velocity soccer-related tasks is compromised immediately after completing squat-based resistance training sessions differing in the level of effort. Eleven young male soccer goalkeepers (age: 17.1±1.7 years) completed four testing sessions. The parallel back-squat one-repetition maximum (1RM) was determined in the first session. The remaining sessions were applied in a counterbalanced order and they consisted of the assessment of four high-velocity soccer-related tasks (countermovement jump [CMJ], horizontal jump, soccer kicking, and soccer throwing) at rest (control protocol) and immediately after completing four sets of the squat exercise against the 60%1RM until reaching a velocity loss of 15% (low-effort protocol) and 30% (moderate-effort protocol). The mean velocity of the fastest repetition did not differ between the protocols (≈ 0.80 m·s^-1; p=.447), whereas the number of repetitions was greater for the moderate-effort (18.2±5.3 repetitions) compared to the low-effort (10.1±4.5 repetitions) protocol (p<.001). The protocols were ranked according to the magnitude of the dependent variables as follows: CMJ height (control > low-effort = moderate-effort), horizontal jump distance (control > low-effort > moderate-effort), kicking ball distance (low-effort = control = moderate-effort), and throwing ball distance (control = low-effort = moderate-effort). These results indicate that squat-based RT sessions compromise the performance of some high-velocity tasks (vertical and horizontal jumps) but not others (kicking and throwing), whereas a greater level of effort (i.e., velocity loss) only induced larger reductions in the performance of the horizontal jump distance.

Keywords: football, jump, kicking, squat, throwing, velocity-based training