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Acute effects of aerobic activity, static stretching, and explosive exercises on muscular performance and range of motion of young soccer players

The current study aims to investigate the acute effects of light aerobic activity, static stretching (SS), strengthening and explosive exercises on lower-body muscular performance and range of motion (ROM). Dose-response effect of SS on performance and ROM was also studied. Nineteen young male soccer players (age: 13.9 ± 0.46 years) participated in a cross-over randomized trial. Participants performed 5-minute aerobic activity, followed by seven bouts of SS of calf, quadriceps, adductor and hamstring muscles lasting 20 seconds each. Additionally, two sets of strengthening and explosive exercises were performed after SS in the experimental condition. Power and strength were assessed by counter-movement jump (CMJ) and maximal voluntary contraction of hip adductors, while 3 flexibility tests were used for assessing ROM of lower body. Repeated-measures ANOVA revealed an increase in CMJ performance after aerobic activity, followed by a decrease after SS in a dose-dependent manner that continued to be present 15 minutes post-SS. Strengthening and explosive exercises did not neutralize the acute negative effects of SS on CMJ performance. No significant acute effect of selected interventions on maximal and explosive strength of hip adductors was observed. Finally, sit-and-reach and hip abduction ROM increased after aerobic activity and continued to increase throughout the SS protocol, and was preserved 15 minutes post-SS. Our results confirm that SS can impair lower-body power in young soccer players, and that these negative effects last at least 15 minutes. Excessive use of SS, as performed in this study, should be avoided during warm-up of young soccer players.