Comparison between traditional strength training and complex contrast training on repeated sprint ability and muscle architecture in elite soccer players.

The purpose of this study was to compare traditional strength training (TST) and complex contrast training (CCT) on the repeated-shuttle-sprint ability (RSSA), the countermovement squat jump (CMJ) height, the one repetition maximum (1RM) at squat on the Smith machine, and on muscle architecture in young, male elite soccer players.Twenty-two soccer players (mean age 18.4±0.4 years; mean weight 70.2±9.1 kg; mean height 179.9±7.5 cm) who belonged to the under-20 age group were randomly assigned into two groups: CCT (N.=10) or TST (N.=12). During the study period, the soccer players trained with CCT through power exercises performed before high-velocity exercises and TST based on a set-repetition format through daily, undulatory periodization.After statistical analysis (P<0.05), the results demonstrated that the specific CCT regimen provided a significant improvement in the RSSA percent decrement (moderate effect size), CMJ (large effect size) and 1RM ability (large effect size). However, the TST promoted significant changes in 1RM (large effect size) and a significant increase in the muscle thickness of the vastus intermedius (moderate effect size).The CCT protocol could be used to improve the RSSA parameters, CMJ and 1RM, and the TST developed dynamic strength and muscle growth. Coaches can choose either CCT or TST protocols according to the needs of their soccer players.