Purpose: In soccer lower limb muscle strength and maximal running speed are considered decisive factors for performance (Bangsbo 1994). Strength training (ST) is a good means to improve them (Delecluse 1997). The question whether or not ST could be useful without any risk for young players remains (Archambault et al. 1995). This study examined the influence of a 3-week strength training programme (STP) on injuries, leg muscle strength and power, running speed, kicking performance and vertical jump of 24 soccer players, 17 yr. old, divided into a strength training (STG, n=12) and a control group (CG, n=12). Methods: STG and CG trained together 5 times a week (4 training sessions, plus an official match). For STG, STP consisted in 2 sessions per week, 1.5-h per session and concerned 4 muscle groups (knee extensors and flexors, hip flexors and foot extensors). For CG there was no STP. The training of each muscle group consisted in (1) a succession of heavy loads strength training in isometric, concentric and eccentric conditions (2) intense technical soccer sets of training. Muscle strength was measured with an isokinetic dynamometer from -60°.s-1 to 500°.s-1. The mechanical power generated during the first 4-s of a sprint run was measured on a treadmill ergometer developed to simulate sprint running. Run times over 10, 20, 30, and 40-m were measured on a track with 5 photoelectric cells, the ball velocity with a radar after a maximal soccer kick, the height of a vertical jump with an Ergojump. The maximal aerobic velocity, time performances on a 400-m run and blood lactate concentrations were measured on a track. Results: During the 3-week period, 6 players were injured during the normal soccer training while no injury was reported in the STP. For the remaining 2 groups (n=9), no muscle strength gain was measured after training. For STG, the peak power measured on the treadmill ergometer increased significantly by 15% from 17.47±1.44 w.kg1 to 20.05±2.65 w.kg-1, while the 10-m time decreased significantly by 4.5% from 1.845 ± 0.088 s to 1.761±0.100 s. For the other measurements, no difference was found between the 2 groups before and after the STP. Conclusion: The STP increased the maximal running speed over 10-m, and the peak power measured on the treadmill ergometer but not muscle strength. No injury was reported during the STP, while 6 injuries were reported during the normal soccer training. Thus, a 3-week STP is a good means to improve speed and lower limb muscle power with no risk of injury.
© Copyright 1999 5th IOC World Congress on Sport Sciences with the Annual Conference of Science and Medicine in Sport 1999. Alle Rechte vorbehalten.