The effect of unilateral and bilateral leg press on strength, power, and athletic performance in Scottish adolescent rugby players (Oral Presentation)

PURPOSE: In recent years, the use of unilateral resistance training has become popular in strength and conditioning practice. The potential benefit of unilateral resistance training may include 1. A higher relative intensity and better injury prevention 2. Unilateral training may be as effective as bilateral training. A previous study found that bilateral and unilateral resistance training may be equally efficacious in improving measures of lower body strength and power however this has not yet been investigated in adolescent population. Because of young people’s immature physiological and psychological state, the response to the training may be different from adults. Therefore, the purpose of this study was to compare the effects of 5 weeks of bilateral and unilateral leg press training on lower body strength, jumping and sprinting performance in adolescent rugby players.

METHODS: Twenty-six adolescent rugby players were assigned to a 5 weeks unilateral (n= 9) or bilateral (n = 9) training programme supplementary to habitual training, or a control group (n = 8) using a stratified blocked randomization approach, with biological maturation the blocking variable. Five-RM unilateral/bilateral leg press strength, 30-m sprint and countermovement jump were tested before and after the 5-weeks intervention. Statistical evaluation was accomplished with a 3×2 (group × time) repeated measure analysis of variance. Change score Δ (POST-PRE) within each group was compared by one-way analysis of variance.

RESULTS: No significant PRE to POST difference was seen in any of 30-m sprint, countermovement jump, 5-RM leg press and 5-RM single leg press variables. Significant difference was seen in 5-RM single leg press test, the unilateral group showed greater improvement than the bilateral group and control group. No significant differences were seen between the groups in 30-m sprint,
countermovement jump, 5-RM leg press.

CONCLUSIONS: This study was the first to compare the effects of unilateral and bilateral resistance training on strength and power
in adolescent male rugby union players. The findings indicate that 5-weeks twice weekly unilateral/bilateral leg press training has limited effect on improving lower body strength and may not sufficient to impro