Comparison of two lower-body modes of endurance training on lower-body strength development while concurrently training.

The most recent American College of Sports Medicine (1998) recommendations for quantity and quality of exercise includes both resistance and endurance exercise components. Skeletal muscle adaptations to resistance-only and endurance-only programs may be different and possibly antagonistic when both types of training are imposed concurrently. The present study examined the effect of two different modes of lower-body endurance exercise (i.e., cycle ergometry and incline treadmill walking) on lower-body strength development with concurrent resistance training designed to improve lower-body strength (i.e., bilateral leg press 1 repetition maximum [RM]). Thirty untrained participants (22 men and 8 women, ages 18-23) were randomly assigned to one of 3 training groups (resistance only [R], N = 10; resistance + cycle ergometry [RC], N = 10; and resistance + incline treadmill [RT], N = 10). The 3 training groups exercised twice per week for 9 weeks. The reduced frequency of exercise treatments were selected specifically to avoid overtraining for in-season athletes attempting to maintain offseason conditioning. Body mass and body composition measurements were taken pre- and post-training. Before training began, 3 weeks of training, 6 weeks of training, and after training, the participants also performed a 1RM test for lower-body strength. Analysis of variance comparisons with repeated measures revealed the following statistically significant changes (alpha = 0.05) in the 3 training groups over time: (a) when men and women were combined, body mass of R was significantly greater than RC and RT post-training; (b) body mass of men only was significantly greater than RC and RT post-training; (c) body composition of men only was significantly smaller for RC and RT compared with R; (d) when men and women were combined, percent change in strength revealed significantly greater gains in R compared with RT at 6 weeks; (e) when men and women were combined, percent change in strength revealed significantly greater gains in R compared with RC and RT post-training; (f) percent change in strength for men only was significantly greater for R compared with RT at 3 weeks; (g) percent change in strength for men only was significantly greater for R compared with RC and RT at 6 weeks, and RC was significantly greater than RT at 6 weeks; (h) percent change in strength in men only was significantly greater for R compared with RC and RT post-training, and RC was significantly greater than RT post-training; and (i) percent change in strength in women was significantly greater in R compared with RT post-training. The findings confirm previous studies that reported attenuated strength development with concurrent resistance and endurance training compared with resistance-only training. More importantly, this study indicates that the mode of endurance exercise in concurrent training regimens may play a role in the development of strength. Specifically, it seems that cycling is superior to treadmill endurance training for an individual with the goal of developing strength in a multijoint movement (i.e., leg press or squat) in the lower-body because it more closely mimics the biomechanical movement of these exercises.

RCT Entities:   Population Interventions Outcomes