Purpose: The purpose of this study was to determine the effects of increasing training volume from one set to three sets on muscular strength, muscular endurance, and body composition in adult recreational weight lifters.
Methods: Forty-two adults (age 39.7 +/- 6.2 yr; 6.2 +/- 4.6 yr weight training experience) who had been performing one set using a nine-exercise resistance training circuit (RTC) for a minimum of 1 yr participated in this study. Subjects continued to perform one set (EX-1; N = 21) or performed three sets (EX-3; N = 21) of 8-12 repetitions to muscular failure 3 d x wk(-1) for 13 wk using RTC. One repetition maximums (1-RM) were measured for leg extension (LE), leg curl (LC), chest press (CP), overhead press (OP), and biceps curl (BC). Muscular endurance was evaluated for the CP and LE as the number of repetitions to failure using 75% of pretraining 1-RM. Body composition was estimated using the sum of seven skinfold measures.
Results: Both groups significantly improved muscular endurance and 1 RM strength (EX-1 by: 13.6% LE; 9.2% LC; 11.9% CP; 8.7% OP; 8.3% BC; and EX-3 by: 12.8% LE; 12.0% LC; 13.5% CP; 12.4% OP; 10.3% BC) (P < 0.05). Both groups significantly improved lean body mass (P < 0.05). No significant differences between groups were found for any of the test variables (P > 0.05).
Conclusion: Both groups significantly improved muscular fitness and body composition as a result of the 13 wk of training. The results show that one-set programs are still effective even after a year of training and that increasing training volume over 13 wk does not lead to significantly greater improvements in fitness for adult recreational weight lifters.