Effects of Varied Versus Constant Loading Zones on Muscular Adaptations in Trained Men.

The purpose of this study was to compare the effects of a protocol employing a combination of loading zones vs. one employing a constant medium-repetition loading zone on muscular adaptations in resistance-trained men. 19 trained men (height=176.9±7.0 cm; body mass=83.1±11.8 kg; age=23.3±2.9 years) were randomly assigned to 1 of 2 experimental groups: a constant-rep resistance training (RT) routine (CONSTANT) that trained using 8-12 RM per set, or a varied-rep RT routine (VARIED) that trained with 2-4 RM per set on Day 1, 8-12 RM per set on Day 2, and 20-30 RM on Day 3 for 8 weeks. Results showed that both groups significantly increased markers of muscle strength, muscle thickness, and local muscular endurance, with no differences noted between groups. Effect sizes favored VARIED over CONSTANT condition for elbow flexor thickness (0.72 vs. 0.57), elbow extensor thickness (0.77 vs. 0.48), maximal bench press strength (0.80 vs. 0.57), and upper body muscle endurance (1.91 vs. 1.28). In conclusion, findings indicate that both varied and constant loading approaches can promote significant improvements in muscular adaptations in trained young men.

Effects of different volume-equated resistance training loading strategies on muscular adaptations in well-trained men.

Regimented resistance training has been shown to promote marked increases in skeletal muscle mass. Although muscle hypertrophy can be attained through a wide range of resistance training programs, the principle of specificity, which states that adaptations are specific to the nature of the applied stimulus, dictates that some programs will promote greater hypertrophy than others. Research is lacking, however, as to the best combination of variables required to maximize hypertophic gains. The purpose of this study was to investigate muscular adaptations to a volume-equated bodybuilding-type training program vs. a powerlifting-type routine in well-trained subjects. Seventeen young men were randomly assigned to either a hypertrophy-type resistance training group that performed 3 sets of 10 repetition maximum (RM) with 90 seconds rest or a strength-type resistance training (ST) group that performed 7 sets of 3RM with a 3-minute rest interval. After 8 weeks, no significant differences were noted in muscle thickness of the biceps brachii. Significant strength differences were found in favor of ST for the 1RM bench press, and a trend was found for greater increases in the 1RM squat. In conclusion, this study showed that both bodybuilding- and powerlifting-type training promote similar increases in muscular size, but powerlifting-type training is superior for enhancing maximal strength.