A lot of coaches and athletes have the “more is better” mentality. If three sets are good, nine must be better. This is important in an athletic strength and conditioning setting because time is finite, so we want to get the most out of our limited training time.
Aube et al looked at the impact of volume (e.g. number of sets) on adaptations to strength training. They studied resistance trained 18-35 year old males who could squat at least double bodyweight. Subjects trained twice a week on three lower body exercises (squats, leg presses, glute ham raises). Subjects were divided into three experimental groups: 12 sets, 18 sets, 24 sets. The sets referred to the total number of weekly sets combined on squats and leg presses, sets were equally divided between squats and leg presses. Otherwise the training was the same; the first session was heavier at 6-8 reps/set, the second was lighter at 12-15 reps/set.
Results:
- 1-RM strength increased by about 5% for the 24 set group, 16% for the 18 set group, and 11% for the 12 set group.
- Reps to failure at 70% of 1-RM on the squat increased by 33% on the 24 set group, 15% on the 18 set group, and 35% on the 12 set group.
- Muscle thickness: anterior thigh muscle thickness (medial site) increased the most for the 12 set group and least for the 24 set group; at the distal site it increased the most for the 24 set group and the least for the 18 set group
So what’s going on here. First, strength, endurance, and hypertrophy all work a little differently and respond better to different stimuli. In terms of strength, 12 sets made great gains. 18 sets made better gains. There were diminishing returns for the 24 set group.
For endurance, more was better but not best. 12 sets had the best gains but they were real close to the 24 set group.
For hypertrophy, the 18 set group made the best gains, followed by 12 sets, followed by 24.
In other words, more is not necessarily better for strength, hypertrophy, and even endurance. There appears to be (as the authors called it) a U effect of volume (18 being most effective), 12 seems adequate but 24 seems like too much.
Aube, D., et al. (2022). Progressive resistance training volume: Effects on muscle thickness, mass, and strength adaptations in resistance-trained individuals. Journal of Strength and Conditioning Research, 36(3), 600-607.
