Mixed
In resistance-trained men, increasing training volume from 1 set to 5 sets per exercise per session significantly enhances muscle hypertrophy (specifically in elbow flexors, mid-thigh, and lateral thigh) without providing additional strength or endurance benefits.
If you are an experienced lifter, doing 1 set per exercise to failure is enough to build strength and endurance, saving you significant time. However, if your primary goal is maximizing muscle size, you should perform 3-5 sets per exercise. The extra sets will yield more muscle growth, but you won't get stronger faster by doing them. Prioritize volume for hypertrophy, but don't expect strength to improve just by adding sets.
Results showed significant preintervention to postintervention increases in strength and endurance in all groups, with no significant between-group differences. Alternatively, while all groups increased muscle size in most of the measured sites from preintervention to postintervention, significant increases favoring the higher-volume conditions were seen for the elbow flexors, mid-thigh, and lateral thigh.
Why this rating
Randomized controlled trial with trained subjects, though slightly underpowered due to dropouts.
Source
Resistance Training Volume Enhances Muscle Hypertrophy but Not Strength in Trained Men
Brad J. Schöenfeld et al. · Medicine & Science in Sports & Exercise · 2018
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