Strong evidence

More hard sets per muscle per week produce more growth, across the range most people train in.

In practice

If growth has stalled and you're recovering fine, adding a set or two per muscle per week is the first lever to pull — before changing exercises or chasing a new programme.

What it doesn't say

The relationship is graded, not unlimited: gains per extra set shrink as volume climbs, and more sets cost more time and more fatigue. Most of the underlying studies are short and run on younger men.

Sources

• Schoenfeld BJ, Ogborn D, Krieger JW (2017). Dose-response relationship between weekly resistance training volume and increases in muscle mass: a systematic review and meta-analysis. Journal of Sports Sciences, 35(11):1073–1082. doi.org/10.1080/02640414.2016.1210197
• Pelland JC, Remmert JF, Robinson ZP, Hinson SR, Zourdos MC (2026). The resistance training dose response: meta-regressions exploring the effects of weekly volume and frequency on muscle hypertrophy and strength gains. Sports Medicine. doi.org/10.1007/s40279-025-02344-w