RCTVelocity loss
A controlled trial found that stopping sets at a lower velocity-loss threshold (around 20% bar-speed loss) produced strength gains similar to a higher threshold (around 40%) while performing far fewer repetitions and generating less fatigue; the higher velocity-loss condition produced somewhat more hypertrophy but more fatigue. Bar-speed drop is a usable proxy for effort and fatigue.
Rule: For strength and efficiency, cap velocity loss within a set at roughly 20-25%; allow larger velocity loss only when extra hypertrophy justifies the added fatigue.
- Pareja-Blanco F, Rodriguez-Rosell D, Sanchez-Medina L, et al. (2017). Effects of velocity loss during resistance training on athletic performance, strength gains and muscle adaptations doi:10.1111/sms.12678