Beta-alanine buffers muscle acidity, extending time-to-fatigue — but only for continuous efforts lasting roughly 1 to 4 minutes. A 2012 meta-analysis found no effect for exercise under 60 seconds, meaning it doesn't help typical 6-15 rep hypertrophy sets used in standard Resistance Training Programming Principles.
Useful for endurance training, high-rep circuit-style work, or any continuous effort in the 1-4 minute window. Not useful for standard hypertrophy training, where individual sets are too short (well under a minute of continuous tension) for acidity buffering to matter. Contrast with Creatine Supplementation and Caffeine as an Ergogenic Supplement, which have broader effective ranges for lifters regardless of rep scheme.
Source: Jeff Nippard, "The Worst Supplements Everyone Takes For Muscle Growth" (2026).