The Summary
Researchers investigated how varying fatigue levels affect squat performance and muscle growth. Fifty-one trained men completed an eight-week squat program using moderate loads, assigned to stop sets when bar speed dropped by 0%, 10%, 20%, or 40%. While all groups increased quadriceps size—with the 40% velocity-loss group showing the greatest growth trends—the 20% velocity-loss group achieved the largest gains in maximal strength and movement speed under heavy loads. Pushing to high fatigue yielded comparatively lower strength gains.
Why this is interesting
Many lifters assume training close to failure is necessary for both size and strength. This study reveals a clear divergence: pushing deep into fatigue promotes muscle growth, but terminating sets while movements remain crisp and fast optimizes pure strength gains. For gym-goers, this means your approach should match your target. If your primary aim is building raw power and lifting heavier weights, leaving several reps in reserve produces superior neuromuscular adaptations. If maximizing muscle volume is the objective, tolerating higher fatigue within sets remains an effective route.