Resistance training performed to volitional muscular failure produces equivalent hypertrophic outcomes across a wide range of loads and repetition ranges.

Study: Divergent Strength Gains but Similar Hypertrophy After Low-Load and High-Load Resistance Exercise Training in Trained Individuals: Many Roads Lead to Rome.

When people lift weights until they can't do another rep, whether they use light or heavy weights, their muscles grow about the same amount — the study proved this by comparing both methods in trained people.

Study: Delayed myonuclear addition, myofiber hypertrophy, and increases in strength with high-frequency low-load blood flow restricted training to volitional failure.

This study found that lifting very light weights until you can't do another rep — while also squeezing your leg to restrict blood flow — still made muscles grow big. This supports the idea that going all-out matters more than how heavy the weights are.

Study: Resistance training load does not determine resistance training-induced hypertrophy across upper and lower limbs in healthy young males.

When people lift weights until they can’t do another rep, whether they use heavy or light weights, their muscles grow about the same — the key is pushing until exhaustion, not how heavy the weight is.