When lifting lighter weights, pushing until you can't do any more reps helps build more muscle than stopping early. But with heavier weights, pushing to failure doesn't give much extra muscle growth compared to stopping a bit sooner.
Evidence from Studies
Supporting (2)
Community contributions welcome
Muscle Failure Promotes Greater Muscle Hypertrophy in Low-Load but Not in High-Load Resistance Training
This study looked at whether pushing muscles to failure during weight training helps build more muscle. It found that for light weights, going to failure does help grow muscle more, but for heavy weights, it doesn't make much difference, which matches the claim exactly.
Muscle Failure Promotes Greater Muscle Hypertrophy in Low-Load but Not in High-Load Resistance Training
This study looked at whether pushing muscles to failure helps them grow more with light weights but not with heavy weights, and it found exactly that, so it supports the claim.
Contradicting (3)
Community contributions welcome
Low-Load Resistance Training to Volitional Failure Induces Muscle Hypertrophy Similar to Volume-Matched, Velocity Fatigue
The study only looked at low-load training and didn't compare failure vs. non-failure for high-load training like the claim does, so it can't confirm or deny the claim.
Muscle Hypertrophy, Strength, and Salivary Hormone Changes Following 9 Weeks of High- or Low-Load Resistance Training
The study didn't compare training to failure with not training to failure, so it can't tell us if failure helps muscle growth more in low-load training.
Divergent Strength Gains but Similar Hypertrophy After Low-Load and High-Load Resistance Exercise Training in Trained Individuals: Many Roads Lead to Rome.
The study found that both low-load and high-load training to failure made muscles grow about the same amount, but the claim says low-load training to failure helps growth more than high-load, so the study contradicts the claim.
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.