If you rest longer between weightlifting sets (2.5 minutes instead of 1 minute), your arms grow bigger over 10 weeks — even if your strength doesn’t change.

If you do the same total amount of weightlifting work, it doesn’t matter much if you rest 20 seconds or 2 minutes between sets—your muscles grow and get stronger about the same either way.

If you lift light weights with short breaks between sets for eight weeks, your upper arms might grow bigger than if you lift heavy weights with long breaks—even if you do the same total amount of work. Light weights + quick rest = more muscle growth in this study.

Taking a bit more than a minute between sets when lifting weights might help your arms and legs grow slightly bigger, but the difference is so small it might not matter much in real life.

Taking a bit more than a minute between sets when lifting weights might help your arms and legs grow slightly more muscle, but the difference is so small it might not matter much in real life.

If young men lift light weights with very short breaks between sets for 8 weeks, their upper arms grow more than if they lift heavy weights with long breaks—even if they do the same total amount of lifting—because the short breaks create more muscle-burning stress that helps muscles grow bigger.