You can make your workout feel harder and your muscles burn more by resting less between sets—but you can still lift the same total weight without getting weaker.

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.

If you lift the same total weight, your quads grow just as much whether you rest 20 seconds or 2 minutes between sets—so you don’t need to feel the burn to build muscle.

You breathe the hardest not when you’re lifting, but right after you finish a set and are resting—your body is catching up on oxygen debt built up during the effort.

When trained guys do lots of reps, they feel more tired, weaker longer, and more stressed than when they do fewer heavy reps — even though their muscles are damaged about the same.

Lifting lighter weights with very short breaks between sets makes your muscles swell up more right after working out than lifting heavy weights with long breaks—so if you want that pumped feeling fast, go light and quick.