You can build muscle just as well by lifting light weights with your blood partially squeezed off, as you can by lifting heavy weights—so maybe it’s not the weight itself that matters most, but how much your muscles burn and swell up.

Doing heavy weightlifting with your legs squeezed to restrict blood flow doesn't make your muscles grow more than just doing heavy weightlifting normally — at least not for most people who haven't trained before.

Doing light weight training with restricted blood flow can still make your arm muscles grow bigger — and it doesn’t cause swelling or damage, according to a 3-week study on people’s biceps.

If you lift heavy weights with a special band that cuts off some blood flow, it doesn’t make your muscles stronger or bigger than just lifting heavy weights alone—even though your muscles feel more burned.

Doing light workouts with restricted blood flow might be just as good as heavy lifting for building strength — but easier on your joints and muscles, especially if you're recovering or not very strong.

When you wrap your arm tightly and lift light weights, your muscles still grow — and your body turns on the same growth signals as when you lift heavy weights, which hints that the burning feeling might be key.