If you're new to lifting weights and do bicep curls with heavy weights, then wrap your arm tightly after exercising, you might end up with slightly less muscle growth in your upper arm compared to not wrapping it at all.

When people do light weight training with blood flow restriction on their biceps, the muscle grows evenly no matter if they do the exercise with their arm bent a lot or a little — growth looks the same along the whole muscle.

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.

For young guys who lift weights, squeezing the biceps at the top or bottom of the move doesn’t make a difference in muscle growth when using light weights with blood flow restriction.

After doing heavy weight training, if women who’ve never trained before use a tight band around their arm afterward, their arm muscles don’t get any thicker—but men’s muscles still grow normally.

For guys who lift weights, doing arm curls with the arm stretched out doesn’t build more muscle than doing them with the arm bent, even when using light weights and blood flow restriction — at least over 3 weeks.