If you do light weightlifting with a band around your arm to restrict blood flow, whether you're pushing or lowering the weight doesn’t seem to matter—both ways make your muscles stronger and bigger about the same amount in four weeks.

If young women do light weightlifting while wearing special bands that squeeze their arms or legs, they can get stronger and their muscles can grow bigger in just four weeks—without lifting heavy weights at all.

If young women do light weightlifting with a special band that restricts blood flow for four weeks, their muscles get stronger and bigger—even after just two weeks—without having to lift heavy weights.

When young women do light weightlifting with bands that squeeze their arms or legs, their muscles don’t get better at receiving signals from their brain—but they still get stronger. This means something else, like muscle swelling or chemical changes, must be making them stronger.

If you're a young guy new to weightlifting and you use a blood pressure cuff to restrict blood flow while lifting, it doesn't matter whether you squeeze the cuff while you're pushing the weight up or while you're resting between sets—either way, you'll gain the same amount of strength and muscle.

If you're new to lifting weights, adding blood flow restriction after your workout won't make your muscles grow any more than just lifting weights by itself—even if you do the same amount of work.