Health Claims

If regular gym-goers train their biceps by lifting in a way that stretches the muscle more, they’ll likely gain more muscle size over two months.

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.

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 weightlifting with blood flow restriction four times a week for three weeks can make arm muscles grow a little in young, trained guys — about 4% to 8% bigger.

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.

If you're a guy new to lifting, doing bicep curls with your arms in front of you or behind you doesn’t really make a difference in how much your biceps grow — both ways work about the same.

If you're a guy new to lifting, doing bicep curls with your arms in front of you or behind you gives your brachialis muscle (a hidden arm muscle) about the same growth — around 8–10% after 10 weeks. It doesn’t matter much where your shoulders are, as long as the resistance feels the same.

If you're a guy new to lifting and do bicep curls with a cable machine for 10 weeks, your biceps grow evenly from top to bottom — not more in one spot — no matter how your shoulder is positioned.

If you're a young guy just starting out, doing bicep curls with your arms in front of you or behind you gives about the same strength gains after 10 weeks — even if one seems to improve a bit more, the difference isn’t really meaningful.

For guys new to lifting, doing bicep curls with your arms in front of your body works just as well for building arm muscle as doing them with your arms behind you — both give about the same 6% to 9% growth in 10 weeks.

If young women do incline bicep curls twice a week for 8 weeks, they’ll get stronger at that exact move compared to doing preacher curls — it’s like getting better at one exercise by practicing that one specifically.

If young women do preacher curls twice a week for 8 weeks, they’ll get stronger at preacher curls than if they did incline curls instead — and that makes sense because your body gets best at the moves you actually practice.

If young women do preacher curls instead of incline curls during their arm workouts for 8 weeks, they’ll likely gain more muscle in the lower part of their biceps.

If young women do incline bicep curls twice a week for 8 weeks, their upper arm muscles grow more than if they did preacher curls — showing that the type of curl might change where the muscle grows most.

Young guys who took a break from working out didn’t see much muscle growth in certain areas—like the middle of the outer thigh and upper arm—after nine weeks of doing the same strength exercises.

If young guys who haven't worked out in a while do different leg exercises for 9 weeks, their upper outer thigh muscles grow more than the middle part — even with exercise variety, growth isn't even.

If young guys who haven’t worked out in a while switch up their strength exercises for the same muscles, they’ll likely build muscle more evenly across their thighs and arms over nine weeks compared to doing the same moves every time.

Measuring arm muscle thickness with ultrasound gives very consistent results when done the same way, so it’s good for tracking muscle growth over time.

For women who work out regularly, both preacher curls and inclined curls build arm muscle just about the same way — no matter where you look along the upper arm.

Doing a specific type of bicep curl on an incline with changing resistance doesn't seem to make certain parts of the upper arm muscles grow more in women who work out regularly — even after doing it consistently for 9 weeks.

For women who work out regularly, doing preacher curls that stretch the biceps a lot might help build more muscle in the lower part of the upper arm—about an 8.8% increase—compared to other curl types.

Your body uses a special chemical pathway to turn tryptophan from food into energy molecules, and this process might be linked to how we age and manage energy in our cells.

Turning off certain genes in mice changes their body chemistry in ways that depend on the tissue and whether they're male or female — and these changes are linked to how they age.