Health Claims

When male bodybuilders do leg extensions with their hips more bent, the top and middle parts of their front thigh muscle don’t work as hard — they show less activity and fatigue compared to when the...

When male bodybuilders do leg extensions with their hips bent at 40 degrees, the front thigh muscle works harder in certain areas than when their hips are bent more at 80 degrees.

When you lean back a bit, your legs can push harder at the knee even though your muscles aren't working any harder—this might be because of how your body is positioned, not because your brain is...

When people sit at different angles—leaning forward or backward—their brain sends the same signal to their thigh muscles to squeeze as hard as possible, even though the strength they can produce...

If you're sitting reclined back a bit (like leaning back in your office chair), your leg muscles can push a little harder than if you're leaning forward—by about 5 to 11%—at least in healthy adults.

Older guys getting back into exercise after leg inactivity don’t seem to gain or lose muscle strength or size from taking ibuprofen every day, even if they’re also drinking protein shakes.

After older guys rest their legs for a bit, getting back to strength training with extra protein might help their leg muscles grow back stronger than before they took the break.

If older guys between 60 and 80 don’t use their legs for two weeks, they lose leg muscle and strength—but just two weeks of exercise plus drinking protein twice a day can bring it all back.

Taking a high dose of ibuprofen every day might slow down your strength gains when doing certain types of intense exercise, especially flywheel training, more than regular weightlifting — and the...

Taking a low-dose aspirin every day doesn’t seem to slow down muscle growth or strength gains when young adults do weight training for 8 weeks — and they still gained about 7.5% more quad muscle...

Taking a lot of ibuprofen while working out might slow down your muscle growth — people on high-dose ibuprofen gained less muscle over 8 weeks compared to those on a low-dose aspirin-like drug.

For guys who lift weights, the inner thigh muscle works just as hard during leg presses and knee extensions — these two exercises use that muscle in a similar way.

For guys who lift weights, doing leg presses or kickbacks works the butt muscle just about the same — neither one gives you a bigger advantage in muscle activation.

If you're a guy who lifts weights, doing kickbacks might work your back thigh muscle way more than the leg press — like 76% more, according to one study.

If you're a guy who lifts weights, your front thigh muscle works way harder during leg extensions than during leg presses — probably because the movement challenges how that muscle crosses two joints...

For guys who lift weights, the leg press works the main quad muscle harder than the knee extension machine, based on electrical activity in the muscle.

For women doing squats in BODYPUMP classes, how deep they squat and how heavy the weight don’t affect each other when it comes to which muscles are working — each factor works on its own.

For women doing Les Mills BODYPUMP, using heavier weights (about 38% of your body weight) in squats makes certain leg muscles work harder than using lighter weights (23% of your body weight).

Women doing Les Mills workouts get more muscle activation in their quads, glutes, hamstrings, and calves when they squat deeper (90 degrees) compared to a more shallow squat (125 degrees).

When women who lift weights do squats with different levels of heavy weights, the way their thigh and butt muscles work together stays the same — no matter how heavy the weight is.

When women who lift weights do squats with a light weight (about 40% of their max), their butt and hamstring muscles work together in perfect balance as they lower down.

When women who lift weights do squats with 80% of their max weight, their butt muscles work way harder compared to their hamstrings — more than with lighter or heavier weights.

For women who lift weights regularly, squatting with 80% or 90% of your max weight activates your muscles about the same — going heavier doesn’t seem to turn on more muscle once you hit that range.

When women who lift weights do squats with a really heavy weight (close to their max), their leg and butt muscles have to work a lot harder than when they use lighter weights.