When men push with their legs using different exercises but at the same knee angle, their thigh muscles turn on in a similar way, even though one exercise uses more joints than the other.

When healthy guys push with their legs at a 90-degree bend, their quad muscles don’t fire in a straight line with how hard they push — the muscle activity changes unevenly as they push harder from 20% to 100% effort.

When healthy guys push with their legs, the electrical activity in one specific thigh muscle (vastus lateralis) goes up steadily with how hard they push — unlike two other thigh muscles — so it might be a better way to measure how much force their whole quad is producing.

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.

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.

When untrained men get stronger during dynamic leg movements like standing up, the biggest factor is how much their thigh muscles fire, especially when combined with changes in the deep thigh muscle’s fiber angle and overall muscle size.