People who train both legs together show bigger increases in muscle electrical activity during double-leg lifts than those who train one leg at a time, suggesting their nervous systems become more active during those movements.

When guys who’ve never lifted weights before start training, the more their thigh muscles ‘fire up’ during max efforts, the stronger they tend to get—both in holding a heavy position and in lifting one heavy weight.

When untrained men get stronger during dynamic leg extensions, the biggest factor is how much they can turn on their thigh muscles — bigger muscles and fiber angles help a little, but turning on the muscles harder matters most.

You might not feel stronger right after this training, but your strength keeps going up for weeks after you stop — the best gains happen when you’re resting.

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.

When comparing hip thrusts and squats at the same effort level, the front thigh muscle (quadriceps) works just as hard in both exercises.