When guys who’ve never lifted weights before start training their legs for 15 weeks, the more their thigh muscles grow, the stronger they get—so muscle growth is probably why they’re getting stronger, not just better at lifting.

When guys who’ve never lifted weights before train their legs for 15 weeks, the more their muscles grow, the stronger they get—so muscle growth is mostly why they get stronger.

If you're new to lifting and using light weights, you need to push your muscles until they can't do another rep to grow them bigger—otherwise, even doing more reps won't help.

If you're lifting heavy weights, you don't need to push to absolute exhaustion to grow your muscles—stopping just before failure works just as well, as long as you're lifting heavy enough.

When untrained men get stronger in a static leg press, the main reason is that their thigh muscle near the hip gets bigger and its fibers angle more, which helps push harder.

Whether you take short or long breaks between leg exercises, as long as you do the same total number of reps, your inner and outer thigh muscles grow about the same.