Some people think mixing up your leg workouts (like changing weights or angles) might make all parts of your quadriceps grow better than doing the same routine over and over—but right now, science hasn’t proven this for sure.

Doing strength exercises with your muscles stretched more or less doesn’t seem to make much difference in how much each part of the muscle grows — all parts grow about the same.

Even the middle parts of your muscles grow more when you stretch them fully during workouts — it’s not just the ends that benefit from full range of motion.

Doing varied weight workouts might hurt your muscles a little less than doing the same routine over and over—but you still gain just as much muscle, meaning you don’t need to feel wrecked to get stronger.

Most of the research on how much to lift and how often was done on young men who already train—so we don’t know if the same rules apply to women, older people, or beginners.

Doing your workouts more often per week doesn’t seem to help you build more muscle, as long as the total amount of lifting stays the same.