This study only looked at how many sets and how often you lift — it didn’t check how hard you lift or what exercises you do, so those factors could still matter a lot.

Muscle size and strength don’t respond the same way to more training—strength peaks faster, so adding more sets helps muscle growth longer than it helps strength.

Training more often helps you get stronger, but doesn’t seem to help you get bigger muscles—so frequency matters more for strength than for size.

Muscle size and strength don’t grow the same way when you lift more — strength hits a ceiling faster than muscle size, meaning they’re probably controlled by different biological processes.

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.

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.