If you lift heavy weights or do lots of reps with lighter weights, your muscles grow at the same rate—so it doesn’t matter which way you train, as long as you’re already fit.

Lifting weights makes your muscles start building more protein right after the workout, and mixing up your routine a little bit gives your muscles a tiny extra boost right after lifting—but in the long run, both routines build about the same amount of muscle.

Your muscles make more protein at first when you start lifting weights, but after a few weeks, that boost fades—even if you keep lifting harder.

If you do lots of reps with lighter weights for six weeks, your body might make more of the non-muscle proteins inside your muscles than if you lift heavy weights with fewer reps — and this difference is pretty big.

Your muscles make more protein at first when you start lifting weights, but after a few weeks, that boost fades—even if you keep lifting harder.

Your muscles make more protein when you start lifting weights, but after a few weeks, that boost fades — even if you keep lifting harder — no matter if you use heavy or light weights.