Even lifting light weights, as long as you push until you can't do another rep, can build muscle just as well as lifting heavy weights in people who already train regularly.

Whether you lift light weights with lots of reps or heavy weights with few reps—so long as you push until you can’t do another rep—you’ll build muscle about the same amount.

If you lift weights until you can’t do another rep, it doesn’t matter if you’re using light, medium, or heavy weights—you’ll still grow your muscles about the same, as long as you push yourself hard and do enough total work.

If young men lift weights with the same total effort—whether they use heavy weights with long breaks or light weights with short breaks—they’ll still grow about the same amount of muscle. So, different ways of lifting can both work.

Whether you lift heavy weights with fewer reps or light weights with more reps—as long as you push until you can’t do another rep—your muscles grow about the same amount.

Getting stronger from lifting weights doesn’t always mean your muscles are getting bigger—and vice versa. Strength and size don’t go hand in hand.