If you lift weights until you can’t do another rep—whether you use heavy weights or light ones—you’ll end up with about the same muscle growth after nine weeks, as long as you’re putting in the same effort and number of reps.

When young male athletes lift weights until they can't anymore, it doesn't matter much whether they use heavy weights or lighter ones—both ways build about the same amount of muscle after 8 weeks.

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.

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.

You can build muscle just as well lifting light weights as heavy ones — as long as you push yourself until you can’t do another rep.

Lifting heavy weights and lifting lighter weights both build muscle about the same amount in healthy adults, as long as you do enough reps until you can't lift anymore.