Lifting weights until you're tired, whether with light or heavy weights, makes your muscles bigger and stronger in the same way for beginners.

Lifting weights until you can't do any more reps makes your muscles grow just as much, no matter how heavy or light the weights are.

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.

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

Working out with weights three times a week for 10 weeks makes you better at doing more reps — but how much better depends on whether you used heavy or light weights.

When healthy young men lift weights until they're too tired to continue, their muscles grow about the same amount in both their arms and legs, no matter how heavy the weights are.