For beginners lifting weights, pushing muscles to complete exhaustion doesn't build more muscle than stopping just short of exhaustion, as long as the total amount of lifting is the same over 8 weeks.

When people lift light weights until they can't anymore, their thigh muscles grow much more than if they just lift lightly without pushing to the limit, showing that working really hard is key for muscle growth even with light weights.

For beginners lifting weights, pushing until you can't do any more reps doesn't give extra strength gains compared to stopping earlier, as long as you do the same total amount of work. Both ways lead to similar improvements in how much you can lift.

When lifting lighter weights, you need to push until you can't do any more reps to build as much muscle as lifting heavy weights. But with heavy weights, you can build a lot of muscle without pushing to total exhaustion.

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.

Lifting heavy weights three times a week for six weeks makes untrained young men much stronger than lifting light weights, even though both groups gain about the same amount of muscle size.