When you lift weights close to your limit, your muscles grow bigger better if you leave a few reps in the tank—but that same closeness doesn’t help you get stronger as much, which suggests your body builds muscle and strength in different ways.

If you lift weights until you can’t do another rep, your muscles will grow about the same no matter how heavy the weights are—but you’ll get stronger faster if you lift heavier weights.

You don’t need to push your muscles to absolute exhaustion to grow them—working them pretty hard (but not all the way to failure) might give you just as much muscle growth as going all out.

If you lift weights until you're almost too tired to do another rep, you'll likely build bigger muscles—but your strength gains won't be any better than if you stopped earlier, as long as you're doing the same total amount of work and lifting the same weight.

When you lift weights and push yourself almost to the point of not being able to do another rep, you’re more likely to build bigger muscles than if you stop earlier — even if you’re lifting the same weight or doing the same number of sets.

Muscle size and strength don’t respond the same way to more training—strength peaks faster, so adding more sets helps muscle growth longer than it helps strength.