Most of the studies on this topic are not very well done—they often don’t report enough details, have small sample sizes, or use shaky methods, so we can’t trust their results fully.

Lifting weights until you can't do any more reps makes your muscles grow bigger than lifting weights without pushing to your limit, based on a big review of studies.

Even though muscles might grow a tiny bit more at the far end when stretched more, it’s so small that it doesn’t really matter in practice — all parts grow about the same.

If you're someone who works out casually, lifting weights with your muscles stretched might give you slightly bigger arms compared to mixing stretched and shortened positions — but the difference is small and we're not sure if it really matters in real life.

Working your muscles through a fuller range of motion during weight training might make them grow a little bigger than training with a shorter range, but it’s not always clear or the same for every muscle.

Lifting weights until you can't do any more reps doesn't make you stronger than stopping a few reps short, according to a big review of studies.