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.

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.

Doing light weight exercises until you can't do any more for 8 weeks won't make your arms stronger or more powerful if you're new to lifting — you probably need to lift heavier or move faster to see real gains.

If you lift weights until you can’t do another rep or stop before that—as long as you do the same total amount of work—you’ll get just as strong either way. You don’t have to push to absolute exhaustion to build strength.

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 or stop a little earlier—but do the same total amount of work—your muscles will grow and get just as strong either way. So you don’t have to push to absolute failure to see results.