Influence of Resistance Training Proximity-to-Failure on Skeletal Muscle Hypertrophy: A Systematic Review with Meta-analysis

When people who’ve never lifted weights before start training, some gain just a little muscle—like half a kilo—while others gain a lot, up to three kilos, in about two to three months.

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.

Doing more sets of weightlifting seems to build muscle more reliably than how close you get to failing on each set—whether you stop short or push to exhaustion doesn’t change the muscle growth much if you’re doing the same number of sets.

Lifting weights until you can't do another rep doesn't help you build more muscle than stopping before you hit total exhaustion—so you don't need to push yourself to the absolute limit to get the best results.

Pushing yourself harder during weightlifting by stopping later (more than 25% slower than your fastest rep) doesn’t help you build more muscle than stopping a bit earlier (20–25% slower)—the difference is so tiny it doesn’t really matter.

Lifting lighter weights really close to failure might build muscle just as well as lifting heavy weights, but the evidence isn’t strong enough to say for sure — it might depend on how you combine weight and effort.