Do you have to train to failure to grow?

Grinding every set until the bar stops moving feels like the most serious way to train. It is also exhausting, and it makes it harder to keep good form and come back fresh next session. So is it necessary?

What the research found

A 2024 series of meta-regressions by Robinson and colleagues pooled the training studies and estimated how close to failure the sets ended, compared with how much muscle and strength people gained. For muscle growth, sets that ended closer to failure tended to build more. For strength, there was no clear relationship: stopping a few reps short worked about as well.

A 2023 meta-analysis by Refalo and colleagues, focused on muscle growth, found that training all the way to failure was not shown to build more muscle than stopping a little short of it. The authors also note these estimates are exploratory, so treat them as a guide rather than an exact rule.

What to do with this

• For size, finish your sets close to failure: the last rep should be genuinely hard.
• For strength, leaving a rep or two in the tank is fine, and it keeps your technique cleaner.
• True failure is most practical on safer exercises, like machines or curls, rather than a heavy squat without a spotter.
• Track your reps and weights so you know when a set was really close, instead of guessing.

You do not need to max out every set. Just finish close.

Some authors suggest stopping somewhere between zero and a few reps short of failure. That is their practical suggestion rather than a hard finding, so treat it as a starting point and adjust to how you recover.