A popular approach to weight training is to keep lifting until you can’t manage another repetition.

This is known as pushing yourself to failure. And it goes hand in hand with the common refrain –no pain, no gain.

But does this really develop better results? Do you need your arms or legs to fold in order to become stronger? Or get those bigger muscles?

Or is there some wiggle room that allows you to back off from all-out collapse, and limit your risk of injury?

This is an important consideration for all of us.

But especially for people over the age of 50 … or even 40, if we stop kidding ourselves.

For the sake of our bones and balance, people from middle age onwards are encouraged to regularly engage in weight or resistance training.

We may not want to be body builders, but we want results, at least in terms of getting stronger. We want to know how far we need to push ourselves.

Interestingly, given the endless blogging and fitness advice out there, the question has not been satisfactorily answered.

A new study

Researchers from Florida Atlantic University say that it’s “still unclear how close to failure one needs to go to maximise muscle growth and strength”.

To get some answers they collected data from 55 studies “and ran detailed statistical analyses to see how different reps in reserve levels affected strength and muscle growth”.

They focused on how training close to failure affects muscle growth in the main muscles used in an exercise.

For example, they said, if an individual was doing leg presses, the focus was on how training close to failure affects the quadriceps.

The results

The researchers found that “how close you train to failure doesn’t have a clear impact on strength gains”.

In other words, whether you stop with plenty of reps left in the tank, or close to failure, “your strength improvement appears to be similar”.

This is encouraging news in terms of injury prevention.

On the other hand, muscle size (hypertrophy) does seem to benefit from training closer to failure.

The closer you are to failure when you stop your sets, the more muscle growth you tend to see. But this doesn’t mean you have to go all the way to collapse.

By leaving four or five reps in the tank, means you’re in better shape for training again sooner.

What the researcher says

Dr Michael C Zourdos is senior author and professor and chair of the Department of Exercise Science and Health Promotion within FAU’s Charles E. Schmidt College of Science.

He said: “If you’re aiming for muscle growth, training closer to failure might be more effective.

“In other words, it doesn’t matter if you adjust training volume by changing sets or reps. The relationship between how close you train to failure and muscle growth remains the same.”

For strength, he said, how close you push to failure doesn’t seem to matter as much.

Practical advice

The researchers recommend people who aim to build muscle should work within a desired range of 0 to 5 reps short of failure.

This will optimise muscle growth and minimise injury risk.

For strength training, they suggest individuals should work toward heavier loads instead of pushing their muscles to failure.

As such, they recommend that to train to gain strength, individuals should stop about 3 to 5 reps short of failure without applying additional physical strain on the body.

The findings help underscore “the difficulties of training close to failure, which can be tough and harder to recover from, potentially impacting long-term performance negatively”.