Lifting weights after 60 may strengthen something most people never think about training: the muscles that help them breathe.

A randomized clinical trial involving 60 adults ages 60 to 75 found that 12 weeks of resistance training improved respiratory muscle strength while changing several biological markers associated with healthy aging. The findings, published in the Journal of Functional Morphology and Kinesiology , suggest weightlifting’s benefits extend beyond visible muscle.

Related: Scientists Found a Surprising Longevity Benefit From Lifting Weights

The Biggest Change Wasn’t Muscle Size

Researchers randomly assigned participants to either a supervised resistance-training program or a control group.…