The fountain of youth just might be filled with sweat: Certain types of exercise can help you age better, recent research published in the European Heart Journal suggests.

In the study, researchers enrolled 266 young, healthy participants who were generally inactive. Then, they split them into four groups: an endurance training group, a HIIT group, a circuit-based weight lifting group, and a sedentary control group.

The three exercise groups performed 45-minute sessions three times per week (the control group continued doing what they were doing, which, well, wasn’t much). At the end of six months, researchers looked at the lengths of their telomeres—the caps at the ends of our chromosomes, which serve in protecting our DNA from deterioration—as well as activity of telomerase, an enzyme that helps replenish lost telomeres.

The researchers discovered that both telomerase length and activity increased by two- to three-fold in the endurance and HIIT training groups compared to the sedentary group.

That’s important, since as we age, our telomeres naturally shorten and deteriorate, leaving our cells vulnerable to damage, study coauthor, Christian Werner, Ph.D., of Saarland University in Saarbrücken, Germany, told Runner’s World. So the more we can slow down this process, the more beneficial it will be.

“Shortened and damaged telomeres signal to the cell to halt growth and multiplication and to become senescent,” he said. “This is an important hallmark of aging in the cells.”

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So, if you have longer telomeres, does it correlate to a younger biological age? That’s a tricky question, Werner said, and one that doesn’t yet have a clear answer. But research has indicated that stronger telomeres help you age better, he said—for example, with stronger cardiac and muscular function. The more your telomeres stay intact, the more resistant the cells are to stress and inflammation, he said, two of the biggest components in age-related conditions.

Surprisingly, the researchers didn’t find any telomere-related benefits to resistance training. One possible explanation is a change in level of nitric oxide synthase, an enzyme that produces a messenger molecule that increases the response of telomerase, he said. The enzyme was triggered only by endurance training, he said, but remained unchanged in resistance training.

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Elizabeth Millard

Elizabeth Millard is a freelance writer focusing on health, wellness, fitness, and food.