I’ve flirted with distance running, but in the end always felt like it was wearing me down rather than paving the way toward a strong, lithe old age, which is how yoga makes me feel.

At last, an honest-to-goodness expert to back me up: Here, former sub-2:20 marathoner Mark Sisson talks about how endurance training may speed the body’s aging process.

If you enjoy endurance exercise, it’s probably worth the extra oxidation. Who knows how subtle the aging effect is, if it even exists, and there are obviously a ton of countervailing health benefits compared to a sedentary lifestyle.

But if you’re like me and would rather play hot potato with a uranium bomb than run more than 5 miles at a stretch, this is proof positive that you need never do it again.