As runners, we spend a lot of time thinking about muscles, shoes, and pace. But if there’s one part of your body that quietly takes a beating with every step, it’s your tendons—and they deserve more attention, especially as we get older. Tendons are the tough connective tissues that link muscle to bone. They store and release energy with every stride, acting like springs. But with age, they become less forgiving. They stiffen, heal more slowly, and lose some of their bounce.