Your muscles naturally atrophy with age, meaning that you have to work harder than you once did to get in shape. Bones gradually get weaker with time, which increases the risk of a break.
Middle-aged and older men are just more likely to have accumulated more injuries along the way, especially in the knees, back and ankles. “You’ve got a lot of sins to atone for when you hit middle age,” says James Garrick, M.D., director of the Center for Sports Medicine in San Francisco. A lot of those prior injuries are likely to never have been properly rehabilitated. So you’ve got the combined risk of developing a new injury and re-injuring an old one.
As a result, middle-aged and older men need to take it a little easier on their bodies than they did in high school. But that’s not what always happens. “The biggest problem for older guys who exercise is that they don’t realize that their bodies have changed,” Garrick says. The upshot: You can’t take up a new sport as abruptly as you did when you were younger.
Your body can’t adapt as well to a sudden increase in exercise and doesn’t bounce back as easily afterwards. “If you’re planning on starting a new activity, gradually increase your exercise a month beforehand,” says Kenneth Brummel-Smith, M.D., president of the American Geriatric Society.
(Source: Harvard’s InteliHealth website)