If you happened to read my post the other day “23 1/2” and saw how exercise can prevent muscle loss as you age, Alex Hutchinson over at Sweat Science just posted a follow up: the benefit of exercise to prevent muscle loss only works for the muscles you actually use. So, an aging runner (or cyclist — sorry, honey) can maintain their leg muscles, but they’ll still lose muscle mass for the muscles they don’t use. In other words, you need to exercise all the parts of the body you want to maintain. Of course, right? Because it’s never easy….