Find something you like to do, and start doing it regularly. Go hiking. Go swimming. Go to the gym. Go running. Find some people who play basketball, or ultimate frisbee.
I do ultimate. It's a lot of fun. It's good for people of all skill levels. And when I'm out of shape, on offense, I can let the others run down while I breathe in the back.
I only do it once a week because my legs are old. (OK, the rest of me is old, too, but the legs are where I notice it the next day.) But even once a week of intense (as intense as I can do) activity seems to be enough to keep me in moderately decent shape. And it's activity that I like. (And, as an added bonus, the read-and-react nature of the game is a complete mental break from coding.)
I do ultimate. It's a lot of fun. It's good for people of all skill levels. And when I'm out of shape, on offense, I can let the others run down while I breathe in the back.
I only do it once a week because my legs are old. (OK, the rest of me is old, too, but the legs are where I notice it the next day.) But even once a week of intense (as intense as I can do) activity seems to be enough to keep me in moderately decent shape. And it's activity that I like. (And, as an added bonus, the read-and-react nature of the game is a complete mental break from coding.)