The New York Times health blog has a story today adding yet another reason for regular exercise: It's good for stem cells in your bone marrow. When I run, I'm not generally thinking about my bone marrow, I admit. But there are times when I'm thinking about fat (or rather, how much of it I want to eat later in the day), and it turns out those thoughts apply to my bone marrow as well as to other places.

From the New York Times: