Hi. I’m running. I’m also telling some of my stem cells what to do right now. Well, I probably am, based on a new study with mice.

We have what are called mesenchymal stem cells. This type of stem cell goes on to become either fat or bone. Researchers found out that endurance exercise triggers the stem cells to preferentially mature into bone. And having more bone cells means improved blood production, which means a higher oxygen carrying capacity, and better immune reaction and better wound clotting. The research appears in the Journal of the Federation of American Societies for Experimental Biology, commonly known as the FASEB Journal.

Researchers at McMaster University in Canada had mice work out on a treadmill for about an hour three times a week. A control group of mice watched Matlock reruns. Well, they may as well have. They did not work out. And the mice that exercised had way less fat in their bone marrow cavities, and a big increase in blood cells in the marrow and in the circulation. I don’t like exercising. But I really don’t like fat in my marrow.