Good news for your mice

Will live longer than you.

Keep them on that little treadmill.

Researchers have found one more reason to exercise: working out triggers influential stem cells to become bone instead of fat, improving overall health by boosting the body's capacity to make blood. The body's mesenchymal stem cells are most likely to become fat or bone, depending on which path they follow. Aerobic exercise triggers those cells to become bone more often than fat. In sedentary mice, the same stem cells were more likely to become fat, impairing blood production in the marrow cavities of bones.

I didn't know I had mesenchymal stem cells. Maybe that explains that annoying itch.

"The interesting thing was that a modest exercise program was able to significantly increase blood cells in the marrow and in circulation," says one of the researchers. "What we're suggesting is that exercise is a potent stimulus -- enough of a stimulus to actually trigger a switch in these mesenchymal stem cells."

Can someone hand me the remote?