Your bones are a powerplant for generating new cells. In many situations stem cells can follow more than one path to become whatever the body thinks is needed most. Some stem cells in bone can become fat or they can become new red or white blood cells. A new study demonstrates that laziness breeds fat, and aerobics is a powerful stimulator of new blood cell formation.

Your blood cells are in a constant state of turnover. Making new ones is a good idea if you want to be healthy. Your body is made to be used. Thus, using it stimulates the process of red and white blood cell rejuvenation. Not using it causes fat to accumulate in your bones and gunk up these important rejuvenation processes. Being a couch potato provides no value to the quality of your health.