For every 5.5 miles run per week bone marrow becomes 1 year younger. This is done by gaining healthier marrow in smaller doses while running. Bone marrow is a semisolid tissue in the soft part of the bone that produces blood cells. Marrow produces red blood cells for the body. As the body ages it turns into yellow fatty marrow. This affects the blood and bone metabolism in areas such as pelvis, vertebrae, thighs, and hips in a negative way. It contributes to conditions such as diabetes and osteoporosis.
Running is not the only thing that produces this effect. Low bearring sports such as soccer, tennis, basketball along with high intensity activities such as jumping and volleyball create similar effects.
Secret: Running can increase the health of bone marrow.