The Fountain of Youth may not be a secret watering hole in Florida where Ponce de Leon famously searched, but this remarkable demonstration of what exercise can do for a body may shed light on where it may be found.

It’s quite stunning to see that the legs of the athletic 40yo and 70yo look quite similar whereas the legs of the 74yo sedentary man are astonishingly different. In all the pictures, the white around the outside is fat. The bright circle in the middle is the bone marrow. The light gray is muscle tissue.

It’s readily apparent in the men that exercise that there is tremendous muscle mass compared to fat and in the sedentary man, not only is there more fat, but there is far less muscle.

This picture reminds me of seeing those lungs of smokers vs nonsmokers they show in high school health class.

Not sure about you, but it certainly makes me think twice about taking elevator instead of the stairs.

–Richard D. Thrasher III, MD