If you still doubt that exercise keeps you young, just look at Ernestine Shepherd, a 73-year-old bodybuilder from Baltimore, Maryland. I swear, that's a 24-inch waist and there's not an ounce of fat or sag anywhere on her.

And it's not just her six-pack abs, her perfectly sculpted back, or her powerhouse arms and legs, but her perfect skin, posture, and energy.

She wasn't always this way. She started working out at age 60. Now she runs 80 miles a week, bench-presses 150 pounds, does bicep curls with 20-pound dumbbells, and eats 1,700 calories a day of mostly vegetables and lean protein.

If this isn't inspiration to stay fit, I don't know what is.