James O'Keefe, 58, is a cardiologist at Saint Luke's Mid America Heart Institute in Kansas City. A self-proclaimed "exercise enthusiast," O'Keefe says there was a time—decades, in fact—when he would routinely spend 2 to 3 hours a day running and working out vigorously. "I rarely took a day off," he recalls.
But if you see O'Keefe exercising today, you'll likely spot the MD on a post-dinner stroll with his family. He also enjoys practicing yoga, or doing some gentle backstrokes in the pool. (Try adding just 10 minutes of strength training a day with the Fit In 10 DVD and see results fast.)