"Nothing breaks my heart more than seeing that person who's struggling to lose weight who thinks that they need to run 20 miles a week. They have no desire to do it, their knees hurt, they hate it, and they're not losing weight. And I'd like to say, 'Well, I've got great news for you. You don't ever need to run another step a day in your life, because there's no value in that.' "There is value in exercise, though, and I think that the most important type of exercise, especially in terms of bang for your buck, is going to be really high-intensity, heavy strength training. Strength training aids everything from glucose disposal and metabolic health to mitochondrial density and orthopedic stability. That last one might not mean much when you're a 30-something young buck, but when you're in your 70s, that's the difference between a broken hip and a walk in the park."