159. Your Three-In-One Walk | Stunning Science, Surprisingly Powerful

Three weeks ago, this series opened with a 70-year-old woman walking down a sidewalk, obviously confident: head up and moving with purpose. Our simple, immediate thought was “I hope that's me someday." We've since spent two full episodes proving that isn't wishful thinking. It's buildable. Today, we close the loop. Because there's one organ we've only mentioned in passing so far, and it happens to be the one this entire series is really about in more ways than one: your heart. I've saved some...