This book proposal is about older athletes who continue competing in sports well past typical retirement ages. While most athletes and people stop competing after college or high school, some defy expectations and set new records in running, triathlons, and other endurance sports well into their 70s, 80s or even 100s. These athletes stay physically active and fit, with sharp minds, by continuing their athletic pursuits later in life. They serve as an inspiration for healthy aging.