With the Tour de France underway and the Olympics just around the corner, there's been renewed focus on some "older" athletes such as cyclist 39 year old Mark Cavendish and champion gymnast Simone Biles who is 27 respectively, would once have been considered well past their competitive prime.
Instead of retiring many older athletes are still managing to compete and win at the highest levels of their sports.
For a closer look at how this is possible KCBS Radio's Liz Saint John spoke with Doctor Nirav Pandya , Professor of UCSF Orthopedic Surgery.