I always believed I would be one of those guys in my 60's doing an Iron man competition. I still have tremendous strength, stamina and drive but I would need to train for the event. I definitely use different muscle groups working construction. I just don't have the time to train because I work so much. My recovery time when I get injured is a little longer. I need to remind myself not to jump off of a 4-5 foot stair landing, it definitely makes my knees hurt for a week