Whether because of old/current injuries, the general state of the body, or simple personal preference, a significant portion of the population isn’t going to be running sprints on a track. Maybe you hate it. Maybe it hurts too much, or you’re worried about throwing something out. Whatever the reason for your sprint abstinence, there are worthy alternatives to traditional sprinting. (This Mark's Daily Apple article was written by Mark Sisson, and is narrated by Tina Leaman)