Everyone knows that professional wrestling is an incredibly tough sport on the performers, and any wrestler has a limited window in which they are at peak physical condition before it starts to catch up to them. Wrestlers are on the road up to three hundred days out of the year, and the constant travel can be just as exhausting as the in ring action. Compared to other sports such as American Football or mixed martial arts where athletes tend to retire in their mid-to-late thirties (although there are exceptions), many wrestlers keep going into their forties, fifties and even sixties. Wrestling is much more entertainment based than more legitimate sports, and sometimes its hard to walk away from the high of entertaining a crowd. With the success of NXT Takeover: R Evolution, and emerging main event stars like Dean Ambrose, Seth Rollins, and Bray Wyatt, the WWE is on the brink of a major youth movement. However, there are still many stars on the roster aged forty and over, and professional wrestling is starting to move past them. The older stars on WWEs roster are legends, and should be respected as such but theres a nobility in knowing when to bow out gracefully. Here are ten WWE superstars who should hang up their boots in the next year.