Japan has produced an 80-year-old climber of Mount Everest, and it's a nation where every weekend you can see men in their 60s and 70s strapping on pads and helmets to play American football.

So it’s somewhat surprising that in a country so famed for longevity, and with an active and healthy elderly population, that the national sport’s governing body has a mandatory retirement age of 65 for all of its members.

Put another way, if Tom Cruise were a sumo stablemaster he’d have less than two years left before being forced to call time on his career — likely long before the famously ageless movie star stopped hanging off the sides of airplanes or riding motorbikes over cliff edges.