I was thinking the opposite way round, not what it takes to reach the top end but what it takes just to become a punter in sport defines it's toughness, otherwise you can make any sport as tough as you like to some extent. Take for instance surfing. I'm sure that surfing is fantastically tough, if you're fanatical about it. But for the average punter a days surfing seems to involve sitting on a beach talking bollocks, having a bit of a paddle and a wobble, going to the surf shop.
The drive back to London is probably the most taxing part
Made me laugh 🙂
TBH the punter who drives to the beach and does this isn't surfing – paddling out and sitting on your board is not surfing. To get to a good standard of surfing uusually requires lots and lots of practice because skill wise its a difficult sport and some people never progress beyond a certain point because they simply haven't got the balance, strength, power and coordination to do so. Its also surprisingly hard aerobically – to paddle out in anything over a head height swell is usually beyond most people. If you then factor in catching a wave and riding it back to near the beach and then paddling back again and repeating for 2-3 hours. then you can see that its a very good workout.
Of the other sports I've taken part in and are mentioned, I'd say gymnastics isn't particularly hard aerobically, but strength (to weight ratio) and skill levels are way up there – eg how many people on here can do a simple move such as a back somersault or a press to handstand?
Judo is a very skillful art, but unfortunately less so when it comes to the sport version, and is physically very tough particularly in training.
IMHO windsurfing is nowhere near as difficult as surfing skillwise but that may be because I tried windsurfing after I'd been surfing for about 7/8 years 🙂