Probably going to ruffle a few feathers here but I can't consider F1 racing a sport, and the same with golf. Just my personal definition, but a sport is a competition where you use your own physical ability to compete against others. In general, if you don't have to run (or an equivalent to running such as ice skating or bicycling), then it's probably not a sport in my book lol.
Sure the guys in F-1 racing are definitely in peak physical shape and they go through a lot of stress, but that doesn't automatically qualify it as a sport. Living on a space station requires peak physical shape but it isn't a sport. In chemotherapy one goes through hell in terms of stress, but it certainly isn't a sport.
Anyway I would say soccer is the most demanding sport. The tour de france and water polo are also up there.
