I hate running.
I prefer water, I can swim 500's all day long.
i have done 6 iornman races when i was a full time lifeguard, trainings a bitch sometimes but a wholelot of fun, up at 3:30 train, catch a surf, coffee, open beach by 6, surf every so often during day, long surf at 6pm when beach closes, eat, train from 8 until 10 crash and do it again 2 rest days a week. all day doing something thats why im fit as a fiddle now.
Iron man races are like triatholons i guess
my local race every year is:
23km surf ski
6km paddle board
it does differ with the different races, the pros do it longer.