Hello kit, according to hastily drawn statistics and dodgy reporting I have found that it is claimed that for the great majority the fact that IM is an endurance race means little to before and after fitness and that people remain either active or not after Ironman depending on pre-IM behaviour.
If you ask about people who have long IM distance careers, they were probably already active people and remain active and fit even after IM is over.
I look forward to what the actual IM athletes in the forum have to say.