The 400 IM has been placed at the top of our list for the most difficult swimming events for a few reasons. Firstly, is the amount of skill necessary in the IM races. Second, is the sheer effort required to complete the race. Lastly, is the fact that not only do these athletes have to complete the race, bu they have to swim it as if it were a 200 in order to compete.
The 200 Fly has been ranked second for one reason and one reason alone, the last 50. The 150 fly, while still being a difficult race, would not be ranked nearly as high if it wasn’t for that deadly last leg.
The Mental Strength and endurance needed not only to complete the race but race it for 15 plus minutes is quite impressive.
Sprint? Pace? The most awkward distance in the sport this event has become a sprint. Go out too slow and the race is over, go out to fast and you may not finish.
Legs. This race is all about the legs. Once you touch the wall the next most difficult event is being able to get out of the pool and walk over to your coach.