Hardest Pool Event?

My answers have definitely changed over the years!

When I was an age grouper, we had an annual local meet called the Iron Man meet--it was a one session, timed finals meet and you had to do all the events, which consisted of the 400 IM, 200 free, 200 breast, 200 back, 200 fly, and 500 free. By the end of that session each year, the 500 was a brutal living hell and I'd consistently be well over 30 seconds slower than my typical 500 free. Besides that 500, though, I don't think any of the events I swam (everything up to the 500) was truly a *hard* event, though, whether SCY or LCM.

I know a lot of folks say the LCM 200 fly is one of the hardest, but when I was a teenager, I LOVED that race. I'd get in the zone and have the perfect body rhythm to be able to swim a very well split race and not die by the end...but now I'm certain that race would be a living hell for me.

I've got a jacked up breaststroke kick and correspondingly derive the majority of my power/speed from my upper body, so funnily enough the 200 breast kills my arms and chest but leaves my legs fresh and ready for more. I've certainly gone into fullblown vertical butterdie on the last lap or so of the SCY 200 fly when I've swum it without having trained for it, but when I actually train for it I enjoy the SCY 200 fly (haven't done the LCM one as a Masters swimmer, nor do I ever intend to do it again). I don't think the 200 free is a particularly hard event, nor are the 100s of any strokes. I've definitely died before on every single one of those at least once before, but that's more a problem of poor conditioning and/or poor race strategy than the races being inherently hard.

In my current stage of life, I'd say the 400 IM is the hardest, with the SCY 200 back a close 2nd. The 200 back is the only one where I've had to have help getting out of the pool after, as well as actually blacking out for part of the race (both happened in the same race at Nats in 2013 when I took it out only about 1 second off my 100 Masters PR at the 100 split while crushing the underwaters and then blacked out and have no memory of the race from the 125 turn through the 175 turn), but I'd say the 400 IM is physically close to as difficult while substantially mentally harder.

I can relate to the 400 IM. Have t done a lot of 200 backstrokes but my legs hurt the worse of any event after that one for sure. 

I can relate to the 400 IM. Have t done a lot of 200 backstrokes but my legs hurt the worse of any event after that one for sure.