I did this on Tuesday and almost barfed:
200's. Start on 4:00, and every time you finish one, take off 15s rest. So the first one is on 4:00, second one on 3:45 etc. When you realize you wont make the next one, bump down to 150m, so initially you will get some rest, but every time you touch the wall you're still knocking off 15s. Do 150m's until you wont make your pace time again, then bump down to 100's. Keep going all the way through 50's and 25's. It's not fun.
I liked the look of this one, did it today at lunch. That was the entire workout other than 100 warmdown at the end,
first 4 200's were easy swim, 200 kick, 200 pull, 200 pull. after that all freestyle.
I was on the cusp of making the cutoff for the 200 on 2:30, so I switched to 150's there.
Good on ya! I only made it to 2:45, and even on that it was pretty much touch and go right in to the first 150.
So I did this today with some slight mods as the main set of a 5200 workout ...it went by really fast and was harder than I thought it would be given the large amounts of rest at the start of each new distance......The only change I made was to keep dropping the 15 seconds until I missed making the interval send off time....then straight into the new distance at the same interval with whatever I missed by eating into rest on the first set......so after missing the 200 on 2:30 (went 2:36).....it was straight into 150 on 2:30, 2:15..etc..... but first 150 was actually on 2:24 as I lost time on the previous 200....made the transition intervals really tough and gave a good balance to the generous rest intervals at the start of each new distance. I liked it! Thanks for the suggestion.