The Ultimate Swim: The 12,000 IM

The 12,000 IM. 3,000 yards of butterfly, backstroke, breaststroke, and freestyle. Has it ever been done? Frankly, should it ever be done? Alex Mathson, a senior at Carleton College, completed a 12,000 IM in the Carleton College Thorpe Pool on Thursday March 2nd 2017. It took him 2:46:58.78 to complete the ridiculous swim.

Each 3,000 yard portion of the individual medley took Mathson just under 45 minutes (Butterfly 42:23, Backstroke 43:09, Breaststroke 44:12, Freestyle 36:33). Occasionally, in the name of safety, he would stop at the wall to take a few swigs of Gatorade to keep his energy up. He never touched the bottom of the pool during these brief breaks to ensure he would not be disqualified. Mathson’s teammates traded off the roles of counting, timing, and cheering while he swam.

“I decided to do it because I had done a 3,000 straight butterfly before and figured that would be the hardest part of the 12,000”, Mathson reasoned when asked why he had even considered attempting a 12,000 IM. Andy Clark, head coach of the Carleton College men’s and women’s swimming and diving programs, called the swim “truly inspiring, very impressive, and quite utterly shocking that he swam so far”.

Have you seen any other swimmers try a historically, long swim such as this?

Check out the entire swim below.

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Liz Sands
7 years ago

This is a great accomplishment! Back before my senior year of college we did an age group team practice that started as either 40 x 400 IM’s or 80 x 200 IM’s – LONG COURSE. Half way the coach said we could finish with an 8000IM or continue with the set. Three of us chose the 8000 IM. Since that day I crowned myself the 8000IM world champion (tongue in cheek of course) and have laughed about it. No time or anything, but boy was it FUN!

7 years ago

That pool is awfully shallow at the start end.

7 years ago

Practice work outs that I’ve had… 15k every 4th lap was backstroke don’t know my time… timed 4K IM… don’t remember my time…. timed 10k yard swim. 1:58….. all of this was between the age of 13 and 16… a long time ago!

7 years ago

Don’t give my coach any ideas

Hoosier Swammer
7 years ago

The most impressive single practice I’ve seen is 30 x 1,000. Coach would let anyone who wanted to only have 1 practice on New Year’s Eve to try. If you failed, you still had to do the afternoon workout. I did not attempt, though I kind of wish I had.

7 years ago

Why is this the most hardcore swim? Wouldn’t a 20,000m IM be a lot more harcore, and a much more even number?

7 years ago

Our team does a 16,000 IM on Christmas break with no counter, no touching the bottom and all swimmers do it….

Brotherly Love Coach
7 years ago

I’ve seen Dick Shoulberg give longer warm downs. And, all 50 swimmers would race.