Summer McIntosh On 400 IM World Record: “My Breaststroke Has Been Feeling Good Lately”


Swimming fans worldwide were less surprised with Summer McIntosh‘s world record-breaking swim in the women’s 400 IM on Thursday night at the Canadian Olympic Trials than they were when she took hold of the mark for the first time last year, but nonetheless, the performance still left plenty of jaws on the floor.

After knocking off Katinka Hosszu‘s standard of 4:26.36 from 2016 in 4:25.87 last year, McIntosh dipped all the way down to 4:24.38 on Thursday, becoming the fastest swimmer in history by nearly two seconds, going nearly four seconds faster than the next-best time a swimmer has gone since 2016 (Kaylee McKeown, 4:28.22), and putting her eight seconds clear of her closest rival for this summer’s Olympics this season (Katie Grimes, 4:32.45).

McIntosh was just under her world record pace through the halfway mark, but ran away from the world record line on the breaststroke leg, soaring to a 300-meter split of 3:23.43, nearly two seconds under her pace from the 2023 Trials.

Split Comparison

McIntosh, 2023 McIntosh, 2024
27.82 27.55
59.47 (31.65) 59.18 (31.63)
1:33.70 (34.23) 1:33.31 (34.13)
2:06.39 (32.69) 2:06.30 (32.99)
2:45.13 (38.74) 2:44.22 (37.92)
3:25.31 (40.18) 3:23.43 (39.21)
3:56.18 (30.87) 3:54.66 (31.23)
4:25.87 (29.69) 4:24.38 (29.72)

McIntosh gained 1.79 seconds on the breaststroke leg, and only lost three-tenths over the other three strokes combined to result in the new world record by a second and a half.

McIntosh said post-race that breaststroke has been an increased focus of late while training with the Sarasota Sharks under coach Brent Arckey.

“Usually breaststroke is the stroke that takes the longest for me to get going. And a few tweaks in my technique have helped,” McIntosh said. “I really had a lot of confidence in my training because my breaststroke has been feeling good lately. So it’s always good to see those little improvements coming to fruition.”

The four-time world champion spoke specifically on training under fatigue in practice, simulating what it feels like in the 400 IM when technique is the first thing to go on the breast leg when you’re really feeling the backstroke burn.

“It’s something you can’t really simulate unless you’re super tired, because 100 breaststroke in the 400 IM is one of the hardest parts of it,” she said. “So learning how to manage that and not breaking down my stroke is something that definitely has been a focus.”

Kylie Masse, McIntosh’s Olympic teammate in Tokyo who won the 200 back on Thursday, said what McIntosh is doing is probably underrated given how normal it’s become over the last few years as the teenager has emerged into a star.

“It sounds crazy, but I think every time she dives in the pool we’re expecting something spectacular because that’s just the type of athlete she is,” Masse said.

“I think people don’t really realize how special it is. Because it seems normal but she is an incredible athlete and I hope people can just recognize that and appreciate what they’re seeing.”

McIntosh has locked in three individual entries for Paris after winning the 400 IM, also slated to compete in the 400 free and 200 free after wins earlier in the competition. She’s scheduled to race the women’s 200 fly on Saturday and the 200 IM on Sunday.

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Anything but 50 BR
1 month ago

Amazing to see! I love watching McIntosh, especially in the IMs and 200 fly. It’s great news that she is improving her breaststroke, especially for the 200 IM in Paris. It’s still very much up in the air of course, and she could still get silver or bronze (being off the podium is looking less and less likely), but I wouldn’t be surprised if she actually wins it by 0.5-1 seconds.
I have no doubt she will eventually hold both the 400 fr and 200 fr records (even if it’s in 5 or 6 years), but I can’t help but wonder how much more likely she would be to win the 400 in Paris if she wasn’t focusing on… Read more »

Aragon Son of Arathorne
1 month ago

She’s going to be the first woman to break 2:06 in the 2 IM. Im a huge UVA fanboy but this girl is on a different level even than Kate or Alex.

Beginner Swimmer at 25
Reply to  Aragon Son of Arathorne
1 month ago

gonna terrorize the Hoos

Aragon Son of Arathorne
1 month ago

Insane. Didn’t I hear or read that she isnt fully rested for this meet? I know it is trials but she is so phenomenal that she can train hard through it and win.

1 month ago

Summer’s breaststroke improving is bad news for Kate Douglass, Alex Walsh, and Kaylee McKeown

Reply to  Eddie
1 month ago

This race in Paris will be SO interesting. I think A. Walsh will be first by a hair after breaststroke, but it will all come down to the last freestyle leg.

Aragon Son of Arathorne
Reply to  Alice
1 month ago

If Alex is only a hair ahead of Summer, she stands zero chance of running her down. Kate D is the only swimmer that can handle Summer in the free leg, and even that is a tall order.

Reply to  Alice
1 month ago

It’s Summer’s.

Aragon Son of Arathorne
Reply to  Eddie
1 month ago

Isn’t as fast at theirs, but you are right about that.

Viola Smiles
1 month ago

Summer is a star

About James Sutherland

James Sutherland

James swam five years at Laurentian University in Sudbury, Ontario, specializing in the 200 free, back and IM. He finished up his collegiate swimming career in 2018, graduating with a bachelor's degree in economics. In 2019 he completed his graduate degree in sports journalism. Prior to going to Laurentian, James swam …

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