Not An April Fools Joke: Summer McIntosh Swims 4:25.87 400 IM World Record


On the second last night of the 2023 Canadian Swimming Trials, Summer McIntosh swam to victory in the 400 IM with a 4:25.87, setting a new world record. This swim got her under Katinka Hosszu‘s time of 4:26.36.

Prior to this swim, McIntosh held the world junior, Canadian, and Commonwealth records as well, which she has now reset once again.

Splits Comparison

McIntosh – 2023 McIntosh – 2022 Hosszu – 2016
100 59.47 59.40 1:00.91
200 2:06.39 (1:06.92) 2:08.20 (1:08.80) 2:08.39 (1:07.48)
300 3:25.31 (1:18.92) 3:27.46 (1:19.26) 3:24.50 (1:16.11)
400 4:25.86 (1:00.56) 4:28.61 (1:01.15) 4:26.36 (1:01.86)

Before this swim, McIntosh’s 4:28.61 world junior record of 4:28.61 was the 4th-fastest time in history. She now has three of the ten fastest 400 IM performances in history including the first, fifth and sixth.

All-time Women’s 400 IM Performances

  1. Summer McIntosh – 4:25.87 (2023)
  2. Katinka Hosszu – 4:26.36 (2016)
  3. Ye Shiwen – 4:28.43 (2012)
  4. Katinka Hosszu – 4:28.58 (2016)
  5. Summer McIntosh – 4:28.61 (2022)
  6. Summer McIntosh – 4:29.01 (2022)
  7. Katinka Hosszu – 4:29.33 (2017)
  8. Stephanie Rice – 4:29.45 (2008)
  9. Katinka Hosszu – 4:29.89 (2016)
  10. Kirsty Coventry – 4:29.89 (2008)

McIntosh first broke the world junior record in the 400 IM with a 4:34.86 at the 2022 Canadian Swimming Trials. That swim came after she posted a 4:29.12 in March, which World Aquatics did not ratify. After her 4:34.86, she broke the WJR again at the 2022 Commonwealth Games in a 4:29.01 and then again in December 2022 with a 4:28.61.

McIntosh is a perfect 4-for-4 in terms of record-breaking performances at this meet. She started by swimming a 3:56.08 world record in the 400 freestyle on day one to take out Ariarne Titmus‘ 3:56.40. She then swam a new 200 IM world junior record with a 2:06.89 and another one in the 200 butterfly, posting a 2:04.70.

Race Video:

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5 months ago

Also posted after the 400 free : Summer is the bomb !

5 months ago

Summer is amazing!! I couldn’t accomplish that even in my wildest dreams lol Hope she keeps doing what she does best for as long as she enjoys it

5 months ago

Holy cow, i hope all those athletes does’nt read all the comments here. Can you just enjoy what’s hapenning for her…just stop arguing, there’s alot of jealousy here, it’s just reminds me when i was a teenager we were arguing on…my father is better than yours…no body knows the future…but there is a fact; there is not alot of athlete who already achieve what she did at 16 years old past or present…

Steve Nolan
Reply to  Daniel
5 months ago

They do, but they shouldn’t.

Mostly because we’re all very dumb.

The unoriginal Tim
5 months ago

OMG. I wish I could do that 🙂

Is 400m her sweet spot right now? The 400s are a touch better than the 200s this week. As she gets older and stronger we may see the 200s get even better.

At this rate she could hold 5 individual LCM WRs by Paris.

5 months ago

crazy. has anyone else ever held records in both 400s at the same time?

Grant us eyes
5 months ago

She brings North America up to the front by beating European and Australian women’s world record

Reply to  Grant us eyes
5 months ago

Lol a Canadian becomes a sensation and now suddenly its “North America”

5 months ago

Wonder what she can do in a 100 fly if she went for it. With her 26.8 first 50 of the 200 IM, she may be able to go out in a 25 high (with some more speedwork) and come back home in a 29 mid/high= 55 mid, something around there. Just of the WR, and compete for a gold medal in Paris. The question is just how would training for that affect her 4 Free, 4 IM races…

Tracy Kosinski
5 months ago

Summer doesn’t have to bring home 23 Olympic medals to become the best swimmer of all time.

There’s many reasons why she’s better than Phelps, Ledecky, Titmus, etc. for which we already know. There are many reasons to argue that she’s the best of her generation.

No one was surprised by her breaking the WR. We’re just ecstatic she’s done it so early in the year. Let’s be honest, the girl could get the 100 BR WR if she trained for it.

Right now, Summer McIntosh deserves to be celebrated and not picked apart.

Reply to  Tracy Kosinski
5 months ago

She has zero Olympic medals and you said she is better then Phelps lolol

Nada de Nada
Reply to  Joe
5 months ago

She is only 16! And is breaking world records. The medals will come and you will think about your comments.

Reply to  Tracy Kosinski
5 months ago

She’s 16 years old. How about you just appreciate her for what she is instead of trying to crown her the best of all time already?

Reply to  Tracy Kosinski
5 months ago

Let’s slow down just a minute. She is an amazing swimmer and likely will become one of the best of all time. But better than Phelps? Let’s have that conversation after 5 olympics, and 28 medals. Success and longevity equal GOAT status.

Reply to  Swim505
5 months ago

Yes and that’s why I think it’s not a fair comparison if you compared her with Ledecky and for sure she’s is more versatile and swimming in five different events and could win a lot gold medal but in terms of success , longevity and achievement right now , Ledecky has also already achieved the GOAT status like Phelps and also currently dominating in long distance events and doesn’t seems to be slowing down.

Cold Tub
Reply to  Tracy Kosinski
5 months ago

Well are you gonna list out the “many reasons” why she’s better than Phelps? Let’s hear them.

Reply to  Tracy Kosinski
5 months ago

☝️I’ll have what she’s having. ☝️

Reply to  Tracy Kosinski
5 months ago

Better than Ledecky and I don’t know if that’s a fair comparison to make because Ledecky only focusing on freestyles.

Reply to  Tracy Kosinski
5 months ago

This is definitely surprising and the entire swimming community is watching her. She is going to win 6 individual gold and 1-2 relay gold in Paris, and maybe she will break Phelps record to win 8 gold in one Olympics.

Reply to  JayZ
5 months ago

Which relay golds is she going to win in Paris?

Reply to  Sub13
5 months ago

Let’s be honest – none. That’s not a reflection on Summer, it’s just that Canada doesn’t have the depth the US and Australian women do. If Oleksiak doesn’t fully recover, Canada may even struggle for any relay medal.

Nada de Nada
Reply to  Tracy Kosinski
5 months ago

Agreed. She is the real deal…some might not like the fact that she is the best female swimmer on the planet at only 16! Swimming Queen….