Hype Fulfilled: Leon Marchand Destroys Oldest World Record From Michael Phelps


Although we saw this coming for the last year, it was still electric when Leon Marchand broke Michael Phelps‘s 400 IM world record on the opening night of the of the 2023 World Championships.

But Marchand didn’t just get under Phelps’ old record time of 4:03.84 from the 2008 Beijing Olympics, but he was under it by over a second, going 4:02.50.

Headed into the meet, Marchand’s best time was a 4:04.28, which was from the 2022 World Championships. That time was originally the second fastest time in history behind Phelps’ former world record.

In his race, Marchand was 0.26 seconds faster than Phelps’ record on fly, and nearly three seconds faster on breast. However, he was slower than Phelps on back and free. Compared to his previous best time, he was nearly a second faster on fly and over a second faster on backstroke.

Splits Comparison:

Leon Marchand, 2023 World Championships Michael Phelps, 2008 Summer Olympics Leon Marchand, 2022 World Championships
Fly 54.66 54.92 55.54
Back 1:01.98 1:01.57 1:03.12
Breast 1:07.64 1:10.56 1:07.28
Free 58.22 56.79 58.34
Total 4:02.50 4:03.84 4:04.28

This June, Phelps became the longest-standing world record holder in an event with his 400 IM. In total, he held the world record for 20 years and 342 days. His world record time of 4:03.84 had also been the oldest long course world record in swimming. Now, that title belongs to Paul Biedermann’s 400 free world record.

Phelps had been in the NBC announcing booth with Rowdy Gaines when Marchand broke his record. He also presented the 400 IM medals afterwards.

Watch the race video here via NBC:

Watch SwimSwam’s reaction video of Leon’s race here:

In This Story

Leave a Reply

Notify of

oldest most voted
Inline Feedbacks
View all comments
2 months ago

I’m sure it’s been said before but Phelps record was super suited which is why it makes this record that much more special. The margin was akin to when Biederman body length best Phelps to break the 200m world record

tea rex
2 months ago

Celebrity doppleganger: Will Poulter. comment image&q=60

2 months ago

And it can go lower

2 months ago

Sub 4:00 is definitely within striking distance. You can see the talent, how long and comfortable he looks in the water, and it’s hard to imagine that the underwater as could get much better, but no way his individual strokes (freestyle and backstroke especially) aren’t going to improve considerably with more training, refining of technique, and experience. Remember how Phelps looked in the water in 2002 with his 4:11, and compare that to 2008. And if ever there were a coach whose forte was long term planning and execution, it would be Bowman. Scary to think, but Marchand could really just be getting started. To me at least, this does not look like a peak performance.

Eric Angle
Reply to  EastBingleton
2 months ago


When Phelps broke Dolan’s 400 IM WR, a WR that stood in the 4:11-4:12 range for a decade prior, would anyone have believed he could lower it by almost 8 seconds (7.92 to be exact) over the next six years?

Phelps recalibrated what we thought was humanly possible in this and other events, and there are a lot of reasons to think Marchand will do the same.

He and Bowman surely have their sights on sub 4:00.

Last edited 2 months ago by Eric Angle
Swimswam follower
2 months ago

Love reading your insights.
You’re missed. I’m sure you’re ecstatic right now. I am.

Ex-NC Lurker
2 months ago

If Marchand drops a 4:05-4:04 on the Pro Series next year, he’s going a 3:59-low in Paris.

2 months ago

Carson Foster is the new Laszlo Ceh , super elite swimmer ,but the chosen one swims the same events

Reply to  Stam87
2 months ago

His best shot at gold is surprisingly the 200 back which might be his 4th best event overall

Reply to  Facts
2 months ago

Yup kids 10-20, focus on the 200 back because the IMs have a king for the next decade

2 months ago

The second half of Marchand’s breaststroke leg was incredible. His split for the second 50 (33.77) was faster than for his first 50 (33.87) and 1.5 seconds faster than anyone else in the final (next best: Kalisz at 35.27).

About Yanyan Li

Yanyan Li

Although Yanyan wasn't the greatest competitive swimmer, she learned more about the sport of swimming by being her high school swim team's manager for four years. She eventually ventured into the realm of writing and joined SwimSwam in January 2022, where she hopes to contribute to and learn more about …

Read More »