2024 Speedo Summer Championships
Men’s 400m Individual Medley – finals
- World: 4:02.50 – Leon Marchand, FRA
- American: 4:03.84 – Michael Phelps, USA
- US Open: 4:05.25 – Michael Phelps, Club Wolverine
- Jr World: 4:10.02 – Ilia Borodin, RUS
Podium:
- Rex Maurer, UNAT – 4:13.17
- Ryan Healy, MICH – 4:18.94
- Jake Magahey, SA – 4:19.69
- Levi Sandidge, KYA – 4:20.43
- Ryan Merani, KYA – 4:20.90
- Grant Sanders, FAST – 4:22.41
- AJ Robinson, AGS – 4:25.79
- Luka Mijatovic, PLS – 4:25.97
Rex Maurer, officially swimming unattached but sporting a Texas Longhorns cap, ripped a 4:13.17 in the 400 IM final at the 2024 Speedo Summer Nationals to become the 21st-fastest U.S. performer of all time.
It was a huge swim for the 19-year-old, who is transferring to the University of Texas in August after having spent his freshman year at Stanford. Maurer’s lifetime best coming into the meet was a 4:19.10 from last summer’s 2023 TYR Pro Championships in Irvine. And that was a PB by 3.4 seconds, as he had come into the meet with a lifetime best of 4:22.51.
This year, swimming in the same pool, he clocked a 4:18.72 in prelims and a 4:13.17 in finals, crushing his old personal record by nearly 6 seconds. In the last 12 months, Maurer has dropped 4.14 on his breaststroke leg and 1.85 on the free, while the front half of his race has remained more or less unchanged.
| 2023 TYR Pro | 2024 Speedo Summer Champs prelims | 2024 Speedo Summer Champs finals | |
| 50 | 26.75 | 26.86 | 26.66 |
| 100 | 57.37 (30.62) | 58.04 (31.18) | 57.19 (30.53) |
| 150 | 1:30.10 (32.73) | 1:31.40 (33.36) | 1:30.01 (32.82) |
| 200 | 2:01.94 (31.84) | 2:04.17 (32.77) | 2:02.00 (31.99) |
| 250 | 2:40.79 (38.85) | 2:41.27 (37.10) | 2:39.21 (37.21) |
| 300 | 3:20.30 (39.51) | 3:19.37 (38.10) | 3:16.22 (37.01) |
| 350 | 3:50.41 (30.11) | 3:49.23 (29.86) | 3:45.29 (29.07) |
| 400 | 4:19.10 (28.69) | 4:18.72 (29.49) | 4:13.17 (27.88) |
Maurer will move to Austin in August, where he will join some of the best IMers in the world training with Bob Bowman.
All-Time U.S. Performers
| Rank | Time | Swimmer | Age | LSC | Team | Meet |
| 1 | 4:03.84 | Michael Phelps | 23 | MI | Unattached | 2008 Olympic Games |
| 2 | 4:05.18 | Ryan Lochte | 27 | FL | Daytona Beach Swimming | 2012 Olympic Games |
| 3 | 4:05.90 | Chase Kalisz | 23 | GA | Unattached | 2017 World Champs |
| 4 | 4:06.56 | Carson Foster | 21 | OH | Mason Manta Rays | 2023 World Champs |
| 5 | 4:06.96 | Tyler Clary | 20 | MI | Club Wolverine | 2009 Summer Nationals |
| 6 | 4:09.22 | Jay Litherland | 23 | GA | Dynamo Swim Club | 2019 World Champs |
| 7 | 4:09.55 | Bobby Finke | 23 | FL | Saint Petersburg Aquatics | 2023 Phillips 66 National Championships |
| 8 | 4:11.27 | Erik Vendt | 21 | US | Unattached | 2002 Summer Nationals |
| 9 | 4:11.45 | Kevin Vargas | 21 | CA | La Mirada Armada | 2022 Phillips 66 Summer Nationals |
| 10 | 4:11.46 | Charlie Swanson | 21 | MI | Club Wolverine | 2019 Pan Am Games |
| 11 | 4:11.66 | Gunnar Bentz | 21 | GA | Athens Bulldog Swim Club | 2017 Summer Nationals |
| 12 | 4:11.76 | Tom Dolan | 25 | US | Unattached | 2000 Olympic Games |
| 13 | 4:12.00 | Michael Weiss | 22 | WI | Unattached | 2013 WUGS |
| 14 | 4:12.48 | Alex Vanderkaay | 23 | MI | Club Wolverine | 2009 WUGS |
| 15 | 4:12.51 | David Johnston | 22 | CA | The Swim Team | 2024 World Champs |
| 16 | 4:12.58 | Jack Brown | 21 | AZ | Tucson Ford Dealers Aquatics | 2009 U. S. Open |
| 17 | 4:12.72 | Sean Grieshop | 19 | PC | California Aquatics | 2018 Summer Nationals |
| 18 | 4:12.92 | Robert Margalis | 24 | FL | Saint Petersburg Aquatics | 2006 Summer Nationals |
| 19 | 4:12.94 | Pat Mellors | 21 | AM | Jewish Community Ctr Sailfish | 2007 WUGS |
| 20 | 4:13.15 | Josh Prenot | 21 | PC | Unattached | XXVIII Universiade |
| 21 | 4:13.17 | Rex Maurer | 19 | CA | Unattached | 2024 Speedo Summer Championships |
