Swim of the Week is brought to you by arena, a SwimSwam partner.
Disclaimer: Swim of the Week is not meant to be a conclusive selection of the best overall swim of the week, but rather one Featured Swim to be explored in deeper detail. The Swim of the Week is an opportunity to take a closer look at the context of one of the many fast swims this week, perhaps a swim that slipped through the cracks as others grabbed the headlines, or a race we didn’t get to examine as closely in the flood of weekly meets.
Cypress Fairbanks Swim Club product Jackson Hartzler dropped a massive best time in the 400 IM during the preliminary session on Friday at the Winter Junior Championships – West in Austin, launching himself into the top 10 all-time in the boys’ 15-16 age group.
Hartzler, a 16-year-old Ohio State commit, clocked 3:45.02 in the heats, dropping more than eight seconds off his previous best time of 3:53.13 to claim the top seed into tonight’s final.
He set his previous PB at the same meet last year, where he finished 14th.
Split Comparison
| Hartzler, 2024 Winter Juniors | Hartzler, 2025 Winter Juniors |
| 24.57 | 24.17 |
| 52.94 (28.37) | 51.52 (27.35) |
| 1:23.65 (30.71) | 1:20.97 (29.45) |
| 1:53.63 (29.98) | 1:49.34 (28.37) |
| 2:25.69 (32.06) | 2:20.39 (31.05) |
| 2:58.18 (32.49) | 2:51.86 (31.47) |
| 3:26.84 (28.66) | 3:19.10 (27.24) |
| 3:53.13 (26.29) | 3:45.02 (25.92) |
The swim moves him into #9 all-time in the boys’ 15-16 age group, a massive leap after his previous best didn’t even have him in the top 100.
All-Time Performers, Boys’ 15-16 400 IM (SCY)
- Maximus Williamson, 3:39.83 – 2022
- Luka Mijatovic, 3:41.76 –2025
- Thomas Heilman, 3:43.63 – 2022
- Matthew Fallon, 3:44.08 – 2019
- Carson Foster, 3:44.16 – 2017
- Sean Grieshop, 3:44.45 – 2015
- Andrew Seliskar, 3:44.83 – 2013
- Curtis Ogren, 3:44.87 – 2012
- Jackson Hartzler, 3:45.02 – 2025
- Baylor Stanton, 3:45.39 – 2023
Coming into the meet, Hartzler had raced the 400 IM twice so far this season, clocking 4:02.53 in October and then 4:02.30 a few weeks later in early November.
His swim on Friday morning came after a breakout performance in the 200 IM on Thursday, setting back-to-back best times in the prelims (1:45.57) and final (1:44.49) to finish 3rd overall and take over 12th in the 15-16 age group all-time. Shareef Elaydi (1:43.82) and Ty Thomas (1:44.21), also both 16, went 1-2, moving them into 6th and 10th all-time in the 15-16 age group, respectively.
Hartzler will have an opportunity to go even lower in the 400 IM during tonight’s session, coming in as the top seed by more than two seconds over La Mirada Armada’s Anthony Dornoff (3:47.25).
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