Most Improved Iowa Boys 400m Marks Compared to 2025

May 01, 2026

This content requires a MileSplit Pro plan.
Join Now and select any plan for instant access!

MileSplit Pro Join Now

Improvement Rankings: Top Iowa Boys 400m marks compared to their season’s best performances from 2025.

Most Improved - 400 Meter Dash

Comparing 2026 season to 2025 season

Rank	Improved	Athlete/Team	Class	2025 PR	2026 PR
1	-20.64	Karsen Johnson Clarinda High School	2027	1:40.44	1:19.80
2	-15.12	Blaise Echevarria Southwest Valley High School	2028	1:21.71	1:06.59
3	-11.82	Nolan Randall H-L-V High School	2028	1:16.07	1:04.25
4	-11.07	Nate Doig Marion	2028	1:11.27	1:00.20
5	-10.79	Aiden Carter Centerville High School	2028	1:13.80	1:03.01
6	-10.41	Spencer Goe...