[2][3] Competing at the 2023 USA Outdoor Track and Field Championships, in Eugene, Oregon, he reached the final of the 800m competition, where he finished fifth.

[4] was a gold medalist at the 2023 U23 NACAC Championships in San Jose, Costa Rica, in the mixed 4x400m relay alongside Bailey Lear, Caleb Cavanaugh, and Kiah Williams.

[5] In February 2025, he won the 600 metres at the Millrose Games in New York City in a meeting record time of 1:14.04.

His parents were also an athletes with father Brad and mother Tosha both being NCAA champions, and multiple-time All-Americans.

[8] In July 2023, Sumner announced that he was turning professional and had signed a sponsorship deal with Adidas.