Walker was a two-time National Champion for the Mules, once in the indoor heptathlon and once in the outdoor decathlon. He won eight All-American awards, four times in the multi-events, and four times as a member of the Mules 4x400m relay team. He is in the Mules all-time top-10 in nine events and second all-time at UCM in the heptathlon having scored 5,377 points. He is also second in the 110m hurdles having run 14.07. His 7,264 points in the decathlon are the fifth most in school history.