Born and raised in Calgary, Alberta, Riker-Fox started out his sporting career as a horse rider and a member of the Pony Club, until he began with modern pentathlon at the age of eleven, when he was truly inspired by the 1992 Canadian Olympic team.

Riker-Fox made his international debut in 2003, when he qualified for the Pan American Games in Santo Domingo, Dominican Republic, and finished seventh in the men's event.

Riker-Fox competed at the 2007 Pan American Games in Rio de Janeiro, and won a bronze medal in the men's competition, which gave him an automatic qualifying berth for the 2008 Summer Olympics in Beijing.

[2][3] Riker-Fox was selected to the national modern pentathlon team, along with his teammates Monica Pinette and Kara Grant, and made his official debut for the men's event at the 2008 Summer Olympics.

Despite his rough start in the competition, Riker-Fox accomplished a higher result by a Canadian male in an Olympic modern pentathlon, finishing in twenty-fourth place.