He is currently National Director at the English Institute of Sport (Executive Information System ). Walker represented Great Britain and Northern Ireland at the 1984 Summer Olympics in the 110 metres hurdles. In 1992 however, he failed to make the squad for the 1992 Summer Olympics and turned to rugby union.
Walker holds the fastest non-winning time for the 200 metre hurdles.
At Cardiff in 1991, he ran 22.77 seconds into a 0.3 m/s headwind. As a rugby player, he played on the wing for Cardiff Reconstruction Finance Corporation. Walker made his Wales debut on 6 March 1993 in the five nations match against Ireland.
Walker was a participant in Catchphrase, a Welsh learning programme broadcast on Radio Wales in 2000.