Originally an amateur footballer, Keily served during the Second World War and, upon his return to England, was placed on the reserve list of his former team and never again made it to the field.

After unsuccessful appearances at the 1958 British Empire and Commonwealth Games and the 1960 Summer Olympics, he retired from active competition, but re-entered the sport at the master's level in the 1990s.

His career was interrupted by the Second World War when he enlisted with the Sherwood Foresters and fought in France and, although he soon returned to England after ending up on the sick list, he was placed on the reserves of his former squad and never again saw active play.

The fast start resulted in an eventual world record for winner, Ethiopia's Abebe Bikila, though Keily faded to place 25th in a field of 69 competitors in the marathon.

[2] During this period Keily also participated in twenty-one British national road relays, helping set new records in thirteen of them, but he retired from active competition following his sole Olympic appearance.