King suffered from a sleepless night after selectors did not let him know of his inclusion in the British team for the Games prior to the public announcement. The selectors had previously informed him that he would find out the day before the announcement. He was named as a member of the British squad, after being the only British athlete to achieve the qualifying time in the men's 50 km walk. King is the first competitor in the event for Great Britain since Chris Maddocks who competed at the 2000 Summer Olympics. Prior to the Olympics, he underwent altitude training with other members of the British squad in the Pyrenees. In the walk, he finished 51st, posting the time of 4:15.05. On the final lap, he gave hi-fives to members of the supportive home-crowd and games makers. His was the last ranked result of all participants of the walk.