Whilst at Oxford, he pursued an athletics career and, in the 1954 Empire Games won gold medals both in the 800 m and the 1956 Melbourne Olympics, in the 800 metres.
Whilst at Oxford, he pursued an athletics career and, in the 1954 Empire Games won gold medals both in the 800 m and the 4x400 m relay. Johnson went on to win a silver medal in the 1956 Melbourne Olympics, in the 800 metres.