Member of UK Athletics International Group
Seb was English Schools Champion in 1972 and made his Great Britain International debut in 1976.
He competed in the European Championships in 1978 in Prague where he won Bronze in the 800m. In 1982 in Athens he won Silver in the 800m and in 1986 in Stuttgart he won Gold in the 800m. In 1979 he was the European Indoor 800m Champion and he finished 1st in the European Cup in 1979 and 1981.
Seb competed in the Athletics World Cup in 1981 and 1989 and finished 1st and 2nd respectively. At the Olympic Games in Moscow in 1980 he won Gold in the 1500m and Silver in the 800m a feat which he repeated in Los Angeles in 1984.