Martyn Rooney made his Olympic debut at the Beijing 2008 Olympic Games, making the 400m final where he placed sixth.
He was also a member of the 4x400m team who, despite finishing fourth on the night in Beijing, were retrospectively awarded a bronze medal nine years later after the Russian quartet were disqualified.
A mainstay on the anchor leg of the Great Britain 4x400m relay team, Martyn won silver at the World Championships in 2009 and then bronze at the 2015 and 2017 editions.
He made his second Olympic appearance at London 2012 competing in both the individual and relay events, and finishing fourth again in the latter.
Rooney, a triple European champion, was selected for the Rio 2016 Olympic Games, finishing fifth in his heat before being disqualified as part of the British quartet in the 4x400m relay heat.