As one of the world's greatest athletes Michael Johnson knows all about leaving a legacy.
The four time Olympic champion is back in London and I asked him what he made of the lasting effects of the 2012 Games in the capital.
He feels that is not necessarily an issue that the Olympic stadium in Stratford will be primarily used as a football ground and a new home for West Ham.
Michael Johnson is also familiar with another London stadium - Crystal Palace - where he once competed.
It faces an uncertain future with plans being drawn up that could see the famous venue demolished. Johnson - who founded his own training academy, Michael Johnson Performance, in 2007 - is in a good position to recognise the challenges that the sport faces.
Johnson was speaking at the Nolan Partners Sport Industry Breakfast Club.