Marathon world record-holder Paula Radcliffe told ITV News that she was "excited" to return to the Olympic Stadium, as thousands gather to take part in the National Lottery Anniversary Run.
Radcliffe thanked the British public and Olympic committee for "continuing to support sports".
The scene is set for today's National Lottery Anniversary Race, which is taking place at the Olympic Park in Stratford, east London:
Paula Radcliffe, who missed out on competing at the London 2012 Olympics due to injury, said she is "looking forward" to the National Lottery Anniversary Run later today:
Marathon world record-holder Paula Radcliffe will run the first event to be staged at London's Olympic Stadium since the 2012 Games later today.
Radcliffe, who was unable to compete at the London Olympics due to injury, will join a host of sporting stars including Olympic gold medallists Sir Chris Hoy and Victoria Pendleton, who are more used to cycling than running.
They will be among the 12,500 people taking part in the five-mile (eight-kilometre) National Lottery Anniversary Run, in which competitors will complete the final 328 yards (300m) on the Olympic Stadium's track.
Radcliffe has predicted the event would "recapture the spirit of the London 2012".
Sir Chris Hoy told ITV News Tour de France leader Chris Froome would be "frustrated" by the constant questions on doping but the recent scandal in athletics involving Asafa Powell and Tyson Gay showed the "testing procedures are working well".
He'll be frustrated by it. There's no doubt it must be incredibly frustrating. But his frustrations will be with the people who were cheating in the past not with people asking the questions, they have to ask the questions.
It's what the public want to know. They want to know is it possible? Are we looking at clean performances? Can we believe these current crop of athletes?
I like to think that with 99 per cent of them, you can. It is possible and yes there has been scandal in the last week with athletics and it is bad news for sport, for all sport but on the flip side think about the clean athletes.
At least they know they're getting the chance to compete on a level playing field, that the cheats are being caught. And it's a sign that the testing procedures are working well and there's nowhere to run - if you excuse the pun.
The Ministry of Defence has announced that Britain's most successful Olympian Sir Chris Hoy is becoming an Ambassador and Honorary Group Captain for the Air Cadets.
Last week the six time Olympic champion announced his retirement from competitive cycling.