Cathy Freeman reveals her biggest regret after getting shock result on a DNA test - and gives Aussie Paris Olympians five words of heartfelt advice

Australian sporting legend Cathy Freeman has revealed her biggest regret following a DNA test that showed she is better suited to be an endurance runner than a sprinter.

Freeman, 51, famously won the 400m final at the Sydney Olympics in 2000 - but is now wondering what could have been if she'd contested the 800m.

'After retirement I realise now that I had a really big appetite for the 800m, so stepping to a two-lap event up from a one-lap event,' she told News Corp.

'I would have loved, loved, loved to have given the 800-metre [race] a real crack.

'I kind of have regrets I would say a little bit and I have never come out and said that publicly at all before, but I can own it now because it's in my DNA results.'

Freeman's win at Sydney Olympic Park on that famous September night in 2000 was impressive on many levels.

The pressure was immense, as the track star carried the hopes of the nation on her shoulders before she rocketed to victory. 

Speaking on Channel Nine's Today show on Wednesday, Freeman also had five simple words of advice for Aussie stars competing at the Paris Games: 'Never forget who you are.'

'[Also] Where you are from... or who you belong to,' Freeman told co-hosts Karl Stefanovic and Sarah Abo on Wednesday.

'I think that is really important.. it keeps you grounded....there is a lot of noise, excitement and emotion at the Games...it will make the journey a far more memorable one.'

Freeman later admitted the gravity of what she achieved at the Sydney Games will never completely sink in.

'[The] short answer is, no,' she said.

'I'm a bush kid, barefoot, wood and dirt girl but certainly all these years later, in my infinite wisdom, I certainly can respect the connection and the emotion that gets all flurried up in people's hearts and minds.

'It [competing as an Olympian] really is a gift... and when it came to the running, it was freedom — complete freedom for me.

'Athletes like myself kind of thrive on the Olympic environment to be truthful, we love it. Even though the pressure on me.... was full on.

'And for me it was a 17 year-lead in when you factor all the training and preparing, not just one lap of the track.'