She's become a poster girl for Organ Donations, now she's pushing herself to the very limits.
Kirstie Tancock, who just a year ago had a double lung transplant, is about to take on a 180 mile charity bike ride.
Accompanied by the doctors and nurses who helped keep her alive, the 22 year old will set off on the mammoth trip from the Royal Devon and Exeter Hospital to Harefield Hospital in London tomorrow (Friday).
Just 12 months ago Kirstie Tancock was recovering from a double lung transplant. She has Cystic Fibrosis and was on life support when the transplant literally gave her her life back.
It's almost impossible to believe seeing her today, and equally hard to keep up! Kirstie is in training for a marathon adventure.
She's cycling 180 miles over three days to get to the hospital where she had her transplant in London last year.
– Kirstie Tancock
I never thought I'd get a transplant so I didn't think I'd have to do it.
And I think everyone as soon as I came round were quick to remind me I'd made this promise, so I had to go through with it really!
With Kirstie on her journey will be her husband Stuart, and the doctors and nurses from the Royal Devon and Exeter Hospital who look after her.
I'm just grateful they've taken the time to do this as well as saving my life.
The journey so far has not been an easy one. Although she's been training, her new lungs have become infected and she's now suffering from problems with her kidneys associated with the transplant.
– Kirstie Tancock
I feel amazing. I feel fantastic, but there's all these technical issues that come up on the way with a transplant.
A transplant isn't a cure. I still have cystic fibrosis everwhere else in my body.
I've never breathed this easy. I've never had this much freedom with my life really.
And to add insult to injury, while out training this week Kirstie came off her bike and is now nursing various cuts and bruises.
Her drive and enthusiasm are inspirational as is her will to give something back. This cycle ride is raising money for Harefield Hospital and the transplant charity Live Life Then Give Life.
Money will also go to East Devon Cystic Fibrosis, which paid for much of the equipment Kirstie used before her transplant.
She's a living example of why that money is so sorely needed.
Watch the full report by our Health Correspondent Jacquie Bird below: