Brentford Docker Sandra Courtney will be competing in the London Marathon on 17 April, one of several runs she is doing this year to benefit cancer charities. In June, she will be one of thousands of women participating in the Race for Life in the Deer Park, Richmond. And only a few weeks ago she was up to her neck in ice and water as she completed the Tough Guy race, billed as the most demanding on Earth.
Sandra, 37, is a constant surprise, not least to herself.
She told us: 'I've been running for about two years so I'm a relative newbie and still learning.
'I'm not very fast and I hope to finish the Marathon in 4h 50mins. The training has been fun. I've been doing 40-50 miles a week, pretty much all river runs from Brentford Dock towards London - I made it to Vauxhall Bridge - or out to Hampton Court, which was my favourite because the sightseeing is fantastic.'
She has taken part in the Race for Life for the last four years wearing a badge for 'Kitty'.
'Kitty is the mother of my two best friends,' she explains. 'Sadly she passed away in January 2008. She battled cancer and so it's in her memory.
'I started out doing it on my own with my friends just coming to watch and hold my bags but then after Kitty died one of her daughters and her grandaughter joined me. This year there will be seven of us - both Kitty's daughters, her grandaughter and our three closest friends. It's great to have all the girls doing it with me. Running is part of my life but for some of them this will be their first ever event so I am really proud of them!'
Sandra, an office manager in Ealing, was a once a smoker and shows it's never too late to give up the fags and change your life.
'To begin with,' she says., 'I just wanted to raise some money for a Cancer Research so I did the Bupa 10k in Hyde Park. I didn't do anything else for a long time apart from the Race for Life 5k's and then started getting into it in at the end of 2008 with 10ks and then half marathons - and I haven't looked back since!
'I completed Tough Guy in January and to date that's the toughest thing I've done.'
Tough Guy's own description sums it up: 'The original and toughest test of its kind anywhere in the World. You will need every last ounce of mental and physical strength you can muster to rise to this challenge. Your fear of heights, tight spaces, fire, water and electricity will be tested to the max. Everyone bar the very toughest will be beaten.'
Sandra adds: 'Let's see how the Marathon compares! I've chosen MacMillan for my charity as they helped when my auntie and uncle passed away and so it is close to my family and friends heart.'
She reckons some people think she's mad.
'I work as an office manager for IVIS Group in Ealing and some of them doubt my sanity doing all these events but I love it and it keeps me healthy and happy. Some of them do some of the runs with me but as yet no one wants to join me for Tough Guy.
I have a race a month booked in for the rest of 2011 on top of my training mileage so that should keep me busy. I'm already looking at booking next year's events. It's all very addictive!!!'
If you want to take part in Race for Life with Sandra and her friends, email her at scourtney74@gmail.com.
Sandra has raised £541 so far!