WITH best-selling novels, huge international sales figures and a movie starring Colin Firth under her belt, Tracy Chavalier needed another challenge before she turned 50 – so she decided to run the London marathon, writes Georgia Graham.

During a run on Hampstead Heath last September Ms Chevalier decided it was now or never if she was ever to take on the big challenge.

She said: “I had a little list in my head of things I wanted to do before I was 50 – learn to ride a horse, go in a hot air balloon and run a marathon.

“They are all physical things because I seem to have got it into my head that the moment I’m 50 my body is just going to give in and I’ll collapse.”

Training since December 1, she has been slowly building up her runs and looking after her diet. Even a festive blow-out was out of the question.

She continued: “I was quite sensible about alcohol and food. In January I cut out alcohol and sweets altogether and it was really good.

“Before that I hadn’t really understood alcoholics who just don’t ever have a drink – I always thought ‘why can’t you just have one?’ But actually it is so much easier to cut out everything all together. So I am going to do that for March too.”

Although it was on Hampstead Heath that the idea of the marathon first appeared, Ms Chevalier fast grew out of the park as a running track.

She continued: “Trying to find the space to run 17 miles in training is actually a challenge.

“I run from Dartmouth Park to Regent’s Park and around central London, or along the Union Canal, or the Canal to Victoria Park. Sometimes I’ll go on the Parkland walk to Finsbury Park.

“But the Heath is where I do the smaller bits of training and I love it there. For hill running I’ve started to include the really steep one from Swains Lane up to Highgate Village which is really tough.”

All this work is not just because of the milestone birthday – raising money for a cause close to her heart, and central to her most recent novel, is also keeping her going.

She said: “It’s an awful lot of work just to do it if just for a personal reason; you need to have someone spurring you on.

“I have several friends who have had breast cancer recently and the heroine of my last novel set in Lyme Regis died of breast cancer so it was really on my mind.”

She hopes to raise a huge amount of money for the cause and has already reached collected more than �3,000 from her agent, publishers and friends.

“I decided on �20,000 as a figure to raise because my son’s old headmaster at Highgate junior school, Mark Jones, raised �21,000 and I thought if Mark can do it, so can I.

“Then I found out he raised �31,000 but I didn’t dare change my target – he’s got lots of happy generous parents donating to him. I’m not sure I’ve got as many friends and fans ready to give me that much money!”

o To make a donation, go to www.virginmoneygiving.com/ tracychevalier.