A few months before I was due to run my first marathon, I was at a book launch when the publisher, Laurain Day, approached me and asked if I'd consider writing a book about my marathon-running exploits. I laughed and told her it was best to wait and see whether I'd actually get round the bloody course before I contemplated writing about the experience and thought nothing more of it.

But then, after I had crossed the finish line of the Auckland Marathon in 2006, Laurain took me out for coffee and asked me again to write the book and this time I said yes. After all, the deadline was six months away, which was an eternity. I was running the New York marathon and surely there'd be stories from that to help me fill a book. So I blithely signed a contract with HarperCollins, bought one of those proper moleskin writers' notebooks that I would fill with marvellous yarns and pithy one-liners that I'd be able to pepper throughout my book — and again thought nothing of it. Until a few weeks before Christmas when Laurain rang to ask me how I was going with the book. "Ahhhhhh," I said. "The book ... the book ... yes, the book ..." I was sounding like a demented chook. "I thought I'd write it over Christmas," I said. "I'll be able to really craft it then — spend some time on it." Laurain was having none of that. She cracked the whip and used my Catholic guilt against me.

I locked myself away and within two weeks, I'd churned out Short Fat Chick to Marathon Runner — padded out with training tips from my running coach and mate, Gaz Brown, and stories from my fellow runners. Phew. The relief. Book written, job done. But as the date of publication loomed, I began waking in the night, rigid with horror. What if nobody bought it? What if it ended up on the table in front of bookstores with all the other unwanted books, marked down to 50c? It's all very well writing a book but until people read it, is it really a book?

HarperCollins had printed 8000 copies; that seemed an enormous number. As it turned out, I didn't have to worry. Despite the fact the book is no work of art, it sold and sold and sold and 10 years later, it's still being sold in bookshops. We're on our eighth reprint and so far, more than 30,000 copies of Short Fat Chick and the follow-up, Short Fat Chick in Paris, have been sold.

I'm proud of that. But I'm even more proud of the people who have used the book as a catalyst to do something amazing themselves. I've had more than 1000 emails and letters from people telling me the book inspired them and I can't count the numbers of people who've told me, at various running events, that the only reason they're on the start line is because of the book.

I've waxed and waned over the years when it comes to running. I've run Auckland, New York, London, Paris (twice, because it's so gorgeous) and Queenstown the year I turned 50, as well as numerous half-marathons. Which is all very well and good but in between marathons I balloon out to monumental proportions.

Running isn't a way of life for me; it's something I do when my favourite jeans don't fit. I enjoy running. And I enjoy the three months of early mornings, green smoothies and no alcohol I generally indulge in every year. But I also enjoy long lunches and gorgeous food and wine, so life has been a continual compromise.

To celebrate the 10-year anniversary of Short Fat Chick, Gaz and I are taking a group to run the Buenos Aires marathon. I haven't moved into training mode yet but I'm going to have to get cracking in the next month or so. And I will. I generally find the willpower to sort myself out in time to make it to the start line.

As a way of celebrating the anniversary edition of Short Fat Chick, I wanted to share stories from three runners, just a few from the thousands of people who've drawn inspiration from the book over years. They're a diverse trio, but they share a determination and a drive common to people who take on the challenge of running a marathon — and succeeding.

Tony Carter

Tony Carter's professional achievements are too long to list here but he was voted Chairperson of the Year in 2014 and chairs the board of Air New Zealand among many other successes. During his time as CEO of Foodstuffs, Tony was at a conference where I was the guest speaker. As part of my speech, I talked about running the New York Marathon. Tony had done a couple of halfs at that stage — albeit very, very slow halfs according to Tony. After I'd spoken, he walked out of the conference and said to his mate, "I'm on for running the New York Marathon if you are." His mate stubbed out his cigarette, shook his hand and said "I'm in." That mate lasted all of a week, but Tony thought "Stuff it. I'm going do it." And the New York Marathon was the first of 11 marathons that Tony ended up running.

"The pure challenge of running a marathon seemed really cool and I really did think that if you could do it, Kerre, I could do it!"

Until that conference and hearing me speak of the New York marathon experience, 42km seemed many, many steps too far for Tony.

"I remember doing the Auckland half-marathon and you come around that fork in the road where it says half-marathon this way, full marathon that way and I thought, 'There is no way I could ever take that left turn!' But eventually I did. When I ran my first marathon in New York in 2010, I ran it for charity, for CatWalk, and it provides that motivation to succeed. And when you've travelled all that way, you're not going to NOT do it. Failure was not an option."

You can understand how someone as successful as Tony would have had a few nerves at the start line of his first marathon. Plenty of his peers and business colleagues were aware of the challenge he'd set himself and for someone used to winning in life, it would have been mortifying to fail. There were a few wakeful nights before the gun went off at the start line of the New York Marathon.

"It's the fear of the unknown. Once you've done one or two, you know you're going to complete it. You just don't know how long it's going to take or how much it's going to hurt but deep down, you know you're going to do it. You know it's not impossible. That first one though ... that really is a leap into the unknown."

But crossing the finish line made it all worthwhile.

"It's that feeling of euphoria," Tony recalls. "It's true of all of them but I think the first one is even more special. It's just the most amazing feeling. I don't think you can ever experience something quite like that sense of pride in what you've achieved — balanced of course by the hell you've gone through to get it!"

Jan Taylor

A couple of weeks ago, Jan Taylor finished the White Marathon in Antarctica, becoming one of just 634 people able to claim a remarkable achievement: seven marathons on seven continents.

Jan's shelves are covered in finishers' medals from around the world. She has completed innumerable halfs, full marathons and ultra marathons and runs almost every day but 15 years ago, she was a different person.

"I avoided exercise most of my life," Jan says. "I struggled to walk to my gate, I was so unfit. I avoided going out with friends as I was so overweight. I couldn't even do up the seat belt — we had to get it specially lengthened."

Jan says her family was the catalyst for making changes in her life.

"I went for a walk up Mt Cook with my children and husband. Five minutes into the walk, I couldn't go on and had to rest while the family kept going. It was during this time I did a lot of soul-searching and realised my weight was impacting on the family and I decided I had to do something about it."

And she did. Jan signed up to Weightwatchers and became Weightwatcher of the Year in 2008. But she was advised that exercise was a vital component to a healthy lifestyle. And that's where Short Fat Chick came in.

"After reading the book, I was inspired by your honesty and the fun you had training for and running the New York Marathon and thought I would like to do the same. I rang Gaz to see if you might be taking a group back to New York, only to discover you were going to Paris. That was the incentive I needed as I'd always wanted to go to Paris. That was the start of running and travelling adventures around the world with my husband as one of my biggest fans and support crew."

Jan's still running today, finding it a great way to relieve stress and enjoy valuable alone time.

"I usually run on my own and I've developed a love of trail running in our amazing bush. It's great thinking time and I feel so much better after getting out the door and going for a run."

Vanessa

Vanessa's story is one of redemption. In 2010 and 2011, she was in a very dark place, serving time after committing a white collar crime. She decided, while she was in prison, that she would train for — and run — a marathon.

"We had a half netball court. I figured out the netball court must be about 90 to 100m in diameter — and I just started to map out the distance step by step. I figured if I ran around the court so many times, I could gauge the distance of my run. That's how it started. I just ran further and further each day. I'm pretty sure I ran a half marathon around the bloody netball court. I felt like one of those rats on a wheel but it was the only thing that kept me sane in that place."

I put it to her that the other inmates must have thought she was nuts.

"A lot of them wouldn't have understood," Vanessa concedes.

"I think they looked at me like I was mad, some of them, but no one gave me any flak for doing it. They just let me do my own thing. It was my way of showing my independence and strength, through keeping myself focused."

For Vanessa, running was a way of proving herself to the people who mattered to her most.

"I've always liked to think of myself as a goal-setter but I've never really felt like I've achieved much — especially going through that bad spell. Running was something I got back into while I was in jail and I just thought, 'Bugger it. I'm going to run a marathon.' I felt like I'd let so many people down in my life through what had happened at that time … redeeming myself is probably the best way to put it."

Once she'd done her time, Vanessa found a job working as a baker in Ruakaka. That meant getting up at 2am to travel from Whangarei to Ruakaka, working from 3am until 3pm, an hour's drive home again, a quick catch-up with her former partner, who worked the late shift, then around 5 o'clock at night, she'd start training for the marathon.

"I followed the plan in the back of your books Kerre — that's what I worked to. I thought well, if Kerre can do it, I can surely do it! I knew I was going to run a marathon, I just didn't know how I was going to do it. So I photocopied the plan you and Gaz had done from your books, modified it for myself and I hit the streets in the dark, in the middle of winter, clocking up my distances."

Her dedication and commitment paid off. In 2014, Vanessa became a marathon runner, crossing the finish line in a time of 4.29. Her family was there to cheer her home, and it was a very special moment for her.

"It was exhilarating. I had my [former] partner and my daughter there and I'm pretty sure I did burst into tears. That sense of satisfaction and accomplishment was overwhelming and they were so proud as well — I'm just about choking up retelling it. I felt like I had a sense of purpose again."

Vanessa went on to complete another marathon in 2015 but she stuffed her knee while doing it and now enjoys walking and short runs. However, she's on another mission. She's halfway through a BA, studying long-distance through Massey University.

"I'm majoring in clinical psychology and I want to complete my degree by the time I'm 50, which is three years away. And then, long term, I want to help women to reintegrate back into the community following their release from prison.That's my passion now."