Sitting on the sidelines of a Saturday morning karate class, watching my sons having the time of their lives learning to kick and punch, joining in was the last thing on my mind.

As a mum of young boys, who seemed to have limitless energy, I was grateful for the rest, to be honest. But when the Sensei  - a superfit woman who was older than me - asked me why I wasn't giving it a go, I couldn't think of a good enough reason to stay in my seat.

I was fairly fit, having done Pilates and swimming for years, and the odd Zumba class, but martial arts? The idea of me - a mum in her forties, standing just over 5 feet tall - learning to karate kick and chop like Jackie Chan, was as my husband later admitted, rather hilarious.

Yet the following week, I found myself stumbling my way through my first kata - a series of moves, designed to hone specific karate techniques.

My entry into the world of karate coincided with me getting a literary agent for my first novel. I started writing after years of working as a journalist. Anyone who has been published will tell you, getting there is a long, hard slog filled with rejection and I'm no exception to this rule. I made a kind of bet with myself; could I get my first book published by the time I reached black belt level in karate?

At times I felt like giving up writing and on those occasions, having something else to focus on really helped. Months would pass as my book went off to publishers and there would be yet another round of "no thanks" letters. Karate taught me to have patience and I found that the criticism I got from editors was really useful to improve my writing. I opened my mind to learning  - just as I did in karate.

There were times when I would be really frustrated in karate, that I wasn't flexible enough or strong enough or I couldn't get a technique right but I kept working at it, training three hours a week. I applied the same persistence to my writing. I took the best character from my first book idea and I gave her a storyline all of her own. That book became the romantic comedy about motherhood, Mr Make Believe.

In the meantime, another opportunity came up  - to interview an ageing gangster and his family for a biography about their life of crime. This wasn't something I thought I would ever do but I took the chance and got a publishing deal with Panmacmillan. It was a completely different style of writing for me and a really big project - which was rather scary. Karate gave me the courage to face my fears and write the book. Coincidentally, around the same time, I got my black belt.

So, I actually achieved my karate dream before my first book was published in 2016 in the end but by then I was enjoying the journey. Five years earlier, when I started out, both of those goals seemed little more than a distant dream.

The best bit was that Mr Make Believe was picked up by Ipso Books and was published this year, becoming an Amazon Kindle top ten bestseller. Another book I wrote for Panmacmillan, Keeping My Sisters' Secrets, is now an international #1 bestseller, as well as appearing in the Sunday Times top ten paperbacks' chart, and it is still topping the Kindle charts in several categories. I have recently signed a two-book deal with Panmacmillan and my next book is due to be published in the summer of 2018. I also have another romance for Ipso Books up my sleeve, a comedy called Ten Easy Steps to I Love You, so watch this space.