Finishing a marathon isn’t just an athletic achievement. It’s a state of mind that says anything is possible.

Paula Radcliffe
British World Marathon Record Holder

As a teenager growing up in South Wales, fitness did not feature in my life. My attitude towards exercising was that it was something I should do, rather than something I found particularly enjoyable.

Although I was a regular gym-goer, my running experience was limited. At most, I would run for 20 minutes on a treadmill and even that was interspersed with periods where I’d be walking. Nevertheless, I considered myself to be reasonably fit and was proud that I had some degree of discipline or, to be more accurate, more discipline than most of the people in my social circle at the time.

One day, a friend suggested that we should go for a short run. This was my first experience of running outdoors. I will never forget it. I could barely even manage to run for 10 minutes! From the moment I started, my internal monologue was going crazy: "This is painful. I can't breathe. Ah, cute dog. I wonder what I’ll have for dinner. It’s so cold. I’ll have pasta. I think I'm slowly dying." Initially, I focused on ensuring that running became a regular part of my routine. I ignored time and distance, concentrating instead on running from my front door to the first lamp post on my street. I built this up to the second lamp post and so on, until I could finally run three miles. As my mileage increased, my self-esteem rose.

In 2011, with the encouragement of a colleague and having built up my confidence through a number of small races, I entered the New York Marathon. Having completed the race, I was shocked by the sense of loss I felt. What would I do now? Where would I get the same sense of achievement?

The connectedness of thousands of people and being part of that amazing energy is the closest to a spiritual experience that I have ever had. In fact, in almost every race I have ever run, I have felt sudden tearfulness almost as an impromptu reaction from the enormity of the experience. This goes some way toward explaining why I went on to run so many more marathons. It's hard to articulate how running my first marathon fundamentally changed my life, although this is described in detail in my book, Big Steps, Long Strides.

Not satisfied with just completing the one race, I decided to continue running diverse marathons all over the world; many with friends, clients and colleagues. Within 10 months, I ran marathons across Paris, Berlin, Amsterdam, and many more. I even ran a marathon along the Great Wall of China!

My increased energy and overall sense of well-being has positively impacted every area of my life. I’ve run one marathon after another and truly feel that for most people and all things being equal, the only barriers to achievement are psychological.