By Marta Cooper

I love running. Of course I do, I wouldn’t be waxing lyrical for this blog if I didn’t relish in the sweaty cruise across the Embankment, jutting in and out of unassuming tourists with a mash-up of hip hop and Thin Lizzy for company.

Running has made me a better person. Compared to when I first dug out my trainers in 2008, I am happier, stronger, more relaxed. I smile more and moan less.

I think about running in three layers. The first layer is escapism: running a gentle 5k after a day at work is simply my time to relax and be alone. My only thought is reminding myself to stay light, stay engaged and keep moving.

The second layer is mental perseverance. In order to achieve goals, to run a certain distance or knock minutes off my previous time, I need to be strong mentally to lift and carry my body through the pain it will eventually endure. That focus, that process of powering through, can be brought to everyday life, from meeting deadlines to working through  personal problems. The only way out is through, as the saying goes.

Finally there is the deepest and constant layer of empowerment. The sense of achievement, satisfaction and pride through pushing yourself to the other side without relying on anything but your physical and mental strength is unparalleled.

Before you ask, yes running hurts. The burn of the last few hundred metres of a 10k makes a bout of dysentery I caught in southern China in 2009 seem like a spa day. But no achievement worth its salt comes without pain.

The natural high running triggers, like any narcotic, can become addictive to the point of dependency. Running has helped me in bleak times, so the ghost of guilt tries hard to convince me I have failed if my legs are heavy, if the twinges in my shoulders just won’t shake, if I can’t zone out and enjoy the kilometres ahead.

We’re not machines. Some days I will know from the get go that my legs aren’t up to the job; they are stiff, lead-like and would prefer spending their evening crossed on the sofa in front of mediocre cookery programmes. I adore running, but some days I simply don’t feel like it. Like with any love, a bit of time apart is not necessarily a bad thing.

The real challenge is balance: cherishing the run when you can do it, running the hell out of it and not belittling yourself when you can’t manage it or know you might not enjoy it that particular day.

It is hard to be mindful of this if, like me, you got into running to kick-start the arduous process of weight loss, when it becomes all too easy to see exercise as a necessary punishment for enjoying food. When I became more focused on exercise last spring after a back injury, working out five times a week at the expat gym near my flat in downtown Shanghai became a burden. I would justify meeting friends for cake or eating 2 RMB (20p) street pancakes for breakfast by taking my gym kit with me and burning off the approximately X calories I had savoured. I would often veto a banana for an apple (around 30 fewer calories).

Needless to say, I was hardly the most riveting of companions.

And, being someone who comes from an Italian family bound by the glue of having meals together, who relishes in baking and cooking for friends, I was hardly myself. The weight dropped off me, but so did any remnants of my personality.

I moved back to London last summer after two years in China. I had less time on my hands with a great job. I was reunited with a working oven I could bake in. I could run outside and not worry about getting an iron lung fitted. I stopped fretting about calories and focused on running and how it made me feel. I worked harder at it, I enjoyed it.

One autumn evening I bounced along the Embankment with a smile on my purple, sweaty face smeared with a day’s make up. My legs were moving, my hips were moving, my arms were moving. It hurt, but it felt incredible. I was strong, but light. The exhaustion was brilliant.

8 kilometres later I found myself sprinting down Fleet Street, the City suddenly bright under the grey sky. I was being carried by a force I didn’t know existed.

Me.

Marta Cooper is a journalist at Index on Censorship in London. She tweets at @martaruco