In training
Nick Edmondson is running the London Marathon for Amnesty International

It's hard to put my finger on the moment when I decided to run the 2012 London Marathon.

It could have been when I crossed the line after my first half marathon and experienced a profound sense of satisfaction, but I was too busy stumbling aimlessly into a hedge to think all that clearly.

Whenever it was, I'm committed now. Last year I sat down and logged on for the marathon, signing my name to the challenge and setting myself a fundraising target of £1,800 for Amnesty International.

At first the training was easy. The race was ages away so popping out for the odd couple of miles' jaunt through the park was never too daunting. Especially when it was followed by a celebratory full English breakfast - I had earned it.

But as the weeks wore on, the running distances increased and the Christmas holiday overturned my training programme like a drunk uncle pitching over a buffet table, I found myself facing the harsh winter period with a serious amount of running to do.

One of the most unexpected problems with long-distance training is actually fitting it around day-to-day life. A serious run of more than 10 miles is going to take at least a couple of hours, which is a significant chunk of the after-work evening, especially if you have a commute home or dinner to cook.

You could always get up earlier in the morning but with nothing in your system and a seriously depleted sleep schedule, it feels a bit like stumbling home after a night on the booze.

I decided on a new tactic. I would plot a route and run home (in my case Shepherd's Bush in west London) from work (Canary Wharf). It seemed like the perfect idea. I would chalk up a significant run of more than 10 miles, avoid the temptation of coming home and reaching for the remote rather than the running shoes, and save myself a few pennies on transport.

So armed with a phone logged into Google Maps, a series of directions scrawled on my hand in Biro and an Oyster card (just in case), I set off on a new kind of commute.

Running through London - a few things I learned

  • London commuters want to get home or to the pub immediately and they are prepared to trample their own mother to do so. Running through the crowds is a lot of fun at first, looking ahead for gaps, weaving between people and generally escaping the bottlenecks but get in their way and you will feel their wrath.
  • The traditional comedic trope of a dropped banana skin has found a modern replacement in the KFC tower fillet burger. Somehow the union of chicken, hash brown and lashings of mayonnaise forms a dangerous piece of detritus completely free of friction. Step on one of these and you will be seeing stars.
  • Running the streets is a great way to see some of London's sights as well as gaining a perspective as to their whereabouts in relation to each other. Far too many Londoners are pushed around the depths of their city in trains without realising that a beautiful green space could be a short walk away.
  • A person talking on their mobile phone has no awareness of the world around them. If you are running and see one, take note. They could stop and turn at any moment. They are the human equivalent of a riderless horse at the Grand National with just as much ability to cause a pile-up.
  • People will smile at you if you smile at them. A simple point, but the endorphins of a good run can cause you to break the cardinal rule of London transport and actually smile at people as you pass. Some even smile back and cheer you on, which can be a real boost. Don't smile all the time though - the line between cheerful and unnerving is deceptively thin.
  • The comfort of your clothing is crucial. Anything that is rubbing slightly can turn into a colossal problem after a few miles. Not to mention the fact that you don't want to be left walking round the office like a cowboy in need of a horse the next day.
  • Every single other runner you see out there will look healthier and be wearing better gear. Try not to shout abuse at them as they spring past you like a lithe gazelle - you're only letting yourself down.

Despite a spot of confusion around Bank and a near collision with a Dominos delivery driver (watch those corners when you cross the road), I made it home.

Running through London is easier and more fun than it looks. It's a completely different beast to a weekend jaunt around the park and takes a lot more organising but it's a wonderful feeling to make it home and know that you've earned the right to collapse on the sofa.

To help Nick reach his £1,800 charity target visit his fundraising page.