After ten weeks of training, last Sunday was the first time I’ve run with Brittany, who is my fundraising partner and also the wife of David, one of my best friends from school. It was also one of the worst running experiences I’ve ever had – not, I hasten to add, because of Brittany.

She wanted to do about 17 miles and I wanted to do 15, so she ran the two miles from her place to mine, accompanied by David on a bike. The sun was shining, there was a slight breeze – perfect for a long run. Bottles of Lucozade, ibruprofen pills, keys and cash all went into David’s bike basket and we were off. So far, so good.

And that’s went it started to go wrong. Less than a mile into the run, it became clear that the bike was built for style rather than substance. As Brittany and I powered up the long hill that leads to the top of Hampstead Heath, David had to get off and push. This held us up just enough to be annoying.

Then we arrived at a fork at the top of the hill. A fork that took us towards Archway and him to Golders Green. (I still stand by my claim that we gave the right directions, but it’s still too soon for the subject to be discussed openly.)

After a phone call David turned around to catch us up. So Brittany and I ploughed on, looking over our shoulders every five minutes. Half an hour later we called again. The first call went unanswered, as did the next and the next. It’s amazing how quickly knee pain disappears when you think that your husband is under the wheels of an articulated lorry. I was more concerned about when my drink would arrive.

To cut an even-longer story short, we didn’t see David again until we arrived back at their place, soaked to the bone and as cold as I have ever been.

You may remember – several hours ago, when you started reading this blog – that the weather was glorious as we set out. But as soon as we ran past Buckingham Palace, near the finish line of the London Marathon, the sky turned black. Within seconds we were drenched through and then hit by a freezing gale-force wind. The rain eased after ten minutes and the wind dropped but the damage had been done.

We took the shortest route through Hyde Park to get back to their flat where David, having got lost near the North Circular, had only just arrived. Tea and a change of clothes were gratefully received before I got a bus home.

It meant I only ran around 13 miles, so I need to pick up the slack this week. But having run in those conditions, I feel ready for anything.