Yesterday I decided I was going to get to one of the closer canals to where I live in East London, keep going straight until I couldn't any more, see where I was, maybe find a hot drink and come back. I thought it would be much more fun than knowing where I'm going or using a map. As far as it went I was right.

I left the trip until just after eleven, first joining my folks for the mandatory mother's day madness. I wasn't worried about getting cold - I've got my thick slinky black leggings, enough warm tops to make me look like the Michelin Man and some special flash cycling gloves I bought last winter. Enough to keep me comfortable while I enjoyed the exhilaration of self-made-speed, the normal canal obstacle course of people, dogs and litter and the really satisfying buzz of hard physical exercise.

My fingers started getting cold after about twenty minutes. But I was already nearly at the canal, don't want my bum getting bigger, don't like looking or feeling this unfit and I thought if I pushed myself I'd generate enough heat to warm them up again. It took quite a while to get along the canal to the Thames where; unsurprisingly, I couldn't go straight any more. Nowhere to have a drink and warm up without getting my bike stolen and probably getting mugged too, so I didn't stop. I could have gone home via Wapping and Canary Wharf but that's smelly and boring (mostly main road or motorway) so I decided to return along the same route. By the time I had come off the canal my fingers were hurting so much I was a little worried and spent quite some time cycling one- handed while rubbing them to stop the pain.

I like cycling Leytonstone High Road. It has interesting, slightly sordid shop-fronts, places serving food and drink from all over the world and a cycle lane that most drivers respect. It's still challenging (and therefore fun) because it's uphill, pedestrians view it as an extension of the pavement and busses ignore it completely. There's no need to hoard energy because it's not far from the flat and if I cycle hard enough I can beat any car going in my direction, which I love.

But this time I couldn't feel the handlebars, gears or brakes any more. I was getting a little worried about whether my fingers might suffer later. What price vanity? Today - frozen fingers! Or maybe I should say 'vanity - thy name is overconfidence' since I couldn't get back as quickly or generate as much heat as I thought, because I'm not as fit as I had assumed.

I nearly knocked over a neighbour in my rush to the front door and managed to get inside and remove gloves and jacket. But I had to wait several minutes before my fingers stopped hurting, a little more to unbuckle my helmet and even more before I could work the taps for a bath. Now I've bathed, made lunch and written some emails and my fingertips are still sending some interesting messages.