A Sunday stroll
Arrive at the National Theatre on the South Bank at 1330. Despite the formidable heat in London (33c/91f) the place is thronging with people ready for Crusaid's annual Walk for Life fundraiser.

Hotties for people of all persuasions abound. DJ is playing a medley of tunes with the word walk (and derivations thereof)in the title: Bangles, Mellencamp, Aretha, Katrina and the Waves, Run DMC and Aerosmith of course, to name but a few, but no Nancy Sinatra or Johnny Cash, as far as I notice.

The appointed departure time of 1400 approaches and people make a last dash for the loo, eager to balance the intake and output of fluids correctly. Two o'clock comes and goes. Still, the collection of gay activists, charity workers, compassionate corporate teams (in t-shirts which delicately balance understanding and branding), and other concerned individual seem to be happy enough.

The compere keeps promising we'll be under way in "just five more minutes", but the DJ's run out of fresh tracks to play. Ignore Susanna Hoffs' advice. Emulating Egyptians for 10km is not viable.

Eventually, quarter of an hour late, the MC introduces the guest "stars" who are to cut the ribbon and start the walk. Sir Ian McKellen's place in history is assured and I'm suitably in awe of his presence. Dannii Minogue's presence is less inspiring, but I have a soft spot for her as Kylie's sister. AS for the others, we have a ghost of Big Brother past, Captain Jack from Doctor Who, and some bloke from Eastenders. Good job I'm here for the exercise rather than the autographs.

Finally, at 1417, we're sent on our way. But with thousands of people trying to filter out of the narrow exit from the National's square it is, as one wag observes, more like the shuffle for life.

The early going proves heavy as the crowds prevent me from setting my own pace. If there's one thing I hate, it's walking slowly. I have an optimum rate, and much below that I start losing my balance. But as we move past the tourist traps on Westminster Bridge, I get the chance to start cutting through the dawdlers.

Turning east onto Whitehall, I start getting into my stride. As we pass a protest outside Downing Street, a mother and son who'd obviously been at the front of the group are arguing about who was going to carry the child's silver scooter. There's about 9km to go. Will these people never learn?

Passing through Trafalgar Square, we turn down Northumberland Avenue towards Embankment. As we reach the north bank, a group of corporate girls enjoy a flurry of excitement.

"We're halfway there," says one, "that official lady just told me." I look at my watch. 1450. We've been walking barely half an hour. Either we're breaking records or these girls have a nasty surprise in store.

The Embankment goes by without much worthy of comment, although I notice more than a few fellow walkers taking a rest or grabbing an ice cream. Every now and again we pass the walk's stewards who greet us with varying degrees of enthusiasm, ranging from disinterest to a one-woman extravaganza of whooping, applause and encouragement for each participant who passes.

We cross the Thames for a second time, over Southwark bridge and back onto the South Bank, where the buildings are starting to provide a little more shade for the savvy to walk in. It's about this time that I notice I'm regularly trading places with a couple of girls, a veritable Little and Large. As patronising as this may sound, the big girl's pace and stamina are impressive.

Another volunteer, a lovely lady of Latin extraction, assures us we're over halfway by this point. It's good to know, but I think she's missed her cue. Wonder how the corporate girls are doing.

Then back across the Thames over Tower Bridge. This is the start of our trip back west. The heat's really beginning to tell now. I'm thirsty, in spite of the litres of water I've drunk, my legs are tired, and my eyes are stinging from all the sweat that's run into them.

But there's fresh impetus when the girls ask a volunteer how many people have already passed her. A couple of hundred, comes the reply. The girls seem surprised and a little disappointed that it's so many, but I'm quite pleased with my position - not that it's a race, of course.

My pre-race banana has worn off by this point, so it's time for number two as I approach Cannon Street and pass St Paul's. A cheery Irish fella assures us we've passed the three-quarter distance mark, another piece of good news.

And so it's one last crossing of the river, south across the Millennium Bridge. I still rue the day they decided to amend the architect's original plans and de-wobble it. The big girl gets caught among sloth-like pedestrians, and I make a little ground on my adopted rivals.

But then we all fall victim to the tourist traffic that surrounds Tate Modern and the Oxo tower, and hit much worse when we get to the charming wharf near Coin Street. Which just happens to be having its annual festival.

Can't really blame them, but with less than a kilometre to go, extra crowds and stalls to avoid are the last thing this walker needs. However successful this Walk for Life may have been as a fundraiser, the practicalities of the route seem to have been given surprisingly little thought.

Still, with the National looming, the finish line is in sight. Despite having lost ground to the girls around the festival, the celebratory balloon arch is a welcome reward.

My time? Two hours, 10 minutes. Not too shabby, especially considering the conditions and the cattle-run nature of the start. And confirmation that I've come home "well within the first 200" is cause for extra celebration.

But my journey's not quite over. It's off to Battersea Park (my first visit, and a pleasant surprise to find it beats Hyde Park - reminds me of Vancouver's Stanley Park, but with less ocean and mountain) to meet Thomsk, Josh, Jane and Thea, and finally relax.

As a result of the schlepping, I've managed to raise more than £400 for Crusaid to put towards various HIV and Aids causes, thanks in no small part to many of you.

I've been warned not to make a habit of it. Possibly good advice, but never say never again.