With my birthday looming at the end of July, I decided that I could either put on my slippers, sit in an armchair and lament the onset of middle age or put on my walking boots, get off to Snowdonia and try to convince myself that I was still young and fit - and raise some money for charity.

So, I decided to try the Welsh 3000s, the challenge being to be at the top of all 15 of the mountains over 3,000 ft in Wales within the space of 24 hrs without using any form of transport - see attached link for details http://www.welsh3000s.co.uk/.

The last (only) time I tried was with friends from university in the week between finals and graduation. We managed to pick the worst day of the week and completed the first leg in the small hours of the morning - in high winds and pouring rain. Given that the rest of the route passed by the house in which we were staying, we high tailed it down to the valley, cooked ourselves a hearty breakfast, and went back to bed!

This time, to spur me on, I asked people to sponsor me in support of The Shooting Star Children's Hospice. It is close to where I live in Teddington and provides respite and terminal care for children and young people who are not expected to live into adulthood. Sarah (my wife) and I did a 30 mile sponsored walk along the Thames for the hospice three years ago; it was hard going, so the prospect of a similar distance with added up and downhill caused me some trepidation.

My support team - Sarah, her parents and our two young sons - and I arrived in Wales on Wednesday evening (30 July), in weather that reminded me of my previous attempt.  The forecast for the following day, my birthday, was more of the same.  Still, I set the alarm for 4am just in case ...  I woke at 1am, having managed to get 3 hrs sleep - and spent the next 3 hrs listening to the rain hammering on the roof of Pen-y-pass Youth Hostel.  Spurred on by the generosity of those who had offered to sponsor me, and Sarah, who pointed out that this was the only chance I would get to do the walk this summer, I decided to give it until 5am to see if conditions improved.

Good news!  The rain had eased by 4.30am and I was on my way at 4.45am.  I was on top of mountain no. 1, Crib Goch, at 6.10am and up on top of mountain no. 3, Snowdon, in thick mist at 7.20am.  Not surprisingly, I had the summit to myself.  A long walk down by the mountain railway - as the weather improved and views to the sea began to unfold - and a steep descent off the ridge brought me down to the valley by 10am, where the support team was waiting with a welcome bacon sandwich and a change of socks.

A long flog up 2,700ft of grass slopes brought me to mountain no. 4, Elidir Fawr, just before noon.  The weather was still dry and bright (time for shorts!) and the rest of this leg across to mountain no. 8, Tryfan, was looking promising.  However, the weather closed in around 2pm, just as the route hit the rocky section of the Glyders.  Slippery rocks, two steep descents and a twisted knee made progress slow, and I arrived at the bottom of the next valley at 5.45pm, somewhat later than I had been hoping, to meet the support team again and pick Sarah up for the third and final leg.  Although the cloud level was still quite high, the weather forecast for the night was pretty bad and this didn't seem to be the best time or place for Sarah and me to attempt our first night hike ...  In any other circumstances, I would have called it a day.

Still, I was conscious of just how generous people had been so felt that I really ought to give it a try - my knee had eased and Sarah very bravely said that she was still up for accompanying me over the Carneddau plateau.  So, displaying an outer confidence that in no way reflected how I was actually feeling, I set off with Sarah for a slightly shorter flog of 2,200ft up mainly grass slopes, with a bit of light scrambling for added entertainment.  We made mountain no. 9, Pen yr Ole Wen, at 8.35pm.  No problems with the weather forecast this time - it was spot on and we "enjoyed" high winds and driving rain for the next 5 hours or so.

Navigating by map, compass and torchlight, we made slow but safe and steady progress to the refuge at mountain no. 13, Foel Grach at 3am.  With just over three hours left for the last two summits, we treated ourselves to an hour's break, before setting off again as it began to get light.  Relatively easy walking saw us up on mountain no. 15, Foel-fras, at 5.20pm, 23 hrs and 10 mins after standing on top of the first one.

If I'm not looking too elated in the photo, it's probably because I was having a Steve Redgrave moment, vowing never to undertake another 24 hr challenge walk in my life and telling Sarah that if she ever caught me looking at any guidebooks, then she had my permission to shoot me.  The four miles down to Rowen Youth Hostel were painfully slow - the emphasis being on painfully.  We arrived at 9.30am, somewhat to the relief of the wardens who had been expecting us to arrive in the small hours of the morning.

So, 3hrs sleep on Wednesday, no sleep on Thursday, 32 miles of walking, 11,800ft of ascent and descent, around 23 hrs between the first and last mountain, plus around a further 6 hrs to get onto the first and off the last - it's without doubt the most physically challenging thing I've ever done.  I'm not saying that I'll ever do - my Steve Redgrave moment was a distant memory by about noon on Saturday and I have to confess that I did have my guidebooks out and looked at a few websites to see what I might have a go at for my birthday next year (and in years to come)!

I had a fantastic birthday and, believe it or not, the highlight was the wind and rain swept night hike, as I'd never been on one before.  As I've said, I would never have started the walk in the first place and certainly wouldn't have kept going for the final leg, had it not been for the support of everyone who offered to sponsor me.  So, a massive thank you to all of you - and to Sarah, her parents and our two sons, for their help on the day.  The Shooting Star Children's Hospice is a wonderful cause, and I am very grateful to everyone for their support and generosity.