THAT hurt, that really did hurt. The London Marathon isn't meant to be easy - no marathon is, that's why it epitomises one of the ultimate human challenges - but Sunday's race, held in extreme heat and humidity, was brutal.

A friend of mine collapsed 500 yards from the finish, and after four attempts to get up, was counted out by the St John helpers, who whisked him away to a tent, and then off the University College Hospital.

Temperatures hit 21 centigrade in the capital by midday, and what with the humidity it made for the toughest of running conditions.

For most runners they've trained on cold winter mornings and evenings, not in the unrelenting heat which poured over tired bodies.

St John Ambulance said it treated 5,032 people, and of these 73 were sent to hospital for further treatment.

I was just glad to get through it. I travelled up to London on the Saturday evening staying at an hotel next to Lambeth Palace along with dozens of other runners. A coach picked us up at 7.30am and took us to the race start. It took an eternity to get there and by the time we got to Blackheath I was seriously busting to go to the toilet.

What got me through the day is that I prepared myself for the heat. I'd brought suntan lotion, Vaseline and also taken some medication to get me through the race. Posey as it might have looked, I sported sunglasses for the first time this year.

I'd also worked out a drinks strategy to take water at every other station, and then to drink the special Lucozade drinks at every five mile drinks station - slowing to half pace to make sure I consumed the drink.

I also had my dad and girlfriend at various parts of the course armed with jelly babies, Kendal mint cake and an asprin!

That preparation was to pay off. I set off with Mary Picksley, a lady from Steel City Striders in Sheffield who I had met at a race in Lincolnshire in February who I could pace with. We went at a steady 7min 30 mile pace for the first 10 miles, and by Tower Bridge and half way we were through in 1hr 38min.

Mary started to struggle - she later told me she had problems with an Achilles brought on by wearing new socks she had bought at the London Marathon exhibition the day before - so I decided then to forge ahead. By 15 miles I was hurting. My legs were aching, particularly my hamstring and quadriceps. The pain was quite intense, and I knew the final 11 miles were going to be a challenge.

It was a case of sticking to the drinks strategy, digging in, and working the miles. The road soon became clogged up with walkers. The temptation was enormous to walk, but I didn't dare. I saw my dad at 20 miles and grabbed the bag of goodies, treating myself at every mile with a treat.

The wall of noise was amazing, especially running along the Embankment for the final three miles. My legs were screaming with pain, my body was aching, but I was going to nail this race.

I saw a friend of mine, Tex Dallas, at 25 miles near the House of Parliament. "Go Davey boy," he shouted, holding out a hand for a high five. That was it, that was the spur I needed.

I pushed on setting my goal to be inside 3hrs 30 minutes. As I entered Birdcage Walk opposite Buckingham Palace, I could see in the distance the clock just ticking over to 3:30 - but I had crossed the start line back in Greenwich well over a minute from the official start time, so I had 60 seconds to get inside the target time.

I put in a sprint and sailed past quite a few people, talking myself to finish strongly. I did so, crossing the finish line in an official time of 3hrs 29min 14sec for 3,226th out of more than 35,000 runners.

I was delighted. I was exhausted and quite emotional; emotional out of sheer relief. That was hard, wickedly hard, but my body was intact and I had survived to complete the next part of the challenge.