Take a look at the pictures of me and you will see that I'm of a fair complexion.

Eastern Daily Press: Mark Armstrong and wife, Alison, on the home straight at the Edinburgh Marathon. Picture: Edinburgh MarathonMark Armstrong and wife, Alison, on the home straight at the Edinburgh Marathon. Picture: Edinburgh Marathon (Image: Archant)

It basically means that myself and the sun are not a match made in heaven.

So when I lined up on the start line for the Edinburgh Marathon I had sensibly, to all intents and purposes, bathed in suncream.

What I didn't do, which was the polar opposite of sensible, was adjust my pace to take into account the conditions.

All my long training runs had been completed in pretty ideal conditions, temperature wise.

Eastern Daily Press: Mark Armstrong is tackling his second marathon in Nottingham this weekend. Picture: Edinburgh MarathonMark Armstrong is tackling his second marathon in Nottingham this weekend. Picture: Edinburgh Marathon (Image: Archant)

It didn't even occur to me to slow it down in the first half of the race on Sunday and I paid a very heavy price.

When will I ever learn my lesson about pacing?

I was cruising along in the first half of the race and felt good as I looked to close in on my goal time of around four and a half hours.

However, I took a walk break at the halfway point to eat a bit of an energy bar and from that point on it all went pretty wrong.

Eastern Daily Press: The 'Kids Kilometre' was the highlight of the weekend with daughter, Lara Armstrong, completing the race.The 'Kids Kilometre' was the highlight of the weekend with daughter, Lara Armstrong, completing the race. (Image: Archant)

Not intentionally, I slowed down over the next couple of miles as the conditions took hold of me. By around the 15th mile I knew I was in trouble.

I was in desperate need of some water and during the next drinks stop I took on far too much in one go. Another mistake.

Feeling in desperate need of a pick-me-up I took on an energy gel soon after. To say it didn't sit comfortably in my stomach would be putting it mildly – I now had some serious 'GI issues' to contend with.

I continued to plod along and took the decision that a stubborn little so-and-so like me thought he'd never take – I walked.

There were some people getting oxygen on the side of the course at points and I started to worry that I would be in need of some attention if I wasn't careful.

MORE: Five lessons in training for a marathonI was desperate to run but every time I started up a fresh wave of nausea would result.

I was done, desperate for the race to end – the problem was I still had around six miles to go by this point.

You might think that having already run 20 miles, another six wouldn't be too much of a problem but it still felt like a very long way to go.

My goal time of 4.30 had well and truly gone out the window – the only priority now was finishing. I was at the point where I didn't care what time – I just wanted it to be over.

My wife Alison, who ran the whole race with me despite feeling fresh as a daisy (this was her third marathon), kept me calm and ensured that thoughts of a DNF were kept firmly to the back of my mind.

It was only when I saw the 25 mile marker that I decided to give running another attempt, mainly because I couldn't bear walking through the crowds and I felt the least I could do for their support was muster a trot.

I've never been so glad to see a finish line and I felt quite emotional as I slumped to the floor. Not since I passed my maths GCSE have I felt quite so much relief.

I crossed the line in 5-25 – not a time that I'm proud of but it does at least leave plenty of room for improvement in the future.

Physically, my body had held up to the challenge – my knees that have been the cause of so much concern during my sporting endeavours – didn't let me down.

All those exercises in front of the television for the past few months every night had been worth it.

But the biggest lesson of all was how you must take into account the conditions on the day. You can't run at the same pace when it's 25 degrees than you can when it's half that.

So I'm left with a sense of unfinished business – I still want to tame the marathon beast after receiving a bit of a mauling from her. I've already started looking at which one I will book next but first I've got the Norwich 10K to think about in August.

But, for now, I can bask in the glow of being a marathoner – I just want to be a slightly quicker one next time.

Well done Lara!

Without doubt the best part of the weekend was running the 'Kids' Kilometre' alongside my daughter, Lara.

She is only three years old and her little legs found it difficult towards the end but she kept on running (unlike her old man in the marathon!)

She stopped at one point to do a bit of stretching, which was quite funny, and she also informed me: 'This is really tough daddy!'

But she kept going and the smile on her face as she received her medal was one of those moments you treasure as a parent.

However, the medal soon became surplus to requirements when she realised she also got a drinks bottle for completing the race...