Yep, that's right. On Sunday 24th April, I'm running the London Marathon. 26.2 miles.

A year ago I couldn't run 26.2 metres. Why am I doing this? Because I needed something to kick myself into shape.

Any normal person would maybe sign up to a 'Couch To 5k' or a fun run – but no, not me! Never one to do things by halves, I eagerly applied last August for a charity place in the Virgin London Marathon 2016 – there's no time like the present.

I knew if I was going to take on a challenge as huge as this it would be for a charity that had a personal meaning to me, so I wanted to run this marathon for Alzheimer's Society. Alzheimer's is a heartbreaking disease that has sadly affected some of my nearest and dearest. If anything is going to push me through those last grueling miles it's the knowledge that this pain is all for a great cause.

And so my marathon journey has gone a little like this. Prepare to lose some toenails people.

October 2015: Getting to grips with the idea of 'THE MARATHON'…

I was still in denial about the whole thing. How far is 26.2 miles really? That's like 20 times to and from the tube station, right? Apparently not.

I knew initially I had to break this down into manageable chunks to feel fitter. Before the hardcore running took place I had to at least make it up and down the (very steep) steps of my house without feeling breathless. Step one, complete.

Next I had to take part in our Wednesday #ELLEfit lunchtime runs. I've been very lucky that Team ELLE are an extremely active and supportive bunch – we even have our very own qualified yogi [Associate Editor Fern Ross] and usually there's always someone who has taken on a much crazier challenge, like our Managing Editor Debbie Morgan's 50k challenge in 8 weeks.

My advice: surround yourself with positive people. The best quote yet is from my friend, ELLE's Fashion Assistant Billie Bhatia: 'You run, I'll follow you in an Uber and shout words of encouragement. Then we can carb-load together.'

November 2015: Just keep running…

I looked into running programmes and schedules before I started training but I thought how hard can it be? Just start pounding the pavement and keep adding the miles on.

I attempted an early morning run first. I just woke up and headed out without eating anything. When I became slightly delirious and almost fainted I realised maybe morning running wasn't for me.

Night-time it was then. I actually enjoyed running in the dark. You have no choice. Also, embrace the weather.

My advice: Look at guides and plans for running, but remember you don't have to stringently stick to it. Just keep in mind how much you should realistically be training and work around that.

December 2015: None of the gear and no idea…

Things started to get a little more serious. I managed to hit those three and four mile markers comfortably but I started to get a few niggles in my shins, and so I was advised to go for a run analysis.

I would highly recommend that this is the first thing you do if you are considering running the marathon. It's vital to protect your feet/knees/hips. 

They analyse your running technique and will be able to tell if you over-pronate or heel strike and can advise you on the best trainers.

Most importantly, invest in a sports bra and socks.

In addition to running, I decided to mix things up a little bit with the cardio as running on your own can be lonely and feel a little monotonous. 

I've really enjoyed BOOM Cycle spin classes with ELLE Fitness Editor Muireann Carey-Campbell (AKA Bangs) and I live by her mantra, 'Grab a drink, towel down, fix your hair.'

Also, we tried boxing with Cathy Brown at the Third Space gym in Soho.

January 2016: Mind over matter….

It's cold, it's dark, it's after Christmas, all the rubbish Celebrations are left in the tin and running can get a little bit boring.

Thankfully I found new inspiration via Bangs when she came into the office and gave an inspiring talk. In no time at all she had me fired up and ready to hit the road again.

This marathon has been much more of a mental challenge than a physical one.

You begin to formulate little goals: 'Just make it to the next lamp-post. For god's sake, don't let that man lap you AGAIN. Think of all the carbs you can have after this, chocolate pudding, chocolate pudding.' And then of course there's the reason you started it all to begin with – to achieve what you initially thought was a ridiculous goal.

February 2016: Racking up the miles…

The great thing about running is you can do it anywhere.

Initially I ran with music but I quickly realised I was trying to run to the beat and Justin Bieber and me weren't syncing. I wasn't concentrating on my breathing and my pace, so I stopped.

I actually really enjoy having some 'me time': a bit of space with my own thoughts. Before you know it, that's three miles done, six miles done, nine miles, 11 miles… ouch! This is going to hurt in the morning.

This is me after a 14-mile run, questioning life and wondering how on earth I'm going to do a extra 12.6 miles on top of that. 

On the plus side, I can't believe how much I'm eating and not pilling on the pounds!

March 2016: The big run

I have learned a lot about my body and how far I'm able to push it.

I was very lucky that my boyfriend joined me for my last long run. While it was great to have some company (and a pretty fast pacemaker) the best part was he brought out the competitor in me – he wouldn't let me stop.

I ran to the stage where I couldn't feel much and at one point I think I might have said, 'I feel like I'm having an out of body experience'. My legs were still moving but I was no longer thinking about running - the miles rolled into one another. I had ran 19 miles. 19 bloody miles.

 April 2016: The Paris Marathon

Three weeks before my race, my boyfriend ran the Paris Marathon.

This did NOT help my nerves. I was an emotional wreck on the morning and after seeing people pass out and collapse at the finishing line, I wasn't filled with confidence. I suddenly felt panicked. 'You've not done enough training', 'What if I hit the wall?', 'What if I collapse on the street?! 'It's too late now, Catherine!'

One week until D Day and of course I get hit by a cold and strain my knee. With Vicks inhaler as my new best friend and some fantastic physio I'm on the mend. This will not get the better of me. If I've gone through all of that then I can definitely fight off this.

My marathon training has been one heck of an emotional journey but I've loved it. I have faith in humanity again and I can't wait for the atmosphere and support from my family and friends on the day.

I've lost some weight on the way (and a toenail) and pushed my body to new extremes, but most importantly I've almost reached my target for a very worthy cause and hopefully made my grandma proud. This one is for you.

Wish me luck, and have a G&T waiting for me at the finish line.

The details:

 What: Virgin London Marathon

 When: Sunday 24th April

 Where: London

 Distance: 26.2 miles

 #oneinamillion

On 24 April history will be made as the one millionth London Marathon finisher crosses the world famous Finish Line on The Mall.

@LondonMarathon

Sponsor me here:

http://uk.virginmoneygiving.com/CatherinePykett