That said; I am something of a forward planner. I do like my "to do lists" and when I turned 25 I sat down and wrote down a list of "30 things to do before I'm 30". This is not to be confused with a "bucket list". I don't have any morbid feelings that as soon as I turn 30 my life is going to be over. It just seemed a five- year plan was sensible at the time.

The list has changed and modified slightly over the years - I have come to terms with the fact that I probably won't master Mozart's Turkish March on my piano, and I've completely given up on trekking the West Highland Way (for now, anyway, as the last time I tried it, I got side-tracked and ended up going canoeing instead).

But there are several things I've managed to tick off too. I've had afternoon tea at The Ritz, Sunday lunch at The Ivy and dinner at The Savoy Grill (an alarming number of my goals did involve eating a lot). However, some of my goals were harder to reach - quite literally - but I struggled on and eventually got to the tops of Ben Nevis, Scafell Pike, Snowdon and Helvellyn and I've completed the Great North Run (twice).

And, yet, at the beginning of January, when I returned to my list, I realised there was one goal - a pretty big one in fact - that I had yet to accomplish. For some reason, which I still can't put my finger on, when I was 25 I said I wanted to run a marathon, and not just any marathon, but the Virgin London Marathon. As I turn 30 this year - on June 29, so feel free to pop it in your diaries so you remember my card - I knew I had to make a serious commitment if I was going to tick it off.

Now, I'm not a natural runner - far from it. Please don't assume that because I've done the Great North Run that I actually know what I'm doing. In all honest truth, I don't particularly enjoy running. But the Virgin London Marathon - much like the Great North Run - is such an iconic event that I would feel as though I'd let myself down if I passed on the opportunity to do it.

To give you an idea of just how much running is "not really my thing", it took me just under three hours to complete the Great North Run both times. Now, I realise, there will be kind people amongst you who will have read that and thought "so what?" and yet there will be others who will have sniggered at how slow that is. Even some of my colleagues struggled to hide their smiles when I told them and as several of them managed it in half that time, I can see why they find it fairly laughable.

I tried to convince myself that the reason it took me so long was because I stopped to chat to that policeman who kindly opened my water bottle for me; I stopped to chat to the lovely lady who was handing out HobNobs and I stopped at the Alzheimer's Society bus at mile six (my chosen charity) to have my picture taken. But even still, that only accounts for 10 minutes max. The harsh reality is the reason I was overtaken by a banana, a bloke in a mankini and a truly inspirational guy with a prosthetic leg was because I simply hadn't put the training in.

This brings me to why I am writing this blog. The reasons are as follows - if there is a written account, it might actually give me the motivation (kick up the backside) I need to train properly; I also hope to prove that if I can do a marathon than anyone can; and, lastly, if I was to keel over and die at mile 25, there will at least be a lasting piece of me somewhere on the internet superhighway (what was that I was saying earlier about no morbid feelings?!)

Don't misunderstand me; I'm under no illusions. This will be tremendously hard work. I don't expect for a minute that just because I train for the next four months that I'm going to whiz around the route and hardly break into a sweat or run out of breath. I know there will be tears, possibly tantrums, arguably blood, blisters, burning joints and that's just to start with. And I aim to give an honest account of any triumphs, however small they may be, as well as the hurdles I experience along the way. It won't be easy, but if it was it wouldn't be a challenge, would it?

Nor am I expecting to complete the course in a record time. Realistically, if I can walk/jog a half marathon in under three hours, I'm looking at somewhere between six and seven hours for the full 26.2 miles. (I sense more sniggering). But what does that matter? Katie Price took seven hours and 11 minutes (yes, I know she had hurt her knee, and she has two other things that will slow her down more than me, but I thought it was still worth pointing out). The fact is, the people finishing in a quicker time won't get a bigger or shinier medal than me and their souvenir T- shirt won't have been handwoven by fairies. I've always believed in the saying "it's not about winning, it's about taking part", mainly because I've always been useless at sports and it makes me feel better, but it's true.

So, with the date of the Virgin London Marathon - April 22 - circled and underlined on my calendar - it's on with the plan. It's time to dig out my trainers, which have been in their box since the Great North Run, and go for a jog. Oh, hang on, is that a rain cloud overhead? And it is pretty windy today, that'll only slow me down. Maybe I should stay in and do a workout DVD, or go on my exercise bike instead. I'll go for a run tomorrow - promise.