It’s not hard to spot a first-time marathon runner. If the Lycra, antisocial running times, colour-coded training plan, running watch and constant look of fear don’t give it away, then the plates of pasta and stack of gels certainly will.

However, what no one tells you when you sign up for a marathon – which is, let’s face it, a very long way – is that the word “marathon” isn’t just a description of the 26.2-mile endurance race you are going to run. In truth, the marathon journey is a lot longer than that (and I’m only six weeks in to training). It also involves a lot more than just running.

When you’re not clocking not up the miles, you’re thinking about them, talking about them, even dreaming about them. Days are no longer measured in hours but in miles completed and laundry baskets filled.

For someone with a cancer-scarred body and a hip full of metal (from having my pelvis sawn in three and repositioned eight years ago), the starting line of the London Marathon means everything to me. I started thinking about it when I ran my first ever 10k during chemo. I started dreaming about it as I hobbled my way injured around my first half marathon last year. Now, six weeks in to my training plan, I am starting to think that this rearranged body of mine might just make it.

People talk a lot about those 26.2 miles, but they talk a lot less about the miles you have to run - and the hurdles you have to overcome - just to get there. Here are a few of the things I just wish I’d known before I hit the road.

1) The first step is always the hardest

Excuses, excuses, excuses: you wouldn’t be a marathon runner if you weren’t full of them. We think nothing of signing up for a hardcore endurance race, only to be put off training by a drop of rain. My favourite excuse so far? I would have run home if I’d had a bag for my phone and iPad. But the truth is, apart from a rather painful encounter with a treadmill, I’ve never regretted going for a run – or the feeling that comes with it. I have, however, regretted turning over in bed. Tomorrow isn’t always a better day; it’s just one day closer to race day.

2) Your life won’t be complete without a weather app (or three)

Don’t believe me? Then get downloading and see if you can tear yourself away from those fluffy white clouds. Just remember: no amount of refreshing will change the picture, and a race in the rain can actually be fun, so long as you have taken the necessary precautions and found a bag for that phone (see 1). Just don’t expect your weather apps to always agree.

3) Your days will suddenly seem a lot more dangerous

You can survive for decades without even thinking about the cobbled streets or the kerbs in your life. But start marathon training and I guarantee that you’ll think about nothing else. Who knew that life could be so hazardous? Even a trip to the bathroom takes on a new meaning when there are stairs involved.

4) Your chat should come with a health warning attached

I’m sorry, but there’s a reason those party invites have dried up and it’s got nothing to do with your gruelling training schedule. Truth is, unless you’re talking to runners, running chat really isn’t that exciting. Talk about how far you’ve come and you’ll probably just be encouraged to get a move on, preferably in the opposite direction. I love nothing more than learning a new running term but now understand that this isn’t a view shared by friends, family and colleagues.

5) You’re not the first person to take on a marathon and you won’t be the last, so ask the experts.

If you’re running London this year, you’re set to be #oneinamillion. That’s a lot of runners and a lot of good tips. How was my life ever truly complete without a foam roller? Every running wardrobe really does need a second pair of trainers (in case the first pair fails close to race day). And, I will be for ever grateful to the nutritionist who told me that you can go a long way on one banana.

6) ... just make sure that they really are experts

When you’re taking on a challenge of marathon proportions, it seems everyone has a view, whether that’s the ultramarathoner who tells you “it’s not that far” or the couch potato who advises on the placement of Vaseline. What you choose to do with your nipples is your business.

7) It’s OK if things don’t go according to the plan

Now is the time to listen to your body, not the highlighter pen on the training plan. Yes, we all want to stick with the programme. But, I’ve been told on more than one occasion that there is enough fat in the plan to allow for a few injury breaks. I listen when my metal-filled left hip protests.

8) There are no bad runs – just great stories for down the pub

This great piece of advice was given to me by serial marathon runner Laura Fountain. As point 4 suggests, no one wants to hear when you’re clocking up those milestone and not tripping on kerbs. But throw in a few tales of woe and you might find yourself with an audience. People switch off when I talk about my favourite ever run at the Royal Parks half marathon last year, but they can’t get enough of my “hornet stung my bum cheek” running tale.

9) Mind those carbs

Sadly, there is a reason why many people training for a marathon don’t lose weight. I think it might have something to do with the fact you only ever run 26.2 miles once but there’s a temptation to eat like you’re doing one every other day.

10) Believe you can and you’re halfway there

When I tell people I’ve got a hip full of metal, most start talking about whether or not I should be running a marathon, not whether or not I can. In truth, I still don’t know whether I will make the starting line. What I do know, however, is that a little bit of self belief and determination can take you a long way. And, by taking every step for the amazing charity Breast Cancer Care - who supported me when I was undergoing treatment in 2014 - I know I will do everything I can to go the distance.