Really agree with these two points from Peter:

"In conclusion, only running Marathons can teach you how to pace  for a marathon"
"If you start slower and do the second half quicker your self esteem will be boosted, the other way round you will wonder what went wrong"

Sums up my thoughts and experience very neatly!

Hi Graham. This passage was given to me by another reader of THE RUNNERS WORLD MAGAZINE. Its an extract from a book, I forget the name of the book but it really help me last year.

“When you stand on the Start Line, you join the club. When you stand at the Starting Line you earn your membership. Millions dream of being where you are. You are no longer a dreamer. You are a doer.

Thousands more started a training programme but never finished. They started with the same enthusiasm as (or more than) you. They started with more or less the same physical gifts or disadvantages as you did. They had no more and no less reason to be successful than you.

But somewhere along the way, they lost that enthusiasm. Somewhere on the road or on the track or treadmill, they decided that the rewards just weren't worth the effort. They decided that they could live without finding their limits, without challenging their expectations of themselves and without taking a hard look at their image of themselves.

You didn't. If you’re standing at the Start Line, you've not only accepted the challenge, but you've also beaten back the demons. You've conquered your imagination and self-imposed limitations. You've gone further, got stronger and become tougher than you ever imagined."

Hi Graham. I am a similar pace runner to yourself. I ran my first Marathon in London Last Year. I am currently doing my taper for the Paris Marathon on 10 April. I speak only from my experience and there are many others out there with many more marathons under their belt. i did 3 x 20 mile runs last year at around 10 mins/mile pace. They all went well so that was my plan for the VLM. At 24 miles I was exactly on pace then as I  passed under and underpass ( Blackfiars area) lots of fellow competitors took the opportunity to use the underpass walls to stretch their leg muscles. I thought I was ok but the sight of so many people stopping blew a fuse in my head and I began to walk. 30 metres later I began to run again but nothing like I was running my final 2 miles took me 33 minutes. ( That pace is ridiculos)  In conclusion, only running Marathons can teach you how to pace  for a marathon, and as a real generalisation LESS IS BEST. Most elite runners do negative splits i.e. 2nd half quicker than the first half. If you start slower and do the second half quicker your self esteem will be boosted, the other way round as in my case last year you will wonder what went wrong. Please post a message after how you got on. GOOD LUCK. You will remember the day forever.

Hi Graham,

Firstly congrats on the great result in the half. That's something to really be proud of.

A couple of years ago, I was in a very similar position to you now. I was gearing up for my first marathon (also London), my training was going well, I'd got confidence in a couple of halves - similar time to yours. I saw 4.30 as my main goal, but deep down I wanted 4 hours. In the end I finished with 4.12, and there were a couple of things I really learnt which I think stand me in much better stead now.

1 - I didn't have a nutrition/hydration plan. I grabbed water or energy drink occasionally when I remembered. But I hadn't thought it through properly or practiced and that's probably the biggest thing I've learnt. Have a sip of drink every couple of miles, take an energy gel every 5 miles or so.

2 - I wasn't mentally or physically prepared for 26 miles. I'd done 20 in training a few times, and thought that it's more or less the same thing. It really isn't! Those last 6 miles are like a whole new race - I entered the unknown. I was on course for 4 hours at 20 miles but I gained nearly 2 minutes per mile in the last 6 miles. My body and brain started behaving in unfamiliar ways and I wasn't prepared for that - in hindsight, that was "The Wall"!

My advice is that you should start slow (say 9.45m/m), and gradually pick up speed if it feels right.  Really get in tune with how you're feeling around 16 - 18. If you feel strong, pick it up very gradually! You honestly don't want to get to 20 and find you're out of energy because those last 6 miles will seem like forever.

I've found the predictor calculators a little bit misleading to be honest. The step from half to full marathon really is a whopping big one! I wouldn't want to discourage you from going for it, but to be really honest I'd advocate a bird in the hand rather than two in the bush!

Whatever happens, make sure you remember to enjoy it. I look back on it as genuinely one of the best days of my life, and I'm sure you will too. You've already made incredible progress to get this far, and I'm sure you'll learn from the experience, and it'll leave you hungry to do it again. Good luck!!