I can relate to many among the 30,000 starters

But an ill-advised pub promise made just before Christmas meant I could not delay the challenge any longer.

Try as I might to backtrack, the appearance of the charity trump card left me stranded on the 26-mile road to hell.

Daisy's Dream, a Berkshire-based charity offering bereavement support to children, offered me my place among the 30,000 runners taking part in this year's event.

So, by the time my left knee started groaning like an ageing oak tree, too many promises had been made to pull out of the event.

In truth, the physiotherapy I underwent as a result of my irritating knee injury is about as close as I have ever come to life as a professional athlete.

It was a case of professional treatment on amateur legs.

Like Haile Gebrselassie and Paula Radcliffe, I will be lining up in Greenwich for the first time.

There the similarity ends.

Legs are guaranteed to feel spongey

But there are plenty among the 30,000 with whom I can relate to as 14 April draws closer.

Like the man whose train let him down on the morning of the race, forcing him to run 26.2 miles on a treadmill in order to collect his sponsorship money.

To help me avoid such disasters within my hapless reach, I issued a cry for help to Bruce Tulloh.

As a former international runner and one of Britain's most respected coaches, with marathon stars such as Richard Nerurkar among his pupils, there are few better placed to offer advice.

Following Bruce's build-up plan helped me start my training build-up with a relative degree of confidence.

Injury robbed me of that burgeoning bullishness, though Bruce's sensible approach to progressing while recovering means I am at least fairly certain of turning up on the day.

So, as my final preparations for my London debut gather pace, I find myself cramming facts more prolifically than carbohydrates.

The regular and impressive literature received by every runner is proof that the organisers have thought of everything ahead of the big day.

You can even use your number in place of a London Transport bus ticket for a ride back to the finish in case of injury.

Now there's a thought!