London Marathon: Scott Overall plots London 2012 campaign

When Scott Overall lines up alongside the world's best marathon runners on the London 2012 startline it will only be the second time he has raced 26.2 miles.

Indeed, a year ago the Londoner talked, rather than ran, marathons.

The 29-year-old used to advise weekend plodders and joggers as part of his job in a running shop in south London.

That came to an end in September when he ran two hours 10 minutes and 55 seconds on his marathon debut in Berlin to become the first, and so far only, man selected for Great Britain's athletics team for the London Games.

This week Overall has been dispensing advice to amateurs again as he prepares for the London Marathon on Sunday.

Unlike them though he is not concerned about completing the course, knowing that his pace-making duties will be done and dusted around the 18-mile mark.

"I am going to run the London Marathon one year so it enables me to learn the course and get to know the procedures without actually having to race it," he told BBC Sport.

"This year gives me a chance to practise the drinks. The only time I have run and taken on board fluid was at Berlin's marathon.

"And if I can help some of the other British guys do the qualifying time then that will be good as well."

To run the full distance only once before the Olympics may seem a relaxed approach, but the marathon is not a casual event and Overall is not a casual athlete.

His initial aim was to represent Great Britain on the track, as he did at the 2005 under-23 European Championships and 2010 World Indoors.

However, London Marathon race director Dave Bedford persuaded him to try the longer discipline and was proved right as Overall won his place at London 2012 with more than seven months to go.

"Obviously you can't run marathons repeatedly," explains Overall.

"A lot of the the British guys are doing a marathon now around the end of April to qualify because they have not yet run the qualifying time.

"If you do that, you are squeezing everything in because you will take a few weeks off to recover and then you would ramp straight back up for the Olympics.

"Being selected early has allowed me more time to focus on training rather than chasing qualifying times."

It is a luxury that has not been afforded to some of the favourites.

Geoffrey Mutai won last year's Boston and New York marathons, clocking the fastest time ever en route.

But such is the competition for places in the Kenyan team, he ran the Boston race again at the weekend, dropping out as temperatures rose above 30C.

Overall is confident that he does not have to get involved in another big-city race before the Games.

"I have got a lot of experience on track and in road races. The only thing different is the distance and if my training all goes to plan I will be prepared for that," he said.

"The Olympics will be very different from a big-city marathon where it is all about time. The Olympics is a championship race. No-one is concerned about how quick they run, just where they finish.

"You look at the history of Olympic marathons and they are usually won in around 2:08 or 2:07.

"I think I am capable of getting in that sort of shape and on the day it is a case of making sure I cover the moves made by Kenyans."

Of the top 20 marathon times clocked by British men only two have come in the last decade, and Overall concedes the event is not seen as "overly glamorous" by the rest of the athletics team.

They may have a point with the marathon denied a finish in the Olympic Stadium by a city-centre route.

But if Overall gets it right on 12 August the excitement is unlikely to be diluted by the fact it is taking place on tarmac rather than track.