Respect the distance
Double Olympic champion Mo Farah steps into the unknown on Sunday when he makes his marathon debut in London
Like many of the 30,000 who will toe the line at the London Marathon on Sunday, Mo Farah will do so with a certain amount of trepidation, vowing to follow the amateur's mantra of "respect the distance, be patient and see where it takes me".
Farah's ultimate target, however, is some way removed from the rest of the field as, in his first crack at the revered 42.2-kilometre distance, he is planning to take on and beat one of the best elite fields ever assembled.
Four of the 10 fastest men ever - seven of the top 20 - including two hours, three minutes and 23 seconds world record holder and 2012 London winner Wilson Kipsang, will race at a pace that Farah hopes, but is not yet certain, he can live with.
When I'm training normally I know I can do reps of 5km or whatever it is but for the marathon it's so much harder as you just don't run those distances very often
"It's completely different, track to road," the world and Olympic 5,000 and 10,000 metres champion told a news conference held in the shadow of Tower Bridge, the iconic halfway mark of the race. "When I'm training normally I know I can do reps of 5km or whatever it is but for the marathon it's so much harder as you just don't run those distances very often.
"But I've learned a lot and am really looking forward to it. Now is the time to test myself and find out if I'm good at it or not."
"Good", of course, is a relative term for a man with a sound claim to be Britain's greatest-ever athlete. Such is the progress he has made over the past four years, with his superlative distance double among the highlights of the London Olympics, that expectation levels among the public have rocketed.