For Paula Radcliffe, it prom-ises to be a marathon day - more so than usual. Two years ago her work was done in 2hr 18min 56sec in the Flora London Marathon. Last year it was over in world- record time, 2hr 15min 25sec.
Today, as the notable absen-tee from the 33,000 field, the leading lady of long-distance running has the form of her Olympic rivals to assess, and the progress of her younger brother, Martin - a marathon debutant at the age of 28 - to follow. Then there is her two-hour Sunday training run to fit in. She will not be standing admiring the opposition when the gun fires to start the Olympic marathon on 22 August.
"I've not decided what to do yet," Radcliffe said, assessing her London race-day options. "I'm just trying to work out when to do my own run - whether to run and then watch the race or watch the race and then do my run." At least, whenever she gets around to her own high-speed spin (120 minutes at something less than six-minute mile pace), the pride of Bedford and County Athletics Club will be treading her path secure in the knowledge that she is firmly back on track for her golden Olympic shot.
At a gathering of British athletics writers in Victoria on Friday, Radcliffe revealed that she had undergone surgery on 24 March to remove a hernia from her groin. She also disclosed that tests had confirmed she was suffering from a viral infection when she last raced, in the World's Best 10km Road Race on 29 February.
It was clear that Radcliffe was not at her best in Puerto Rico - she was beaten by Lornah Kiplagat, her first defeat in an individual event for 17 months - and yet, at the time, her run was seen by some as a shift from invincibility to vulnerability. In retrospect, her performance has assumed a wholly different meaning.
Instead of leaving a psychological scar on a woman who was hitherto blazing an untouchable trail, it has become a source of renewed confidence. Despite the stormy conditions in which the race was run, despite the viral infection, and despite the presence of the hernia that was discovered after her withdrawal from the World Cross Country Championships last month, Radcliffe still managed to clock 30min 45sec, just 24 seconds slower than the world-record time she had set on the same course 12 months previously.
"Psychologically, it is encouraging to think I could still run a time like that," she acknowledged. "It's also encouraging to think that my training was going so well." It is going well now, too - three-and-a-half weeks on from the surgery Radcliffe underwent in a Munich clinic.
"Having the operation when I did was a blessing in disguise," she maintained. "If I hadn't had it done, it would have caused problems further down the line, possibly for Athens. It was responsible for the hamstring injury that made me miss the World Cross Country Championships and it would have grumbled on, because it was causing weaknesses in my hips and legs.
"As it is, I'm back in full training and those areas are strong again. I've only missed a little bit of training and one race. In terms of Athens, that's not a problem when it happens in March and April."
There are still 18 weeks to go before Radcliffe's Olympic destiny will be decided on the road from Marathon to Athens. She plans to resume her racing schedule next month - after getting through her marathon schedule on London Marathon day.