LONDON It is hard to believe a race that lasts barely 10 seconds can seriously mess up your mind but when it is the Olympic 100 metres final, there is little doubt it can.
Intrusive thoughts about failure and humiliation can plague sprinters for months before a race. The constant stress then starts to interfere with hormones in the brain, making sleep, concentration and training suffer.
As Jamaicans Asafa Powell and Usain Bolt know well, one false start can wreck hopes before a race has even begun and haunt the psyche for years.
While endless honing of fitness and form is crucial for the world's fastest human beings, it may be brain training that makes the difference between glory and defeat.
"By the time they reach this level, elite athletes are fit, they're fast, they've done their homework, they know who they're up against. So it's hardly ever a skills issue," said Pieter Kruger, a London-based sports psychologist who has worked with many elite athletes including the 2012 British Olympic team.
"At this point it becomes about the application of skills under pressure - that's where the psychology comes in."
On the face of it, the men most likely to be lining up for the 100 final on Sunday August 5 seem very different.
Sprint king Bolt, a laid back, light-hearted showman, is rarely lacking in confidence and appears far more relaxed than compatriot Powell - a known worrier who has struggled to get over pre-race nerves in the past.
America's fastest man Tyson Gay is softly spoken and humble, keen to avoid bold predictions and pre-race posturing.
He has found the psychological aspects of training, especially when coming back after an injury, particularly tough.
"When you're a little bit banged up it plays on you mentally a lot because you realise you only need to be 100 percent, feeling good, for one race - and that's the final," he said.
Powell knows he must ignore his rivals and focus on his own performance.
"I should just stay composed and run to the finish line," he told Reuters earlier this year. "You don't want any doubts in your head."
CONTROL THE CONTROLLABLES
Sports psychologists agree that is exactly the right approach but is far easier said than done.
"One of the worst things athletes have to deal with is something called anticipatory anxiety," explained Kruger.
"These are very intrusive thoughts. They start in the weeks leading up to a big race and they're often very much focused on outcome goals - in other words 'I need to win, I've spent four years training for this, I don't want to fail'."
If athletes cannot get a grip on these fears, they build to a point that produces a state of almost continual stress, triggering a constant secretion of the stress hormones cortisol and adrenaline in the body.
"That can really interfere with sleep patterns, recovery, training, rest - and when we're talking about milliseconds of difference between a first and a fifth place, all these things become incredibly important," said Kruger.
What team psychologists and coaches need to do is help athletes redirect those thoughts towards the process rather than the outcome, so their minds are focused on how to run their best race, not on obsessing about whether or not they can win.
"It's about controlling the controllables," said Kruger. "You can't control the outcome but you can control everything else in the process."
In a list of the top 10 questions an athlete must be able to answer correctly, American 400 metres great Michael Johnson said a crucial one is "What really matters right now?"
The answer? "The only thing that matters is the race you are about to run. The focus required to compete at this level and under this pressure requires an athlete to be totally in the moment".
Damon Burton and Thomas Raedeke, authors of "Sports Psychology for Coaches" suggest sprinters should have a clear race plan, possibly with cue words for each phase, and should mentally rehearse their race until it becomes second nature.
"Thinking too much is the worst possible thing they can do psychologically," said Burton, a professor of sport psychology at University of Idaho in the United States.
"You want sprinters in that situation to keep their minds clear, stick to a routine, react to the gun, and just do what they can do as best as they possibly can," he said in a telephone interview.
"The worst thing is if they start having nagging self doubts in the back of their minds."
So far at least, Bolt seems to have got that message.
"I have no worries," he told Reuters on Thursday. "It is not over-confidence. I know what I can do."
(Editing by Justin Palmer)