Colin Jackson: Hard lessons learnt in the human laboratory

Yesterday's Olympics treated us to the two extremes of athletics, the endurance race which tests the body to its limits, and the heavyweight showdown, the sprint, which is in the mind.

Yesterday's Olympics treated us to the two extremes of athletics, the endurance race which tests the body to its limits, and the heavyweight showdown, the sprint, which is in the mind.

The worst moment for sprinters is 45 minutes beforehand, when you say goodbye to your coach and you're suddenly alone. In the call room, all your rivals are there, nobody acknowledging each other - except for Americans, who are always whooping and hollering. Maurice Greene, I can guarantee, will have been making noise last night, trying to intimidate Asafa Powell, the Jamaican who was favourite to win. Asafa's 21 and he'd never faced this pressure before.

Modern athletics is a strange beast: these men are professionals who have more than reputation or sporting pride at stake. The winner earns global fame and millions in sponsorship. An also-ran could struggle financially.

On the track, it hits you - the world is watching. Your rivals can play all sorts of tricks. Many times I found my blocks moved or spit in my lane where I would place my hands. Doubt crowds your mind: what on earth are you doing there? The race is like a human laboratory, testing each man. You take a deep breath, assert control, and concentrate. Experience counts for a lot.

From the minute Asafa came out you could see he was anxious. He couldn't relax. And here is how unforgiving the Olympics are: the gun goes, four men run under 9.9 seconds and next thing you know, Justin Gatlin is running around the track wrapped in his country's flag. Asafa is left wondering what happened.

For Paula Radcliffe, none of those factors applied. She is a great athlete and prepared phenomenally well. But yesterday was very hot and some of the other runners were better suited to it. Mizuki Noguchi, who won gold, is from Japan, where the climate is comparable in the summer. Catherine Ndereba, who was second, is Kenyan. Paula gave it everything but she's from dear, rainy old England. You can train, but you can never change where you've come from.