BEIJING - Tyler Christopher lumbered down the homestretch Monday as if he had weights attached to feet.

In a way, perhaps he did.

The 24-year-old from Chilliwack, B.C., carried Canada's hopes of a track medal into the Bird's Nest stadium in Beijing. But his dreams were dashed in stunning fashion when he failed to advance out of the heats in his slowest run of the season.

"Disappointed? That's a bit of an understatement," Christopher said as he leaned over a barrier, looking down at the ground through his dark performance shades. "Disappointment would be not making it to the final.

"Not making it out of the heats, that's just ridiculous."

Christopher didn't appear to be himself during his 400-metre heat, and revealed afterwards that he picked up a flu bug at the team's training camp in Singapore.

He feels that may have played a role in the early end to his Games.

"I couldn't really get out of my bed until two days ago. It was just a lack of energy, my body was just completely fatigued, it hurt to touch, it hurt to lay down, it hurt to do everything," Christopher said. "I thought I was over it, but it seems like it still has taken a lot out of my body."

The six-foot-one runner looked sluggish out of the blocks and failed to make up any ground on the field on his way to a fifth-place finish in 45.67 seconds, the identical time he ran in winning the world indoor championships in March in Valencia, Spain.

"It basically felt like half my speed was missing," said Christopher. "I got to one slow constant speed, couldn't pick it up from there."

Christopher arrived in Beijing ranked sixth in the world, and just a few months removed from his gold-medal performance in Spain. He was touted as one of Canada's top hopes for a track medal, and the New York Times went as far as to name him a potential "surprise winner."

But high expectations can do funny things, said Christopher's coach Kevin Tyler.

"There's a physical and mental component to performing, and I think the flu was just another response to his immune system that has been down because of the pressure," Tyler said. "It's been displaying itself in various mechanisms ... problems with his breathing, heavy legs, illness."

Christopher opened his season with a promising 44.71 in California, and was confident his Canadian record of 44.44 set in winning bronze at the 2005 world championships would fall. But he's failed to break 45.0 since, and struggled with breathing problems at the Prefontaine Track Classic in Eugene, Ore., in June.

The Canadian track and field team set its sights on two medals in Beijing, but it was a goal set before hurdler Perdita Felicien bowed out with a stress fracture.

With the former world hurdles champion gone, the glare of the spotlight turned directly on Christopher, along with 800-metre runner Gary Reed.

Tyler believed Christopher could handle the pressure, that he's usually at his best in big races.

"But this is his first Olympics and this is how he responded to it," Tyler said. "He's never responded like this. Now it's going to be about taking some time away, think about what's important and see how he'll respond to this. A lot of top athletes have bottomed out before they've made it to the top, and maybe this is what he needs to happen.

"Right now he's sad, he's concerned that he's let us down, but I don't feel that way at all."

The crushing exit was yet more Olympic disappointment for the wiry sprinter, who narrowly missed qualifying for the 2004 Athens Games, running the time he needed to make the team two weeks too late.

"Whatever, (stuff) happens," Christopher said, as he tried to catch his breath after the race. "I'll get over it and assess what I want to do and get on with the next race. There's a lot of good people that aren't going to make the finals, or don't get out of the heats, it happens to a select few, it just happens this year that I'm one of them."

Andrew Steele of Great Britain won Christopher's heat in 44.94, while Chris Brown of the Bahamas ran 44.79 for the fastest time on the morning.

World and defending champion Jeremy Wariner cruised to a time of 45.23 to easily go through to Tuesday's semifinal, while fellow American LaShawn Merritt also advanced.