They have logged thousands of hours training in gyms, on fields and on the ice, transforming their bodies into finely tuned machines fit to conquer the greatest of sports competitions.

But in the final lead-up to the Games, they also practice stealthy evasion of the invisible microbes that threaten to cripple performances with fevers, runny noses or, worse, a full-blown flu.

What's in their arsenal of prevention?

Flu shots, surgical masks, Cold-FX, supplements, hand sanitizers - even sleeping pills. There are also power naps and, most importantly, efforts not to get too stressed about the possibility of falling ill.

"All I can do is just try to be healthy and eat well, and if I get sick, that's just going to really suck," says Canadian snowboarder Michael Lambert. "But being paranoid about it isn't going to help me."

By no means a germophobe, Mr. Lambert still takes Cold-FX to keep himself healthy. Travel, after all, goes hand in hand with a host of viruses. He remains vigilant about his diet on the road, and takes sleeping pills in the first few nights when he flies to Europe or Asia to make sure he gets proper rest.

But when he's home, "I don't schedule anything before 12," he says, which allows his body to wake up when it wants to. "With the amount of abuse we go through on the road, I think it's so important to take the time when we're at home to do everything we can to get healthy again. That's the way I see my time off at home."

Kelly Anne Erdman, lead dietitian for the Canadian Sport Centre in Calgary and a nutritional consultant for Olympic-bound athletes, says her role is to educate them on healthy living habits, especially in the run-up to a world-stage event where their stress level climbs by the day. Sports psychologists work with athletes to manage the pressure, and nutritionists remind them to keep their diets consistent.

"When the athletes are performing, their bodies are obviously under stress. There's the psychological stress plus they are bombarded with all the germs that have come in from all over the world," Ms. Erdman says. "It's a constant for athletes: How can they stay healthy?"

For Canada's short-track speed-skating squad, one of the ways to keep the flu bug at bay is wearing masks in airports and on planes.

Yves Hamelin, the team leader, says the team revisited its procedures after a 2007 World Cup trip to Asia where 14 of the 17 people on hand picked up a stomach bug - "everyone was sick, and not just a little bit."

The athletes have been inoculated against H1N1 and seasonal flu. The upshot is that no one on the short-track team has caught the flu yet this year, although a handful have had colds.

Because the skaters' diets are carefully mapped out as part of their training regimen, the team also brings nuts, oatmeal, dried fruits and granola bars on the road. On longer trips it totes peanut butter, jam and hazelnut spread.

"When we travel, we usually bring a pantry full of food along to make sure there's no difference with their usual dietary habits," Mr. Hamelin says. "We wash doorknobs, sinks, faucets, the television remote. We wash it all with Purell or a disinfectant. That's where contamination occurs most often. ... In the airport and on the plane they wear masks so they're protected."

The women's hockey team hasn't gone to such drastic measures. Sure, there are those like defenceman Becky Kellar, 35, who carry hand sanitizer in their knapsacks. But the team's strength and conditioning coach, Ryan van Asten, says it's impossible to keep germs out. In the meantime, the team maintains its healthy living strategies - promoting eating every two to three hours and getting plenty of rest - in the weeks before the Games, hoping no one gets ill.

"We try to educate them as much as possible," Mr. van Asten says. "If their nutrition is lacking, their risk of getting sick is going to go up. If they're not sleeping, their risk of getting sick is going up. All throughout the year, we try to educate them on how to minimize their risk of getting sick and being as healthy as they can, so that they can perform at their best at the right time."

Staying healthy is all well and good. But athletes, like the rest of us, have their cheats. For Mr. Lambert, it's a particular brand of chocolate ice-cream.

"I try to make the best choices that I can most of the time," the snowboarder says. And the ice-cream? "That keeps me happy. For my mental wellness, it's Haagen-Dazs."