By now, we know that sleep is as important as diet and fitness when it comes to sports performance -- too little shuteye can affect concentration, recovery time and athletic longevity, to name a few.

But it looks like some of our favorite athletes may have come down with a case of Olympics-induced insomnia.

"After we won [the team all-around gold medal], we celebrated with our families in London and I haven't been able to sleep since because of all the excitement!" American gymnast Jordyn Wieber wrote in a blog for People.com.

U.S. track and field star Sanya Richards-Ross echoed the sentiment -- the night after winning a gold medal for the 400 meters, she said she only got four or five hours of sleep before returning to the track for another day of semifinals, according to ESPN.com. "[My family] kind of celebrated until about 2 this morning. Everybody kept saying, 'Go to sleep, go to sleep, you have to run tomorrow,'" she told ESPN. "Even when I laid down I couldn't sleep. I was just so excited." (She ultimately placed fifth in the 200 meter final a few days later.)

And swimmer Dara Torres told Health magazine earlier this year that she sometimes turns to medicine to help her conk out the night before the race. "There are a lot of athletes who will take it if they need to fall asleep before they compete -- because you're thinking about your race and you're tossing and turning," she told the magazine. "I'll take an Ambien if I'm having a really hard time going to sleep."

So what, exactly, makes it so hard to sleep in the Olympic village? It's likely a variety of factors, experts told The Huffington Post, including jet lag, a changed environment, nerves and all that excitement (The Duchess! Tweets from Justin Bieber! LeBron!).

"Nothing in our body is random," says W. Christopher Winter, M.D., medical director of the Martha Jefferson Hospital Sleep Medicine Center in Charlottesville, Va., who is working with several athletes competing in London right now. And because the games are only every four years, it can be difficult to know exactly what to expect. "You can't be particularly seasoned in the Olympics," he adds. (OK, unless you're Michael Phelps.)

And that means that the out-of-towners who can't afford to spend weeks re-acclimating to London time could find themselves at a disadvantage, fighting against their circadian clocks by eating, training and, yes, sleeping against their natural schedules.

On top of that, as anyone who has tossed and turned in a hotel bed can attest, sleep can be disrupted in a new, unfamiliar environment. We all naturally wake up several times throughout the night, Winter explains. In our own beds, we typically drift back to sleep without even noticing -- away from home, though, we might be disoriented for a few minutes, which can ultimately disrupt sleep. Plus, we all pick the mattresses, bed covers and sheets that make us feel comfortable at home, but that level of customization isn't usually available on the road. (It's no mystery, according to Winter, why the home team often sees a boost in medal count, as they don't need to make any of the same adjustments.)

Add all that to the immense pressure to sleep the night before competing, and you have a recipe for disaster.

"Sleep is like men having sex," jokes Joe Ojile, M.D., founder and CEO of the Clayton Sleep Institute in St. Louis, Missouri and a board member of the National Sleep Foundation. "If they know they have to do it, it becomes very difficult."

The phenomenon is hardly unique to the Olympics -- earlier this year, for instance, Knicks forward Steve Novak told a radio host that the team was having trouble sleeping in the wake of 'Linsanity.' "We have a lot of guys who have trouble sleeping at night," he said at the time. "I'm serious. It's like the energy when we leave -- it's like it's midnight, and you go home and we can't sleep."

And yet sleep is critically important to athletic success. "Nobody performs well when they're sleepy," Winter says. "It's almost like asking why is eating important with athletics."

The human growth hormone is secreted during deep sleep, he explains, which is essential for recovery (especially when you're brutally competing day after day). And Ojile adds that quality rest is key for both immune function and focus -- particularly crucial when hundredths and thousandths of a second are on the line.

"It doesn't take much of an advantage for a bronze medalist to become a gold medalist or someone off the podium to get a bronze," Winter says. "Sleep's kind of everything."

So what, exactly, is a sleepless athlete to do? Both experts agree that getting quality rest is a skill that can be learned. And part of that, Ojile says, comes down to the basic sleep hygiene: avoiding technology and bright lights in the bedroom, and winding down at night, whether that means meditating, reading a non-stimulating book or finding some other relaxing activity. "Their adrenaline is going to be so high, they have to overcome that," he explains.

Winter also recommends doing what you can to make your environment feel more familiar -- he tells patients, for instance, to spray lavender, which promotes sleep, on their pillows at home, even if they don't have any problems with insomnia. Then they can spray that same scent on their pillows while traveling as a sort of brain trick.

And he tells athletes to take the pressure off sleeping.

"Sleep is incredibly important and incredibly important to your health but a night of sleep is somewhat meaningless," Winter says. "I tell athletes all the time, I want you to care about your sleep a lot, but I want you to worry about it a lot less than you are right now."

And by not dramatizing it -- putting a few lost hours in the same category as, say, skipping a meal -- you might actually end up sleeping better. Tell yourself: "If it doesn't go well tonight, it's not that big a deal," he suggests.