One of the teams leading the way in capitalizing on that advantage is the Seattle Seahawks, who won the Super Bowl in 2013 and came within two yards of repeating their victory in 2014. Head coach Pete Carroll is known as much for his innovation off the field as on it. “When it comes to the precision and science of sleep for optimal performance,” Carroll told me, “we’ve been fortunate to work with experts to help guide us on both the physical and mental strategies to enhance our recovery process.”

Two of the experts leading his science team are Sam Ramsden, the team’s director of player health and performance, and Michael Gervais, the director of high — performance psychology at the DISC Sports & Spine Center. Together, they educate both players and coaches on the importance of sleep. “Fatigue and performance are intimately linked,” they told me, “and sleep is one of the important variables to get right to help athletes sustain high effort and enthusiasm for the long haul.”

This isn’t news to the New England Patriots’ quarterback Tom Brady, who managed to beat the Seahawks in the last Super Bowl — -and win the MVP title. Brady goes to bed at 8:30 p.m. and is still managing to play at the highest level even as he approaches forty. “The decisions that I make always center around performance enhancement,” he says. “I want to be the best I can be every day.”

The Chicago Bears are employing a similar strategy. Their sport-science coordinator, Jennifer Gibson, teaches players how to develop good sleep habits and proper napping techniques as a way to maximize performance, and provides them with memory-foam mattresses during training camp. Pro Bowl guard Kyle Long has become an enthusiastic sleep advocate. “Getting that eight, nine hours is just as important as weightlifting and studying your playbook,” he says. “I can know all the plays like the back of my hand. I can lift all the weights in the world. But if I get five, six hours of sleep, I’m going to have that doubt in my head and that sluggish nature, and you can’t have that when you’re trying to block these elite guys. I’d absolutely say sleep is a weapon.”

As former NBA All — Star Grant Hill put it, “People talk about diet and exercise,” but “sleep is just as important.” Four — time NBA MVP LeBron James swears by twelve hours a day when practicing. And two — time NBA MVP Steve Nash believes that “napping every game day, whether you feel like it or not, not only has a positive effect on your performance that night but also a cumulative effect on your body throughout the season.” Professional triathlete Jarrod Shoemaker describes sleep as “half my training,” while Usain Bolt, the world’s fastest man, explains, “Sleep is extremely important to me — -I need to rest and recover in order for the training I do to be absorbed by my body.” Volleyball player Kerri Walsh Jennings, a three — time Olympic gold-medal winner, admits that sleep “could be the hardest thing to accomplish on my to — do list, but it always makes a difference.” And tennis great Roger Federer trumps them all. “If I don’t sleep eleven to twelve hours a day, it’s not right,” he says. “If I don’t have that amount of sleep, I hurt myself.” Before Wimbledon in 2015, he even rented two houses: one for his family to sleep in and one for him (and his training team), so the family activities wouldn’t wake him.

This recognition of sleep’s impact on performance is now a worldwide phenomenon. In the United Kingdom, the Southampton soccer club has its own sleep app, which players use each morning to log the previous night’s sleep. If a player’s sleep-quality level drops, team officials will intervene. The Manchester City soccer club has a new £200 million training center that includes eighty bedrooms. The team sleeps in the training center the night before home matches — -a recognition by the coaching staff that sleep isn’t just for training but an integral part of game — day -preparation.

Nick Littlehales, a sleep coach for Manchester United as well as other top soccer clubs, rugby teams, and the UK cycling team, will often go to a venue ahead of the players to make changes to their hotel rooms. “I have been preparing with various teams for the 2016 Rio games,” he told me, “and a key part of that is ensuring the hotels being used in the run-up to the games are ticking all of our recovery boxes.”

At the college level, making the sleep/performance link is even more important, since the athletes are younger and even more likely to be in the “I’ll sleep when I’m dead” phase of life. A 2015 Wall Street Journal headline read, “College Football Wakes Up to a New Statistic: Sleep.” Pat Fitzgerald, the head football coach for Northwestern University, noticed in 2012 that many of his players seemed especially tired during afternoon games. It turns out the reason was that the games occurred right when his players were used to taking afternoon naps. So he started a policy of mandatory game — day naps. That year the team won ten games, for only the third time in the history of Northwestern football. “At first, we didn’t really know much about sleep and we were just curious,” then–-defensive end Tyler Scott said. “But we really embraced it, and after a while, we got really competitive about sleep efficiency. We started checking our data every day.”

Other teams are taking note. At their 2015 training camp, University of Tennessee football coach Butch Jones introduced his team to a new part of their practice routine — -sleep trackers and sleep coaches. The team worked with Rise Science, which helps athletes improve performance through sleep. They paired each athlete with a sleep coach and monitored everything — -from the amount of time players sleep to how long it takes them to fall asleep to the quality of their sleep — -with the results sent directly to a smartphone app. The players also wear orange — tinted glasses an hour before they go to bed to help eliminate the blue light from screens that can disrupt sleep. “It was very powerful to see the cultural shift at the University,” said cofounder Leon Sasson. “It went from who can sleep less and still do well at practice to it being cool if you show up to practices with nine — plus hours of sleep under your belts.”

At the University of Pittsburgh, coach Pat Narduzzi makes sure his players get enough sleep by coming into their dorms and tucking them in at night himself! “We’ve got lights out at 10:30 and bed check at 10:45 every night, so we’re trying to get them down early. . . . We can’t close their eyes at night for them, but you can see it on the field that I think our kids are getting better rest.”

Excerpted from THE SLEEP REVOLUTION by Arianna Huffington. Copyright © 2016 by Christabella, LLC. Published by Harmony Books, an imprint of Penguin Random House LLC.

Originally published at journal.thriveglobal.com