Posted Aug 6, 2011
San Francisco — In a sleep-deprived country, where most Americans struggle just to get eight hours of shut-eye a night, a Stanford researcher asked a rather outlandish question: What would happen if folks aimed for 10 hours of sleep?
The answer for a basketball player: a better free-throw shot.
That’s according to a study, published in this month’s edition of the journal Sleep, of 11 players from Stanford’s varsity basketball team. They tried to get at least 10 hours of sleep every night for five to seven weeks — or two to three hours more than they were used to.
The players didn’t quite make it to 10 hours, but they did add about 90 minutes of sleep time, and the results were noticeable.
Collectively, they took almost a full second off of their times in 282-foot sprints on a basketball court, and they improved the accuracy of both their free-throw and three-point shooting by 9 percent.
“What these findings suggest is that these athletes were operating at a sub-optimal level. They’d accumulated a sleep debt,” said Cheri Mah , a researcher at the Stanford Sleep Disorders Clinic and lead author of the study. “It’s not that they couldn’t function — they were doing fine — but that they might not have been at their full potential.”
The study was very small, and the results will need to be confirmed with a larger group of athletes, Mah said. But the fact that every one of the 11 players saw improvements is pretty strong evidence that extra sleep can elevate athletic performance.
Whether the results would apply to the general population — in better performance at work or more energy at the gym — is hard to say, sleep experts say. But it’s been well documented that sleep deprivation negatively effects people’s short-term memory and moods, so it stands to reason that more sleep could have positive effects.
“The issue of athletic performance probably doesn’t apply to everyone. But everyone probably underestimates the impact of sleep deprivation,” said Dr. David Claman , director of the University of California at San Francisco Sleep Disorders Center.
In the Stanford study, the athletes first recorded their normal sleep schedule for four weeks, and on average they reported close to eight hours of sleep on a typical night. They all said they were already in peak physical condition.
Next, the athletes spent five to seven weeks trying to get much more sleep than usual, and they estimated they got on average about 10 1/2 hours of sleep every night. Their athletic improvements, they told researchers, were startling.
Aside from the improved shooting and running, they performed better on reaction tests, were less fatigued throughout the day, and their overall mood picked up.
It’s worth noting that the players probably didn’t get as much sleep as they thought. All of them wore a device on their wrist that measured their sleep time by monitoring their movements.
According to the devices, the players averaged about 6 hours and 45 minutes of sleep during the first four weeks of the study, and 8 1/2 hours during the next five to seven weeks.
Sleep experts warned that it might not be a good idea for everyone to aim for 10 hours of sleep every night. Aside from the fact that it can be impractical — Americans seem to have a tough enough time getting just eight hours — there’s a “U-shaped curve” for sleep duration.
In other words, too much sleep can be just about as bad for overall health as too little, research has shown. That’s why most people should aim for seven to nine hours, said Dr. Anil Rama , medical director of the Sleep Medicine Laboratory at Kaiser San Jose.
Still, the Stanford study seems to demonstrate that athletes — elite or not — might seriously consider making sleep a part of their training programs, alongside nutrition or weight lifting, sleep experts said.
Scott Dunlap , an elite-level distance runner who is training for this month’s San Francisco Marathon, said he started incorporating sleep into his training a year or two ago.
“If you look at my training plan, sleep is right there along with mileage and pace,” said Dunlap, 42, who typically gets about six or seven hours of sleep during a regular training cycle, but bumps that up to nine or 10 hours in the two weeks before a big race.
“Once I started tracking my sleep, I realized I wasn’t getting nearly enough,” he said. “My performance picked up dramatically when I slept more. It was the difference between finishing barely in the top 10 and finishing on the podium.”