Jonathan Daniel/Getty Images
Linebacker Joe Odom #59 of the Chicago Bears takes a nap in his new locker during the media tour the locker room of the rebuilt Soldier Field stadium, home to the NFL Chicago Bears and the MLS Chicago Fire, on September 18, 2003 in Chicago, Illinois.
Two new studies show that getting more sleep at night can improve everything from a football player's 40-yard dash time to a preschooler's vocabulary and math skills. The results are the latest in a growing body of research that highlights the perks of getting a good night's sleep.
New research adds to a growing body of evidence showing the perks of a good night's sleep.
A study from researchers at Stanford University finds that extra hours of sleep at night can help improve football players' performance on drills such as the 40-yard dash and the 20-yard shuttle.
"The goal was to aim for 10 hours of sleep per night," says Cheri Mah of the Stanford Sleep Disorders Clinic. At the beginning of the season, Mah found that the players had moderate levels of daytime fatigue, even though they thought they were getting enough rest at night. Seven players were included in the study.
It's not easy to convince college students to add hours of sleep to their schedules each day. "It's a lot to ask," Mah says, but throughout the season she was able to document a significant extension of nighttime sleep.
Early in the season, the players' average 40-yard dash time was 4.99 seconds. But after six weeks of extra ZZZs, the average time dropped one-tenth of a second -- to 4.89 seconds.
"That could mean millions in the NFL," says Dr. Tim Church of the Pennington Biomedical Research Center at Louisiana State University. "A tenth of a second is a huge, huge difference from a performance standpoint."
As the players' performance on drills improved with the extra sleep, their levels of daytime fatigue dropped dramatically. And the scores on vigor tests improved, too.
"It's not a surprise," Church says. He adds that the players' workouts are so extreme and intense that "when you give them a little extra time to recover, you see additional benefits."
It's hard to say how the connection between more sleep and improved physical performance may translate to weekend warriors -- or middle-age folks who are just trying to hold onto a nine-minute jogging pace.
The take-home message here, Church says, is that this is just one more example of how sleep makes a difference.
Sleep And Preschool Success
The benefits of adequate sleep extend far beyond what's now being documented on athletic performance. And when it comes to teaching good sleep hygiene, it seems parents can never start too early.
One new study that explored the sleep habits of preschool-age children finds that bedtime rituals and rules play a unique role in the development of 4-year-olds.
"This is a good time to look at things like early learning and brain development," says researcher Erika Gaylor of SRI International, a nonprofit research institute in Menlo Park, Calif.
She analyzed a federal survey of some 8,000 families in which parents were asked a slew of questions about bedtime. The survey was ongoing -- from the time their kids were 9 months old through the start of kindergarten. Parents were surveyed several times throughout this period.
The researchers asked questions such as, "What time does your child go to bed?" and "Do you as parents have a rule about bedtime?" Researchers followed up with home visits, during which they conducted one-on-one assessments to measure math and language skills.
"What was really surprising was that having a rule about bedtime was associated with higher scores on language and math skills," Gaylor says.
Children of parents who reported having a rule about bedtime scored about 6 percentage points higher on an assessment of their vocabulary compared with children whose parents did not report a rule about bedtime. They scored 7 percent higher on assessments of early math skills.
They were small but significant differences. And researchers say the study is yet another example of the power of a good night's sleep.
Both of these studies are being presented this week at the annual SLEEP conference, which is a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society. Copyright 2010 National Public Radio. To see more, visit http://www.npr.org/.