With this week’s “fall back,”—giving us a blissful extra hour—sleep and its role in health is on a lot of minds. New research is showing how varied sleep’s influence is on virtually every aspect of life—from memory to obesity to improving your golf game.
One study, just published in the Proceedings of the National Academy of Sciences, found that the timing of sleep after learning physical activities affects how well people learn when they can observe other people’s actions, but not practice them. The 64 participants had to learn a series of finger tapping exercises by watching them.
Those who slept within 12 hours of observing the task improved their performance—but those whose sleep occurred later than that did not get better. This shows that sleep is necessary for learning by observation and builds on earlier research showing that a good night’s rest is important for learning by practice as well.
The research suggests that people who need to learn a task and have limited opportunity to practice it—for example, those whose movements are limited by stroke—may benefit from timing their activities in the afternoon or evening to take advantage of the learning boost from sleep.
The golf study found that golfers treated for sleep apnea– a condition of disordered breathing during sleep– improved their game by as much as three strokes. This research, which was presented at a recent meeting of the American College of Chest Physicians, looked at 12 golfers who were studied before and after they received treatment with a “nasal positive airway pressure” (NPAP). NPAP helps people with the disorder breathe better at night. After three to five months of treatment, their golf handicap index fell from 12.4 to 11 and they also showed improvement in day time sleepiness.
More new research also confirms the negative effects of changing the timing of sleep—which happens in jet lag and shift work—by looking at how this affects mice. Rockefeller University researchers found that mice which had their biological clocks disrupted by shifts in exposure to light became more impulsive, were slower to learn a maze and gained weight after only six to eight weeks of exposure to less light.
The study also showed changes in chemicals associated with metabolism. That was why– even though the mice were on the same diet as controls who didn’t experience a time shift– they gained weight. If this applies to humans, it’s not a pleasant thought as winter approaches.
Fortunately, as the New York Times sums up another batch of sleep studies, it is possible to pay back a “sleep debt”—although you’ll owe interest, and it’s better to “save up” in advance.
The first study, conducted by scientists at the Walter Reed Institute, found that people allowed to sleep only a few hours each night for a week still showed measurable declines in performance after getting 8 hours a day for three days following the sleep deprivation.
Another study, carried out by researchers at the Karolinska Institute in Sweden, had similar results. After five days of getting only 4 hours sleep, subjects still showed impaired intellectual performance a week later. They’d been able to get eight hours during the recovery week– but the sleep loss still hurt.
The most helpful study, however, found that sleeping 10 hours a night for a week before a harsh week of little sleep allowed people to recover their normal abilities much more quickly.
And, thankfully, research shows that “falling back” has little effect on driving or health: it’s “springing forward” that is connected with increased accidents and disease.