- Before the invention of the light bulb, Americans slept an average of 10 hours a night.
You may forgive yourself for not getting enough sleep, but your body doesn’t forget. The missing Zs that you’ve cheated yourself out of actually accumulate over time to form what researchers call “sleep debt” — a deficit that continues to affect alertness and performance even when you do get a good night’s sleep. The good news is that sleep debt can be paid off with some extra down time and the development of good sleep habits.
Better news yet is that naps are scientifically justified. According to Dr. Gregory Belenky, director of WSU’s Sleep and Performance Research Center in Spokane, the latest research shows that daytime naps are just as good as getting your required amount of sleep in one stretch. “From what we know, dividing your sleep is either the same or better than consolidated sleep,” he says. “It may even be more effective, in terms of sustaining alertness and performance.” Thirty to 45 minutes in the afternoon should do the trick.
No one can say what the optimal amount of sleep should be for any particular individual, but conventional wisdom is that healthy adults need seven to eight hours of sleep in a 24-hour period to adequately recuperate.
“The average American appears to not get enough sleep,” Belenky says. Citing a recent poll, he says the average American is in bed for 6 hours and 55 minutes per night. Subtracting time for falling asleep and waking up, it’s probably closer to six and a half hours of actual sleep time.
Over time, sleep deprivation takes its toll. According to the National Sleep Foundation (NSF), short sleep duration has been linked with: increased risk of vehicle accidents; a greater likelihood of obesity due to increased appetite; and an increased risk of health issues from diabetes and heart problems to psychiatric conditions. “The performance degradation is cumulative up to a point, then it appears to stabilize at a lower level,” Belenky says. “That’s how people can tolerate being chronically sleep restricted — they sort of adapt.” People get so accustomed to being tired that they just assume it’s normal.”
To pay off that sleep debt and become a well-rested individual, the NSF says you should:
- Develop a consistent sleep schedule
- Create a regular and relaxing bedtime ritual
- Create a dark, quiet, sleep-friendly environment
- Use a comfortable mattress and pillows
- Avoid “sleep-stealers” like watching TV, reading or using a computer in bed
- Finish meals two to three hours before bedtime
- Avoid caffeine and alcohol close to bedtime
While the effects of sleep deprivation have been well documented, there is still much to learn. “The most outstanding thing I’ve discovered is what we don’t know yet: that is, what goes wrong in the brain with prolonged waking and how sleep fixes it,” Belenky says. “We really don’t know.”