Do you think you can function on four hours of sleep? What about if you got four hours for two nights? What if you only got four hours of sleep every night for a week -- do you think you could function normally then?
The answer for almost all of us is no. Most of us need about six to eight hours of sleep a night -- the exact number is different for each us. While we may claim that we can function on five or so hours of sleep, the truth of the matter is that if you're only getting five hours of sleep each night, you are very, very sleep deprived.
Unless, of course, you find out you are aren't. An article in the Wall Street Journal is one of many that have recently discussed a group of people called either "super sleepers" or "short sleepers" -- people who actually need fewer than six hours of sleep each night. True short sleepers not only can function normally on this amount of sleep, but they also generally wake up naturally after about four or five hours. While many people claim or wish that they were in this population, only 1 percent to 3 percent of people are actually short sleepers.
Researchers think that this ability to function on such little sleep is likely a genetic anomaly (sorry, you can't teach yourself to be a short sleeper), and the differences don't end with the amount of sleep needed:
- Short sleepers have different circadian rhythms from most people.
- They also tend to be more upbeat and optimistic.
- They have a higher tolerance for physical and psychological pain.
- While sleep deprivation usually correlates with obesity and diabetes, short sleepers tend to have higher metabolisms than most people, and on average are actually thinner.
It seems sort of unfair that these short sleepers can sleep for so little time and actually have more energy than those of us who need six to eight hours every night. But this ability is very rare -- in fact, the researcher mentioned in the Wall Street Journal article said that he had only identified about 20 actual short sleepers. Just as you don't hear about people who drink, smoke and eat poorly living to the ripe old age of 100 very often, you don't hear about too many people who live like vampires and escape the ravages of that lifestyle. Those who claim they "get by" on very little sleep are likely fooling themselves, but their bodies won't fool them for too long. Eventually, that lack of sleep will show up somewhere in the way they look or feel (or both). And ultimately, their health will suffer.
If you really think you might be a short sleeper, consider one of the questions the researchers used to identify members of this group of sleeping elite: If you have the chance to sleep longer on weekends or vacation, do you still only sleep five hours a night?
If you sleep seven or eight hours when you can, chances are high you aren't a short sleeper -- and you really need those seven or eight hours every night of the week as well.
Michael J. Breus, Ph.D.
The Sleep Doctor™
"Everything you do, you do better with a good night's sleep"™