Friday, December 07, 2007

Can you get by on 4 hours of sleep

“Some research suggests that while seven to eight hours a night is healthy, under five hours or more than eight is unhealthy, and linked to disorders such as heart disease, depression, diabetes and high blood pressure.”

For 264 hours, Randy Gardner did not go to sleep. He felt tired, but each time the urge to rest his head on a pillow came upon him, he played basketball and, after 11 days and nights in January 1964, he broke the world record for sleeplessness. He thanked his supporters, held a press conference and promptly passed out.

The only time it can rest is during sleep The dominant theory is that sleep is a time for the brain to store memory. The idea is that during sleep the brain, in effect, goes offline to file the events of the day. Another theory is that the brain is a complex organ that needs the downtime provided by sleep to recover from the stresses of waking hours. “While we are awake, the higher centres of the brain are working flat out,” The question is what would happen if you were to change your sleep pattern from 7-8 hours to 4?

If you sleep for:

4 HOURS Your immune system becomes compromised. Researchers at the University of Chicago exposed sleep-deprived students – four hours a night for six nights – to flu vaccine, their immune systems produced only half the normal number of antibodies. Stress levels rose, raising heart rates and blood pressure.

5 HOURS Your risk of diabetes increases. Research at Boston University School of Medicine suggests that those who have less than five hours a night were 2.5 times more likely to develop diabetes compared with those having seven to eight. You also increase the risk of being overweight. According to research at Bristol University, the rise in obesity may be partly because of the reduced amount of time we spend asleep. People who sleep for five hours were found to have 15 per cent more ghrelin, a hormone that increases feelings of hunger, than those who slept for eight hours. They were also found to have 15 per cent less leptin, a hormone that suppresses appetite.

6 HOURS Watch out for high blood pressure. A study reported in Hypertension suggests that those who sleep less than six hours a night had more than double the risk of high blood pressure.

And if you've been awake for:

10 HOURS Levels of the stress hormone cortisol begin to rise. There may also be changes in blood pressure.

12 HOURS The likelihood of having a car accident more than doubles. Heart rate begins to slow.

17-28 HOURS Speed in mental tasks slows to the equivalent of someone who has drunk the drink-drive legal limit of alcohol.

24 HOURS Risk-taking behaviour increases. Verbal fluency declines.

48 HOURS Effectiveness of immune system declines.

53 HOURS Ability to make moral judgments declines.

72 HOURS Speed and accuracy in computer tests drop to 30 per cent of normal.

85 HOURS Brain activity declines significantly.

11 DAYS Longest documented period of voluntary sleeplessness is 264 hours. No long-term harmful effects found.

Sources: US Federal Highways Commission; University of New South Wales; University of California, San Diego; North Carolina University; Walter Reed Army Institute of Research; Johns Hopkins University

Some famous people who claimed they can function on 4 hours or less:

1. Jay Leno – four hours
"He subsists on four hours' sleep per night. Out of fifty-two weeks, he gets
four weeks off, during which time he is miserable. "I hate those weeks off," he
tells me. "To me, a week's vacation just means you're now a week behind."

2. Madonna – four hours
"Madonna has revealed she only grabs four hours' sleep a night because she
constantly worries about everything that is going on her life."

3. Florence Nightingale – four hours
"Florence Nightingale only slept four hours a night"

4. Anton Ballard – four hours
"Ballard keeps pushing himself to get better. He averages around four hours of
sleep per night, and works about 12 hours each day between his meat counter and
his studio."

5. Michelangelo – four hours
"Both aboriginal peoples and highly creative people (such as Thomas Edison and
Michelangelo) rarely sleep for more than four hours at a time."

6. Napoleon Bonaparte – four hours
"Napoleon Bonaparte learned to live with the fact that he was only existing on
three or four hours sleep a night and got on with his grand schemes."

7. Bill Clinton – five to six hours
"President Clinton grabs 5-6 hours"

8. Winston Churchill – six hours
"It was claimed he only spent 6 hours in bed every night. However, he wrote
that one needs to take a complete nap every afternoon, to get fully undressed
and really go to bed. No "halfway measures". He claimed the reward was to "get
two days in one - well, at least one and a half, I'm sure." He claimed this nap
was absolutely neccessary to cope with his responsibilities during the war. His
naps were 1.5 to 2 hours long, for a total of about 8 hours a day!"

9. Nikola Tesla – two hours
"He is said, by some of his followers, to only have slept 2 hours a day. He was
definitely a night owl. But his staff has told of him taking many naps during
the day. And it seems he may have been narcoleptic, and able to sleep with his
eyes open."

10. Leonardo Da Vinci – 15 mins every four hours (ie. 1.5 hours)
" It was said that he would sleep just 15 minutes of every four hours."

11. Margaret Thatcher – four hours
"Margaret Thatcher, the former prime minister, was famous for getting by on
only four hours a night."

12. Martha Stewart – four hours
"“There’s not enough time in the day,” complains the woman who says she needs
no more than four hours’ sleep a night."

13. Thomas Edison – four hours
"Thomas Edison slept 3-4 hours at night, regarding sleep as a waste of time"

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