Some people have a "natural alarm clock" allowing them to wake up when they want. This is actually caused by a burst of the stress hormone adrenocorticotropin.
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Dieters who sleep more take off more fat that those who sleep less.
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You can reschedule your sleeping pattern by not eating 12-16 hours before you want to be awake. Upon eating after this time period, your internal clock will reset to a new day, with the time of your first meal being interpreted as "morning".
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Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
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47% of people have a nightmare at least once a month.
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The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
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A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
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