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.
15
Lack of water is the #1 trigger of daytime fatigue.
148
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Those who get out of bed by 7am are more likely to be thinner and happier.
20
The harder you concentrate on falling asleep, the less likely you are to fall asleep.
34
The higher someone’s I.Q. the more likely they are to be sleep deprived.
29