Many aspects of sleep are still a mystery. Also to the scientists that study it. It is strange we know so little about this incredibly healthy and healing ‘thing’ we do for one-third of our lives. In this blog I talk about ten things you probably didn’t know about sleep.
1. Most adults do not get enough sleep
Two-third of adults in developed nations fail to sleep for the recommended eight hours. We all know one of the main causes: technology. It probably started with the invention of electricity and the electric lights (or maybe even before that). And it has gotten worse with every invention. These days, the tablets and smartphones are steeling our precious sleep and that of our teens.
2. We all have an internal (alarm) clock
While we sleep, our brain is still capable of tracking time with incredible precision. We may not consciously experience time but our brain still tracks time at a non-conscious level when we are asleep. That is why you often wake up a few minutes before your alarm clock beeps. Your brain knows that the alarm is about to go off.
3. The shorter we sleep, the shorter we live
Sleeping less than we are supposed to damages many processes in our body. It increases the chances of getting diseases like: cancer, Alzheimer’s, diabetes and cardiovascular disease.
Not getting the right amount of sleep makes us tired and also triggers hormones that make us feel hungry. We eat when we don’t need to and gain weight.
Finally, sleeping less damages all kinds of processes in our mind and we are more likely to develop psychiatric conditions.
4. Most people are morning types
Morning larks have their peak of wakefulness early in the morning and become sleepy early at night. Forty percent of all people are morning types.
Night owls prefer going to bed late and usually wake up late the following morning. Thirty percent of all people are evening types.
The remaining thirty percent of people are somewhere in between morning and evening types.
5. Melatonin doesn’t generate sleep
Many people think that melatonin somehow generates sleep. This is a misconception: melatonine has little influence on the generation of sleep itself but it does help regulate the timing of sleep.
6. Readjusting to another time zone takes one hour a day
For every day you are in a different time zone, you can only readjust by about one hour. That is why your body needs a whole week to readjust to a seven hour jetlag.
7. After seven hours you may still have 50 percent of the caffeine in your body
Caffeine has an average half life of 5 to 7 hours. When you have a cup of coffee at 8 PM, 50 percent of the caffeine may still be in your body when you are in bed at 3 AM.
8. The brainwaves of dreaming and being awake are very similar
REM sleep is the state of sleep we are in when we are dreaming. Scientists discovered that the brainwaves our brains generate when we are are in a REM state of sleep are very similar to the brain waves we generate when we are wide awake.
9. All animals sleep
All insects, fish, amphibians, reptiles, bird and mammals sleep. However, we are not sure they all dream. But all mammals probably do since they appear to have REM sleep (the state of sleep we are in when we are dreaming).
10. Some animals can sleep with half a brain at a time
Some animals sleep with only half their brain. The other half stays awake to look for threats or to be able to float in the water or lie steady on a branch of a tree for example. After a while they switch brain sides and let the other half sleep.