I would never ask anyone how they slept last night unless they happened to be my parents. I never used to pay attention to my sleep either. However, it was rare that I used to sleep well and wake up refreshed without an alarm and those days were memorable. For me and for millions of people all around the world, sleep is boring. There is so much happening when you are awake, why spend time sleeping and be oblivious to the world.
Fortuitously, my boss recommended Mathew Walker’s book Why We Sleep. Matt Walker is a Professor of Neuroscience at University of California, Berkeley and is an avid sleep evangelist. His TED talks on why we should pay attention to sleep are very popular and a must watch for everyone.
Another study showed India is the second most sleep deprived nation with 93% of the population not satisfied with their sleep. We sleep for about 8 hours a day and that’s 1/3 of a day and hence 1/3rd of our entire lives. But the quality of that 8 hours determines how we live the rest of our day and therefore the rest of our lives. Lack of proper sleep takes a toll on physical, mental and social health, worsens pre-existing conditions, increases onset of chronic diseases, takes a toll on our relationships with family and friends. It is a serious problem.
Here is a quick take on Top 10 things that I found very interesting about sleep science –
1. Deep Sleep is real. We have heard of REM or Rapid Eye Movement. Researchers have discovered Non REM (NREM) stage of sleep. There are 3 stages of NREM classified as NREM 1, NREM 2 and NREM 3. NREM 3 is called Deep Sleep phase. We get into the longest deep sleep in our early part of the night. It is difficult to wake someone up during deep sleep phase.
2. We sleep in 90 minutes Sleep Cycles. Yes, it is not in one long shot. We sleep in 4 to 6 cycles in a night, each covering 90 minutes. Why we do this is still under research although lot of theories are proposed. As Matt Walker puts it, the war between the brain and the body is fought and won every 90 minutes.
3. Body goes to work during sleep. This is by far the most intriguing and fascinating part of sleep. Each stage of the sleep has a work cut out. Here is a quick description of the stages:
- a. REM – the brain is very active and puts the body to paralysis deliberately so as to not react to dreams. The brain is making all the neuron connections that enhances learning and memory. It also cleans up bad connections.
- b. NREM 1 – the body is in a very light stage of sleep.
- c. NREM 2 – the body begins to produce sleep spindles that are bursts of rapid rhythmic brain waves.
- d. NREM 3 – the body restores energy, regenerates cells, increases blood supply to muscles, promotes growth and repair of tissues and bones, strengthens the immune system.
4. Each phase of sleep is essential. To get a good night sleep and feel refreshed the next day, it is important to get a minimum quantity of REM sleep and Deep Sleep. Not having enough are symptoms of sleep disorders.
- REM – 20 to 25% of the sleep
- NREM 1 – 2 to 5% of the sleep duration
- NREM 2 – 45 to 55% of the sleep duration
- NREM 3 – 8 to 15% of the sleep duration
5. Sleep behavior is described with Quantity, Quality and Regularity. Sleep deprivation can be due to deficiency in either quantity, quality or regularity. Number of hours of sleep required decreases as we age. 60+ don’t require as much sleep time as adults do. Infants sleep the longest.
6. Sleeping at night is non-negotiable. Human beings are programmed to stay awake during sun light and come night, the brain releases a hormone called melatonin that heralds the onset of sleep. There is also a chemical called Adenosine which is released at night and is responsible for building Sleep Pressure. Caffeine blocks this chemical but after the effect wears out we suffer a crash. Hence a lack of sleep during night time is particularly hard on air travelers, shift workers and night time automobile drivers.
7. Alcohol snatches your dreams. Many people have a habit of drinking alcohol before going to bed assuming it will induce sleep. But alcohol does a lot of damage to a good night’s sleep. As Matt Walker points out, alcohol fragments sleep and therefore is not restorative. Second, due to the nature of alcohol’s contents, when they are processed in the body, they produce chemicals that block REM sleep. No REM phase means, the brain is not writing memory back to permanent storage or making neural connections. Hence, we don’t feel refreshed. This is what we call hangover!
8. Circadian rhythm is not the same for everyone. Circadian rhythm is the cycle of wake time and sleep time; the exact time we wake up, the exact time we go to sleep and the sleep duration. However, it is different for a given age range. Circadian rhythm of teenagers is different from adults. They are programmed to stay up late in the night. One theory is that they use this time to learn the ropes of independence.
9. What you eat can impact sleep. Going to bed too full or too hungry will disturb deep sleep. Diets with more than 70% carbohydrates upset your deep sleep and may have more awakenings during the night.
10. Sleep boosts immunity. Perhaps the most useful discovery of impact of a good night’s sleep is the ability to kill cancer cells. Studies have also shown that taking flu vaccination shots after consistent good nights of sleep create more powerful antibodies. Something for us to think about as we plan to get COVID vaccinations.
I have been paying attention to my sleep behavior over the past few months using a sleep monitoring device. I was not sleeping well earlier and now I am make sure I follow good sleep hygiene. It has increased my productivity and boosted my energy levels.
So, if you want to improve your sleep, the first step would be to take a short simple test that we have put together here. Go ahead and take it to find out how well you are sleeping. If there’s a genuine sleep issue, you could consult a sleep expert and improve your sleep. They’d suggest some lifestyle changes, give you some exercises and it sure will help you sleep better.
Make Sleep a Priority today.