Sleep — Why you should never cut it short
We all spend ⅓ of your life sleeping. Have you ever wondered why? If you think about it from a practical perspective, we are very vulnerable and unsheltered during sleeping. So it makes sense to know a little bit more about why we sleep, what we need it for and how you can make sure that your sleep is effective.
In this post I will highlight briefly the mechanism behind sleeping, why you should never cut your sleep short and what you can do to increase your sleep quality. So let’s dive right in.
Thought experiment — Pulling an all-nighter
Let’s do a little thought experiment: You go out and party until late at night. You and your friends decide that it would be a great idea to wait until the sunrise before going to bed, just to get some fancy instagram photos (#earlybird #sixam #sleepisfortheweak). It is only 2am, the vibes are still good, and so you decide to go with it and do it. Unfortunately, most of the bars close at that time, so you need to hang out outside until 6am.
In the beginning, staying awake seems to be a piece of cake. But then around 4am you all get super tired and you just want to lay down and sleep for little while. Bravely, you all make it through until 6 and all the suffering pays off for the one instagram post. #IdoItForThePics.
But wait — out of a sudden, as soon as the sun had risen, it feels like the tiredness has been blown away. Isn’t that a little bit suspicious when just two hours earlier, you were terribly tired?
Process-S and Process-C
The above example is excellent for explaining that sleepiness consists of two separate mechanisms.
The first is the sleep drive, or Process-S, which basically measures the absolute time you were active. The only way to reset your sleep drive is to actually sleep.
Your second sleep mechanism is the circadian rhythm, which is a signal that tells you when it is time to be awake and when it is time to be asleep. However, this signal is periodic and does not shift when you stay up late.
Getting back to the example before, at 4am, your circadian rhythm is on it’s peak to tell you to be asleep, while your sleep drive has built up A LOT of “sleep pressure” on your body. This is the hardest time for you to stay awake. Then, later around 6am after sunrise, your circadian rhythm signals that it is time to be awake again, lowering the effect of Process-S on your body.
Why you should never cut short on sleep
In this section, you will learn about the science that strongly suggest to never cut your sleep short. Specifically, I will highlight three studies that underline the effect of sleep on learning, attention, and appetite.
The effect of sleep on learning
A study showed that a 90 minute nap can increase the short-term learning capabilities by 20%.
The studied divided a group of healthy individuals into a “nap” and “no-nap” group. Both groups were tasked to learn one hundred face-name pairs. Then, the “nap” group was granted a 90 minute nap, while the “no-nap” group remained active. 6 hours after the learning task was conducted, the learning task was repeated with both groups. The “nap” group showed superior performance by 20% on average, suggesting that a nap can significantly improve your ability to remember.
There is a lot more evidence on the beneficial effect of sleeping to learning. Interestingly, the result was already known in 1924.
The effect of sleep on attention
Many studies have investigated how your responsiveness and attention changes when being restricted to only a certain amount of sleep. One particular experiment compared the effect of alcohol to the effect of sleep deprivation. An Australian group divided a pool of candidates into two groups. They got one group drunk (under medical supervision, of course) to the 0.08% blood alcohol legal driving limit, the other group was simply given a restricted amount of sleep. After being awake for 19 hours, the sleep deprived group showed the same lack of attention as the drunk group. In other words: being sleepy is exactly like being drunk. In addition, you always underestimate how tired you really are, similar to being drunk.
The effect of sleep on your appetite
Yes, sleeping directly impacts your appetite. To claim this result, a study had to carefully control the food intake, physical activity and amount of sleep of all participants. All parameters of the study were kept constant (constant amount and type of food, constant physical activity) except the sleep time. In one week, the participants were granted 8 hours of sleep, whereas in another week, they were only granted 4 to 5 hours of sleep each day. Already after the second night of sleeping short, the appetite of participants increased rapidly.
In case you are curious why: your appetite is controlled by two hormones, Leptin and Ghrelin, which are signalling fullness and appetite respectively. Not getting enough sleep causes an imbalance in between those two hormones, leading to a stronger feeling of appetite. So if you are looking to lose some weight, I strongly recommend to you to sleep enough.
Wrapping it up: there is no evidence that whoever claims to be just fine with 6 hours of sleep, he cannot possibly be on best version of himself. Take care of getting 8 hours of sleep each night, and you will see significant improvement in your mental capabilities and the number you see on your scale.
Sleep Hacks -12 tips for better sleep
This blog would not be what it claims to be without some actual hands on advice on how to improve your routine. Just like we are not cutting short on sleep, we are not cutting short on advice to improve your sleep. One personal piece of advice: change your bedding every week. It is a tiny hack with big gains.
The following tips are from the National Institute of Health (NIH) Summer 2015 article “Tips for Getting A Good Night’s Sleep”.
If you are looking to improve your sleep quality, try these things exactly in this order, once at a time. Just a fair warning: the best (and probably hardest) way for better sleep is to simply get up and go to bet at the same time every day.
- Stick to a sleep schedule. Go to bed and wake up at the same time each day. As creatures of habit, people have a hard time adjusting to changes in sleep patterns. Sleeping later on weekends won’t fully make up for a lack of sleep during the week and will make it harder to wake up early on Monday morning.
- Exercise is great, but not too late in the day. Try to exercise at least 30 minutes on most days but not later than 2–3 hours before your bedtime.
- Avoid caffeine and nicotine before bed. Coffee, colas, certain teas, and chocolate contain the stimulant caffeine, and its effects can take as long as 8 hours to wear off fully. Therefore, a cup of coffee in the late afternoon can make it hard for you to fall asleep at night. Nicotine is also a stimulant, often causing smokers to sleep only very lightly. In addition, smokers often wake up too early in the morning because of nicotine withdrawal.
- Avoid alcoholic drinks before bed. Having a “nightcap” or alcoholic beverage before sleep may help you relax, but heavy use robs you of deep sleep and REM sleep, keeping you in the lighter stages of sleep. Heavy alcohol ingestion also may contribute to breathing impairment at night. You also tend to wake up in the middle of the night when the effects of the alcohol have worn off.
- Avoid large meals and beverages late at night. A light snack is okay, but a large meal can cause indigestion that interferes with sleep. Drinking too many fluids at night can cause frequent awakenings to urinate.
- If possible, avoid medicines that delay or disrupt your sleep. Some commonly prescribed heart, blood pressure, or asthma medications, as well as some over-the-counter and herbal remedies for coughs, colds, or allergies, can disrupt sleep patterns. If you have trouble sleeping, talk to your healthcare provider or pharmacist to see whether any drugs you’re taking might be contributing to your insomnia and ask whether they can be taken at other times during the day or early in the evening.
- Don’t take naps after 3 p.m. Naps can help make up for lost sleep, but late afternoon naps can make it harder to fall asleep at night.
- Relax before bed. Don’t overschedule your day so that no time is left for unwinding. A relaxing activity, such as reading or listening to music, should be part of your bedtime ritual.
- Take a hot bath before bed. The drop in body temperature after getting out of the bath may help you feel sleepy, and the bath can help you relax and slow down so you’re more ready to sleep.
- Have a good sleeping environment. Get rid of anything in your bedroom that might distract you from sleep, such as noises, bright lights, an uncomfortable bed, or warm temperatures. You sleep better if the temperature in the room is kept cool. A TV, cell phone, or computer in the bedroom can be a distraction and deprive you of needed sleep. Having a comfortable mattress and pillow can help promote a good night’s sleep. Individuals who have insomnia often watch the clock. Turn the clock’s face out of view so you don’t worry about the time while trying to fall asleep.
- Have the right sunlight exposure. Daylight is key to regulating daily sleep patterns. Try to get outside in natural sunlight for at least 30 minutes each day. If possible, wake up with the sun or use bright room lights in the morning. Sleep experts recommend that, if you have problems falling asleep, you should get an hour of exposure to morning sunlight and turn down the lights before bedtime.
- Don’t lie in bed awake. If you find yourself still awake after staying in bed for more than 30 minutes or if you are starting to feel anxious or worried, get up and do some relaxing activity until you feel sleepy. The anxiety of not being able to sleep can make it harder to fall asleep.
- See a health professional if you continue to have trouble sleeping. If you consistently find it difficult to fall or stay asleep and/or feel tired or not well rested during the day despite spending enough time in bed at night, you may have a sleep disorder. Your family healthcare provider or a sleep specialist should be able to help you, and it is important to rule out other health or emotional problems that may be disturbing your sleep.
Further Reading
Inspiration for this post and why I changed my sleeping habbits comes from Matthew Walker and his book “Why we sleep”: https://www.amazon.de/Why-We-Sleep-Science-Dreams/dp/0241269067.