Why do we sleep?

As I have recently experienced a period of increased stress and anxiety which has negatively impacted my sleep, I decided to write a post about the importance of sleep and share with you some tips for getting a good night’s sleep.

So first of all – why do we sleep

Well, the simplest answer is: we sleep so that we don’t die. It is obviously an exaggeration, however a severe and chronic sleep deprivation leads to death. The longest recorded time without sleep is approximately 264 hours, or just over 11 consecutive days. And what happens during this time, you may see by watching “The Machinist” (2004) with Christian Bale.

But seriously, what are the benefits of sleep?

Improved memory and cognition – during sleep there are no external inputs, which gives the brain time to reorganise data, find solutions to problems, process newly learned information and archive memories. This is why often times it is the morning after a good night sleep when we are more creative and our problems look less ‘scary’.

Brain detox – various chemical reactions occurring millions of times every second in our brains, mean there is a lot of ‘metabolic waste’ that must be safely removed to allow our nervous system to function optimally. This is done via a glymphatic system (equivalent of lymphatic system but in our brain) and it happens during sleep.

Sleep gives our bodies time to perform maintenance and repair – cardiovascular system gets a break, blood pressure and heart rate go down, gastrointestinal system snoozes too (if you didn’t have a big meal just before bedtime!) which allows the lining of your gut to be repaired. During sleep the brain releases growth hormones, the body has a chance to repair muscles and other tissues and remove and replace ageing or dead cells. So we literally get younger during sleep and ‘beauty sleep’ is a real thing!

Increased number of research comes out linking circadian rhythm (our 24-hours wake-sleep cycle) to health areas from digestion, through mental health to longevity. If you are interested in this side of things, read about the research of Dr Satchin Panda a circadian biologist at the Salk Institute for Biological Studies in San Diego, California. There is a great podcast with Dr Panda on Dr Chatterjee’s website!

Here are some science based tips for getting a good night’s sleep from an amazing book by Matthew Walker “Why we sleep”. He is a sleep scientist and in his book he actually admits to being “in love with sleep” so he is a little bit biased!

  • 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 bedCoffee, 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 bedHaving 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 bedDon’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 bedThe 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.

As usual, if you have any questions about the above please give me a shout.

Thank you and… good night!



1 thought on “Why do we sleep?”

  1. Pingback: HEALTH FORWARDS! How to look after yourself during the lockdown - bodyofnutrition.co.uk

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