Importance of a good sleep and how it affects our health
- September 13, 2018
Through our lives, we spend over 200,000 hours or 22 full years asleep! This may seem like a lot of time spent doing nothing, but quality sleep is incredibly important to health and longevity. Understanding the importance of sleep and how it relates to our health, as well as what we can do to improve the quality of our sleep can go a long way in improving the quality of our lives.
The stages of sleep
There are five stages of sleep- Stage 1, stage 2, stage 3, stage 4 and the REM stage.
Stage 1: This is the transitional phase between wakefulness and sleep. During this stage, your mind slowly starts to drift off and you float in and out of consciousness.
Stage 2: This stage occurs when you fall asleep and become unaware of your surroundings. Your body’s internal temperature decreases and heart rate slows down, as your breathing falls into a natural rhythm.
Stages 3 and 4: Stages 3 and 4 are what we refer to as ‘deep sleep’. In stage 3, brain waves slow down, breathing slows, blood pressure decreases and muscles become completely relaxed. During these restorative stages of sleep, blood flow to your muscles increases, growth hormones are released, and tissues can repair themselves. People who tend wake up during stages 3 and 4 will find themselves disoriented for a few minutes and would want to hit the snooze alarm!
REM sleep: REM sleep gets its name from the Rapid Eye Movement that occurs during this stage. A REM stage typically occurs every 90 minutes after you fall asleep for between 10 and 25 minutes, increasing each subsequent time in a bout of sleep. During these stages of sleep, your eyes move around, your brain is active, and your body is relaxed. This is when dreams occur. This type of sleep energizes your body and brain and helps you feel alert and focused during the day.
A typical night of sleep involves moving through these stages in cycles, going from stage 1 through 4, into REM sleep and back to stage 1. It’s best to wake up during stage 1 to feel the most refreshed and a good approximation is to set your alarm in multiples of 90 minutes (1.5 hours) from your bedtime.
Why is sleep so important?
Sleep regulates our “internal clock” known as our ‘Circadian rhythms’, which regulate everything from the time we feel tired to the levels of our hormones through the day. A special class of nerve cells in our eyes detect brightness and trigger a part of our brain (the suprachiasmatic nucleus or SCN) to reset our body’s internal clock, bringing it in sync with the day-night cycle. The SCN does this by controlling the secretion of melatonin, which regulates various aspects of our sleep/wake cycle.
The circadian rhythm is associated with as much as 15% of our genes, as a result of which sleep has a direct role in a number of systems and processes, including:
How much sleep do we need?
Sleeping in one block for 7 – 9 hours is believed to be the result of industrialization rather than driven by our biology. Historically, humans are believed to have slept in two or more blocks of 3-4 hours, just like other mammals. However, given that most of us (and our professions) are more tuned to ‘monophasic’ sleep, a good night’s sleep would be defined as 5-6 full sleep cycles, from stage 1 through REM sleep. However, it is important to note that individual sleep requirements vary based on factors such as age, lifestyle, activity levels and stress, with some individuals requiring far less sleep than others.
Signs that we are getting sufficient quality sleep include:
1] Falling asleep within 15-20 minutes of lying down to sleep.
2] Regularly sleeping a total of seven to nine hours in a 24-hour period.
3] Sleeping continuously — not lying awake when you wish to be sleeping.
4] Waking up refreshed
While there may be variations based on isolated events like a stressful day or that late night cup of coffee, most (if not all) of these four guidelines should apply. If not, it would be advisable to check with a healthcare professional to address any underlying issues or lifestyle changes that could improve the quality of your sleep, given the vital role it plays in ensuring good health.
How to get more and better sleep
A few simple tips can ensure that we optimize the quality and quantity of our daily sleep. These include:
Light suppresses melatonin production and disrupts the sleep cycle and the reason why it’s easier to sleep in a dark space. Blue light from mobile screens, LED TVs etc. disrupts melatonin production, tricking our brains into feeling that its daytime. Avoid looking at bright screens beginning two to three hours before bed. If you work a night shift or use a lot of electronic devices at night, consider wearing blue-blocking glasses or installing an app that filters the blue/green wavelength at night on your devices. Expose yourself to lots of bright light during the day, which will boost your ability to sleep at night, as well as your mood and alertness during daylight.
Neglecting sleep through the week and trying to catch up on the weekends doesn’t work. Our bodies quickly adapt to our habits, for better or worse, and sleeping for short periods of time followed by two days of excess sleep is recognized as a constant disturbance in the cycle. In fact, research has shown that sleeping in on the weekend actually makes you more tired in the following week. Setting a routine to sleep at about the same time and for the same duration, every night is ideal.
Studies have shown that being inactive is associated with poorer sleep, and conversely, getting exercise during the day may help you sleep better at night. Intense exercise at night may delay the amount of time it takes you to fall asleep, and its best to avoid workouts very close to bedtime.
Adopting a relaxing routine before bed can help you get in the mood to sleep. For example, listening to calming music or taking a bath before bedtime. Sleeping in a quiet, dark room at a comfortable temperature can help you sleep better. Being too active before bed, too warm or in a noisy environment is linked to poor sleep.
Studies have linked caffeine, alcohol and nicotine use to poorer sleep quality. Try to avoid caffeine, especially late in the day.
Limiting fluid consumption at night will lessen your need for bathroom trips which may disrupt sleep.
A nap of less than 30 min duration during the day promotes wakefulness and enhances performance and learning ability. Short naps do not affect night sleep unless they’re very close to bedtime.
Nutrition plays a role in all aspects of our health, including sleep. Deficiencies in vitamin B12, B6 and Magnesium have been linked to trouble sleeping, while Vitamin D3 has been shown to improve quality of sleep. Proteins rich in the amino acid tryptophan, a precursor to melatonin, have been shown to promote sleepiness.
Dang-Vu TT, et al. Pediatr Rehabil 2006 Apr-Jun; 9(2): 98-118.
Maquet P, et al. Science 2001 Nov 2; 294(5544): 1048-52.
Sharma S and Kavuru M. Int J Endocrinol. 2010; 2010: 270832.
Van Cauter E, et al. Endocr Rev 1997 Oct; 18(5): 716-38.