Posted on 23 December 2022
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In part 1, we discussed the different phases of sleep, how they progress throughout the night and why they’re important. In part 2, we went over the most important factors when it comes to controlling sleep and alertness. Now it’s time to put this knowledge to use: the following 15 tips should not only help you to enter sleep more easily and spend more time in the deeper restorative phases of sleep, but also to remain more alert throughout the day. These tips are in approximate order of increasing effectiveness. The earlier tips tend to be general advice about best practices for good sleep, while the later entries are about using your environment to manipulate your sleep-wake cycle.
This is more ‘advice about the advice’ than a tip in and of itself, but it’s worth highlighting anyway. If you remember part 1 of this series, you will be aware that not all sleep is created equal. Even if you’re getting a full 8 hours of sleep every night, the amount of time spent in the more restorative stages of sleep could vary depending on factors like the temperature of your bedroom, how much caffeine is in your system and how recently you looked at a screen. The quality of your sleep isn’t something you can objectively measure well without strapping electrodes to your head, so don’t assume that a change you made to your sleep routine isn’t helping just because you don’t notice a change. Studies suggest that some practices, such as adjusting the temperature of your bedroom, primarily affect the quality and not the quantity of your sleep.
If you find yourself lying in bed and unable to sleep, you might think that the best course of action is simply to wait it out. However, it might actually be safer to get up and do something else if you’ve been unable to get to sleep for over 20 minutes or so, returning to bed only once you start to feel sleepy. Building psychological associations is an important and often ignored step to getting good sleep. Some sleep experts warn that lying awake in bed for too long could ‘train’ your brain to associate your bed with wakefulness, making it harder to sleep in the future. Sometimes it’s better to allow more of the ‘sleep pressure’ discussed in part 2 to build up before returning to bed. If you do decide to follow this advice, be sure to avoid light as much as possible, and avoid cognitively stimulating tasks and exercise.
Daytime naps can be a double-edged sword. On the one hand, there is data showing that naps as short as 10 minutes could be beneficial for various aspects of your health, including memory and cardiovascular health. There is even some evidence we evolved to nap. Humans have a natural tendency to experience a lull in energy levels in the mid-afternoon. In some hunter-gatherer societies, it is common to take a nap of up to 90 minutes (about the length of one sleep cycle) in the afternoon during summer, and then sleep for just 6.5 hours at night. However, this is not universal and we still don’t really know how our ancestors slept prior to societal constraints.
Unfortunately, naps may alleviate some of the sleep pressure that builds up the longer you are awake, and this could make it harder to fall asleep at night. Naps can also make you feel groggy if you nap for too long. This is called ‘sleep inertia’ and usually occurs when you wake up in the middle of one of the deeper sleep phases.This is the reason that keeping naps brief is usually recommended. Despite these drawbacks, most sleep experts suggest that naps are likely to be beneficial unless they are preventing you from falling asleep later on.
If possible, you should try to ensure that your bedroom is dedicated primarily to sleep. Put some effort into setting up your bedroom to promote relaxation. Don’t sleep in the same room in which you work or study, for example. It’s important to build a psychological association between your bedroom and sleep while avoiding forming associations with stressful activities. It’s also important to make sure that your bedroom is free of light during the night. For example, make sure you have blinds or curtains that properly block artificial light sources from outside. Even dim light during the night can not only make getting to sleep harder, but can also disrupt your sleep cycles while you are asleep.
Though it may seem obvious, it’s easy to make the mistake of thinking that getting to bed at 11pm and waking at 7am will get you 8 hours of sleep. In reality of course, you are likely to be asleep for only 7 out of those 8 hours. The proportion of time in bed spent sleeping is known as sleep efficiency, and most people have a sleep efficiency of around 85-90%. This means that to get 8 hours of sleep, most people will need to plan for about 9 hours in bed. It’s worth figuring out your own sleep efficiency so that you can ensure you are actually getting the amount of sleep you think you’re getting.
Most people know that you shouldn’t be staring at screens late at night. However, you might remember from part 2 that the changes in lighting as the Sun sets act as a reference point for the onset of sleep. This means that unnatural light sources can interfere with the sleep-wake cycle throughout the evening. Unfortunately, melatonin release is much more sensitive to light in the evening than it is in the morning, which means that exposure to even small amounts of light can interfere with it. We’re not suggesting that you live by candlelight after sunset, but consider dipping and reddening the lights where possible.
If you’re having trouble getting to sleep, dietary supplements can sometimes be very helpful. The most effective and well supported supplement for promoting sleep is melatonin, which most studies suggest can improve sleep quality and duration and appears to be safe for adults. There are many other supplements that may aid sleep, such as magnesium and glycine, but the evidence for some of these is conflicting and some may also have side effects. It’s always best to consult with a doctor before taking a new dietary supplement.
What you eat and when you eat it can have a powerful effect on the sleep-wake cycle by affecting the levels of various hormones and neurotransmitters. At the minimum, you should try not to go to bed hungry, but also avoid eating within 2-3 hours of going to bed. The stress hormone cortisol plays a role in regulating appetite and its levels increase when you’re hungry, preventing you from sleeping well (incidentally, cortisol is one of the reasons why stress can make you overeat). Food should be avoided within a few hours of bed, because activity of the digestive system can interfere with sleep.
It is, however, possible to exploit the link between food and sleep further. There is evidence that diets that drastically cut carbohydrate intake (such as ketogenic diets) and some forms of fasting can improve sleep at night and alertness during the day. This effect isn’t well understood, but seems to be mainly due to the effects of low carbohydrate intake on various neurotransmitters and hormones. Such diets do come at a cost, as they can also disrupt your sleep initially (such as in the case of ‘keto insomnia’). It’s also important to be aware that these diets might not work the same way for everyone, and sleep probably shouldn’t be your only reason for trying them. As always, consult with a doctor before altering your diet drastically.
You should try to get to sleep, wake up, exercise and eat at the same times from day to day. Keeping the timing of these events consistent helps to entrain and reinforce the circadian rhythm, which in turn helps initiate sleep at the same time each night. It might sound obvious, but meals and exercise should be timed relative to when you are asleep. If you decide to start waking up and going to bed an hour earlier, you should also eat and exercise an hour earlier.
We’ve all heard this advice before – experts have been giving it for years, but perhaps not for all of the right reasons. Studies show that light emitted by these devices, particularly blue light, can reduce melatonin levels and reduce the quality of our sleep. However, some experts suggest that light is only part of the problem, and that the ability of this technology to stimulate us mentally could be the main culprit for their effects on sleep. Most things you can do on a phone or tablet are designed to keep the user as engaged as possible, not to help you relax. The question of whether such devices harm our sleep mainly because of the light they emit, or because they are ‘activating’, has yet to be resolved conclusively by research.
Many experts also caution against using electronic devices first thing in the morning. Not only can they throw off your entire morning routine, but they also expose you to an immediate source of stress and can interfere with the natural spike in cortisol that usually occurs 30-45 minutes after waking. We don’t really know how this affects sleep or alertness later during the day, though.
Finally, though this may be ‘dangerous’ advice for some people, consider getting rid of your alarm clock or at least covering up the time if you find that looking at the time keeps you awake. Knowing that you’ve been awake for 2 hours or that you woke up an hour before your alarm won’t help you get back to sleep, and many people find that it makes it harder.
These three drugs can all have a significant impact on your sleep quality, even though you might not notice it. Caffeine is the world’s most consumed drug, and many people rely on it to keep them alert during the day. An increasing number of studies also suggest that regular caffeine consumption in tea and coffee could have some quite significant health benefits. However, there are a few rules you should follow to ensure caffeine doesn’t disrupt your sleep. You might recall from part 2 that caffeine blocks the effects of adenosine, a chemical that builds up throughout the day and is responsible for the steady increase in ‘sleep pressure’ that occurs while we are awake. Caffeine usually has a half life of 4-6 hours, which means that 5 hours after a cup of coffee, half of its contained caffeine will still be in your system and interfering with your sleep pressure. For this reason, experts usually recommend avoiding caffeine within 6 hours of bed, but some people take longer to clear caffeine from their system than others, so keep that in mind.
You should also avoid nicotine and alcohol within around 4 hours of bed, though for different reasons. Like caffeine, nicotine is a stimulant – it activates the nervous system and raises alertness, which is the last thing you want while trying to fall asleep. Alcohol on the other hand is a depressant – it makes you feel more relaxed and can actually help you get to sleep. Unfortunately, alcohol also disrupts your sleep cycles and causes you to spend less time in the more restorative sleep phases, leading to poorer sleep quality overall.
Remember that the quality of your sleep is just as important as the quantity: even if the above drugs don’t seem to be stopping you from getting to sleep, that doesn’t mean they aren’t causing you problems. If you don’t feel refreshed when you wake up in the morning, it could be a sign that you need to cut down on the afternoon coffee.
Research suggests that exercise is a great at promoting sleep and improving sleep quality. This may be because exercise results in the production of more adenosine, and therefore greater sleep pressure. While exercise is generally good for sleep, it should be avoided within an hour or two of bedtime. That’s mainly because exercise raises your core body temperature, whereas sleep requires your core body temperature to drop by 1-2 °C.
If your only opportunity to exercise for the entire day is close to bedtime, there’s an argument to be made that the benefits of exercise outweigh the downsides. The evidence for the health benefits of exercise is very strong, whereas some recent studies suggest that moderate intensity exercise close to bedtime doesn’t really affect sleep that much if at all.
What is a chronotype, you ask? It’s a fancy scientific term for whether you are a morning person, evening person, or somewhere in between. Each person’s chronotype is largely determined by their genes, a handful of which have been identified. Most of them are ”clock genes” – the genes whose rhythmic activity is responsible for the rhythm of the brain’s master clock. A person’s chronotype determines when the upstroke and downstroke of their circadian rhythm will occur and, consequently, what time their alertness will peak. Most of us have a morning chronotype as children, swing dramatically towards an evening chronotype during adolescence, and then gradually drift back towards a morning chronotype as we age.
Most people will already have some idea of what their chronotype is, based on when they tend go to sleep and wake up when they have no commitments for an extended period. The easiest way to identify your chronotype is to take the MEQ (‘Morningness Eveningness Questionnaire’) test, a short questionnaire that will help you figure out exactly where you are on the spectrum. Commercial genetic testing can also tell you with pretty good accuracy what your chronotype is based on your clock genes.
So once you know your chronotype, what can you do with this knowledge? Well, the first thing this information allows you to do is to recognise whether you have been forced into a different activity schedule from that which your chronotype would favour. Do you arrive at work baggy-eyed and barely on time each day, wondering how your colleagues manage to go to the gym every morning and still reach the office before you? Unfortunately, most modern societies are not very accepting of evening chronotypes, but it can at least be helpful to know that it isn’t your fault (next time your boss chastises you for being late, you can indignantly show them your clock genes).
You may be able to mitigate some of the disadvantages of an extreme chronotype by making sure the sleep you do get is as high-quality as possible. Extreme chronotypes can also explain some sleeping problems that might otherwise be mistaken for insomnia. If you’re an extreme evening-type, but you need to go to bed at 9pm for a 5am start every morning, you are much more likely to encounter sleep problems. On a more positive note, knowing what time your alertness peaks can help you decide when you should undertake physically and cognitively demanding activities.
The first step towards sleeping properly is to wake up properly. As discussed in part 2, hormonal changes that occur upon waking set a timer that will determine when you start to feel sleepy later in the day. The best way to take advantage of this is to ensure you get as much light as possible in the morning, preferably sunlight. As a general rule, try to go outside and see at least 5 minutes of bright sunlight within an hour of waking up (without looking directly at the sun, of course). If the weather is bad, you might need to spend twice as long outside. Sitting next to a window, sitting in the front seat of a car, or turning on bright interior lights is better than nothing, but try to go outside if possible. Though it might not seem like it, outdoor sunlight is usually hundreds of times more intense than indoor light. The effects of light on the sleep wake cycle are much less powerful in the morning than they are later during the day, which means we need much more of it.
Another thing you can do to wake up more effectively is to raise your core body temperature in the morning. This could be achieved by setting your thermostat to raise your bedroom’s temperature by one or two degrees just before you usually wake up, drinking a warm drink after you wake, or taking a cold shower. A cold shower will reduce blood flow to your skin and extremities and stimulate the production of heat, raising your core body temperature. If you’re not too groggy, you could also begin the day with some exercise.
Even though caffeine can help you wake up, some experts advise avoiding it within an hour of waking. This is because its stimulant effects could interfere with the body’s natural cortisol spike in the morning, which could lead to you getting tired earlier in the day than you otherwise should (and then needing more caffeine later in the day, when it will be more detrimental to sleep).
We discussed in part 2 how entering the initial stages of sleep depends on the levels of certain hormones, core body temperature, and brain activity. The easiest way to disrupt hormonal sleep signals is through exposure to light, so avoid as much light as possible near bedtime. Most people know that blue light is bad, but ideally all light sources should be avoided. Once again, light has a much stronger effect on the sleep-wake cycle later during the day – even turning on your lights for a few moments can have a significant effect on your ability to sleep.
You may remember that your core body temperature needs to decrease slightly in order for you to sleep properly, so it’s important to ensure that your bedroom isn’t too hot – around 18-19°C is usually advised, though it may vary a little from person to person. It’s also helpful to raise the temperature of your skin and extremities prior to sleep, such as by taking a warm bath or shower, or placing a hot water bottle at the foot of your bed. As mentioned in part 2, this actually helps to decrease the core body temperature by diverting blood away from the core.
And there you have it – 15 relatively simple steps towards improving the quality and quantity of your sleep. If you find that you don’t currently follow most of these best practices for sleep, you certainly aren’t alone. We live in a sleep-deprived society, and fixing your sleep-wake cycle can seem daunting. Yet most of the suggestions here aren’t all that difficult to follow, and while some of them may feel like a sacrifice at first (such as forgoing coffee later in the day or taking the time to wake up correctly), you may find that increased alertness and energy during the day more than makes up for it.