The reality of sleep needs
When I work with people with insomnia, one sleep goal I repeatedly hear from my patients is “I want to get 8 hours of sleep” or “if I could just get 8 hours of sleep, I would be so happy”. This is not surprising at all because many people have a very entrenched belief that eight hours is how much sleep humans need to optimize their sleep and health. This belief is the root of a significant amount of sleep anxiety when people find that they do not appear to be sleeping eight hours a night.
What if I told you that the eight-hour average is just that – an average. And like any other average, there is a normal distribution around it that people can fall. Some people are five or six-hour sleepers; others are nine or even ten-hour sleepers. Our individual sleep needs are completely unique to ourselves. This is also true for our chronotype (i.e., the time that our body feels the best). Some people are early and others are night owls – most fall somewhere in between. But how does the eight-hour belief lead to insomnia?
A Tale of Shoes and Sleep
Imagine you are wanting to buy some new shoes. At the store, there’s one particular sleek pair of sneakers that attracts your gaze. However, there’s a bit of a problem: the sneakers you wanted only come in size 8’s but you are a size 6. You decide to buy them anyways, thinking it wouldn’t be that big of a deal. However, throughout the day you realize that the mismatch in your feet and the shoes is creating more trouble than you thought. Your feet are jostling around in your shoes; the shoes are constantly slipping off your feet; and you are all around in much pain and discomfort. At this point, you’re probably wondering to yourself: “why is this guy talking about shoes in a post about sleep?”.
Bringing it back to insomnia
We as clinicians love our analogies. And the shoe size analogy is a good one for what happens when someone who is a 5 or 6 hour sleeper believes that they need eight hours of sleep. Their sleep naturally becomes very uncomfortable because the fit between their sleep needs and how much time they are spending in bed doesn’t mesh well. Another analogy that I like to use is the ‘pizza dough’ analogy. If you had a 9-inch pan but only 6 inches worth of dough, what would happen if you tried to spread that dough into the pan? In this case, the dough would be too thin, and holes would start to open up in the dough. This is the same in sleep. If you try to stretch a 6-hour sleep need into an 8- or 9-hour bedtime window, you are going to experience a lot of awakenings and the sleep is going to feel very light. Sounds familiar, right? These symptoms are exactly what insomnia is all about. The additional time spent in bed can also reduce sleep drive and lead to conditioned arousal. To learn more about these ideas, see this post on causes of insomnia!
How do I figure out my unique sleep need?
Having a sleep window that is closer to your sleep needs is important in reducing wakefulness in bed and increase your drive for sleep. It is therefore important to learn more about your own unique sleep need. To find out, Dr. Colleen Carney, a leading expert in behavioural sleep medicine developed a sleep diary that allows you to calculate how much sleep you are producing relative to how much time you are spending in bed. The sleep diary is a simple tool that helps to track your sleep patterns through the night. The instructions are simple: after you wake up in the morning, you fill in the information about how the last night’s sleep was (for example, when you got into bed and how long it took you to fall asleep). This is based on your own subjective guess, so don’t feel like you need to watch the clock! Your best guess is the best answer. Usually, to get a stable picture of your sleep, you need to complete 2 weeks of sleep diaries.
Here is the website: https://consensussleepdiary.com/
If you’re interested in learning more about your chronotype, check out this website: https://chronotype-self-test.info/index.php?sid=61524&newtest=Y
I hope this was helpful in some good ol’ fashioned myth busting about sleep and insomnia! Let me know what you think your sleep size is in the comments!