Some people naturally wake with the sun, while others come alive at night. Sleep experts explain what your chronotype reveals about your body clock – and whether you can change it.
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When it comes to sleeping well, there are two main lines of thinking: listen to your body, or listen to the sun (aiming for eight hours either way, sure). Knowing which line of thinking is correct has more nuance than you might think. Of course, many of us wake up and sleep in line with our obligations such as work and getting the children to school; others of us believe that we perform better if we get up at 4:30am. Neither is necessarily what we, physiologically, should be doing though it can be.
Understanding your chronotype
According to Sleep Foundation, “Chronotypes are natural preferences of the body for wakefulness and sleep”, driven by genetics and our own circadian rhythm. This extends to when we sleep, but also to when we are most alert, most able to focus, and when we would prefer to be doing low-energy activities.
The reason it is useful to know what our chronotype is that adapting to our natural needs is useful for optimising sleep quality, which in turn will optimise our energy and mood regulation. However, Sleep Expert and Psychiatric-Mental Health Nurse Practitioner Dr. Lori Bohn says, “chronotypes don’t have to be seen as a set of predetermined labels that dictate how we live”. They also can change during our lifetime, particularly in adolescence and in older adulthood, according to Age UK.
What are the chronotypes?
There are four main chronotypes, but within them there is variation (they’re a loose set of categories and our very specific individual make-up falls into one of them). Most people use an animal-theme coined by Dr. Michael Breus to remember the categories.
Bear chronotypes represent most people (55-60%) and tend to be the type of person that most closely follows the sun (as well as a standard 9-5 schedule), waking up a 7am and sleeping for around 11pm. Lions are the early risers, who wake up before 6am and sleep for around 10pm.
Wolves tend to be people who find they are more alert as the day goes on – naturally getting out of bed at 8am or later, but not sleeping until gone midnight, with their energy peaking in late afternoon. Dolphins are the rarest chronotype, and tend to be those with insomniac traits. They tend to do best waking up around 6:30am (though they’ll feel like sleeping in for much longer), they’ll have a busy mind through the day, and not manage to wind down until after 11:30pm.
There are more nuances within each of these, such as optimal times for eating, whether or not to nap, and where focus levels hit a peak. Seeing which is closest to your natural rhythm, or even letting yourself follow a schedule to see if it seems to work can be life-changing.
Chronotypes are not the same as circadian rhythms
Dr Bohn says that one of the largest myths she hears is that chronotype and circadian rhythm are interchangeable terms. They’re not. “A chronotype describes a person’s preferred timing based upon their circadian rhythm, whereas the circadian rhythm itself represents the internal 24-hour physiological clock that controls the timing of all biological processes.”
Essentially, while everyone has a circadian rhythm which does a certain set of things in a day (a slee-wake cycle, for example), individual differences and preferences exist (the time of day you optimally should sleep) which is a sign of your chronotype. One is a set of natural rhythms, the other is an internal body-clock (though confusingly, the latter isn’t the one that has “chrono” in the name).
Therefore, Dr Bohn says “working with your chronotype can boost the impact of your circadian rhythm.” Adding that “as the circadian system reacts very well to consistency, finding a daily routine that you can sustain is significant for healthy functioning.”
How to get the sleep routine you want even
Annoyingly, life tends to get in the way of a chronotype. Night shifts, screaming young babies, aches that keep us up, mental health issues, simply being a night owl (wolf) in a 9-5 (bear) world. As a result, we have to prioritise, and “consistent sleep periods are usually more important than establishing sleep periods that fit a chronotype.” Dr Bohn says.
Sleep deprivation has a direct link to all-cause mortality rates, as reported in Nature. It is important we try to sleep, even if it is sometimes difficult. Dr Bohn says that as an example “chronic sleep deprivation occurs when a person accepts their preference for late nights and fails to modify their habits appropriately.”
Essentially, good sleep hygiene can help to manipulate our chronotypes into following the routine we would prefer to have. It might be tricky, might have to allow for your specifics in some areas (a midday nap, eating at certain times) but a compromise between your chronotype and circadian rhythm can be found to let you sleep during the hours you want.
When there’s more of a sleep issue than a chronotype clash
“Additionally, I want to emphasise that sleep or tiredness issue can be attributed to chronotype.” Dr Bohn says, adding that “long-term fatigue, heavy snoring, restlessness during sleep, or excessive daytime drowsiness could represent sleep disorders or another conditions that need medical advice.”
You can’t blame your chronotype for poor sleep quality, sadly. Or at least, doing so will not solve the problem. Altering the time you sleep, and generally improving sleep hygiene can help, but in some cases other issues mean seeking out a GP’s take. We are all individuals, and we must do the things that work for us.
That being said, some people do actually benefit from being up at weird and wonderful times of the day. This can be because it allows people to tailor their routine to the life they want to live, stay away from temptations, or simply get rid of the noise that distracts them from their goals.
But if you find you are constantly sleeping poorly, and it isn’t a medical, hormomal, or psychological issue, considering what your chronotype wants might be helpful. Dr Bohn says to “see chronotypes as a tool for helping understanding yourself — not a guide that tells you exactly how to behave.” Sleep on that.
