What Is Your Sleep Chronotype, and Why Does It Matter?

By Melissa Blake, ND

When was the last time you jumped out of bed feeling refreshed? How often do you look in the mirror and see someone who is ready to take on the day?

Good-quality sleep is essential to good health. Without it, we are more likely to feel tired, worn out, and wanting to go back to bed. Not enough good-quality sleep can also contribute to more serious health concerns, including weight gain and cardiovascular issues.¹ In fact, several cohort studies suggest that people who consistently sleep six hours or less per night are almost twice as likely to be overweight than those who slept seven hours or more each night.²

If sleep is so important, why do so many of us struggle to achieve it?

Body rhythms & sleep chronotypes

There are four basic sleep chronotypes: early bird (or lark), morning person, intermediate sleeper, and night owl.⁵ Your chronotype has a huge impact on your daily patterns: how alert you feel during the day, how often you fall asleep on movie night, whether you consider yourself part of the 5 AM club, and even how well you perform at work!

Larks are early risers, perform mentally and physically at their best in the morning hours, and go to bed early in the evening. Owls stay up late at night, rise later in the morning, and perform best mentally and physically in the late afternoon or evening.⁵ These two preferences are assumed to have special biological, genetic, psychosocial, and contextual components.⁶

The most significant environmental influence on sleep/wake rhythms is the solar clock, which provides exposure to heat and light.⁵ Genetic variations in your internal biological clock determine your chronotype. The more responsive you are to these signals, the more likely you will identify as a morning person. Your chronotype is further influenced by a social clock, including exposure to artificial light, shift work, nightcaps, and exercise habits.⁵

You can’t change what you don’t track

The best way to determine your chronotype is by tracking your patterns and identifying trends. The more you know about how your body responds and what it likes, the more insight you’ll have into what you can do to improve your health when it gets off track. Data doesn’t lie. Once you’ve identified patterns, you can adjust your habits.

There are many wearables and apps that can support sleep tracking. You can also use a sleep journal. The following table provides an example of how you can capture insights into your sleep patterns.

After two weeks have passed, look at the data to see if there are any patterns that emerge. If not, track a little longer until they do. What do you notice? Is your bedtime consistent? Does alcohol, exercise, or caffeine influence how quickly you fall asleep or how rested you feel the next day? What changes can you make, even with just shifts of 15 or 30 minutes, to optimize your unique sleep style?

Circadian disruption

Circadian disruption, also known as social jetlag, occurs when a person’s natural sleep tendencies (chronotype) are not in line with his or her lifestyle. Work responsibilities, light exposure at night, shift work, “all-nighters,” routines that change on weekends, caffeine intake, intense exercise, and time zone all influence sleep cycles and can contribute to a disruption in natural rhythm.⁷

The ideal situation is when we can align all three clocks in our favor: solar, biological, and social.⁵ If you notice that you consistently hit the snooze button, consider shifting your day by 15-30 minutes to give your body that bit of extra time in the morning. If you consistently feel your best in the early-morning hours, aim to schedule your heaviest work before noon and avoid evening meetings when possible. Slight adjustments in your schedule can lead to big payoffs. The same goes for what we do in the few hours before sleep. Some people may get a burst of energy shortly after exercise and may want to schedule their activity for several hours before bed. If you often spend more than 30 minutes lying awake at night before falling asleep, you may want to delay your sleep time to 30 minutes later, so you are more likely to catch your sleep wave.

Of course, your sleep chronotype isn’t a fixed characteristic—it can change over time as a result of things like age, stress, and time zones.⁵ Even a 30-minute shift in sleep and wake times can make a difference one way or the other. That’s why it’s important to pay attention to how your body responds to different approaches to sleep.

A personalized approach to optimal sleep

Sleep is an important part of our overall health and wellness, so it’s important to understand our own patterns and habits so that we can adjust accordingly. There are still many unanswered questions about chronotypes and the health implications of different types, but one thing is clear: We don’t all operate on the same schedule. These differences are not just a matter of preference or social conditioning—they may be written into our DNA. If you want to be your best self, whether at work or in relationships with family members, then knowing more about how your body works will help you meet its needs more effectively. Track your habits, identify trends, and make positive steps toward better health, including consistently restorative sleep.

For more information on sleep and general wellness topics, please visit the Metagenics blog.

References

1. McMahon DM et al. Relationships between chronotype, social jetlag, sleep, obesity and blood pressure in healthy young adults. Chronobiol Int. 2019;36(4):493-509.
2. Antza C et al. The links between sleep duration, obesity and type 2 diabetes mellitus. J Endocrinol. 2021;252(2):125-141.
3. Montaruli A et al. Biological rhythm and chronotype: new perspectives in health. Biomolecules. 2021;11(4):487.
4. Fárková E et al. Comparison of Munich Chronotype Questionnaire (MCTQ) and Morningness-Eveningness Questionnaire (MEQ) Czech version. Chronobiol Int. 2020;37(11):1591-1598.
5. Roenneberg T et al. Life between clocks: daily temporal patterns of human chronotypes. J Biol Rhythms. 2003;18(1):80-90.
6. Urbán R et al. Morningness-eveningness, chronotypes and health-impairing behaviors in adolescents. Chronobiol Int. 2011;28(3):238-247.
7. Taillard J et al. Sleep timing, chronotype and social jetlag: Impact on cognitive abilities and psychiatric disorders. Biochem Pharmacol. 2021;191:114438.

Melissa Blake, ND Melissa Blake, ND obtained her naturopathic medical training from the Canadian College of Naturopathic Medicine in Toronto. Dr. Blake has over 10 years of clinical experience. She takes a personalized approach in her clinical care that involves finding the root cause of disease with a strong emphasis on mindfulness and research-based natural therapies. In 2019, she transitioned to a part-time, virtual practice, a change that accelerated her interest in the impact of digital technologies in healthcare. In her current role at Metagenics as a Product Manager, Dr. Blake works with an amazing team of talented individuals, creating digital solutions that increase access and support adherence so that both patient and practitioner achieve the best possible results. In her spare time, she enjoys having fun with her family, being in nature, playing piano, and studying for a master’s degree in counselling psychology.