Circadian Rhythm & Sleep Health Tips
What are Melatonin and the Circadian Rhythm?
The production of melatonin, often referred to as our sleep hormone, increases with evening darkness and is a central part of our body's sleep-wake cycles. The circadian period of sleep/wake is around 24.2 hours, and there are many endogenous and exogenous factors that can shift a circadian rhythm. Cortisol and melatonin are inversely related; cortisol peaks highest in the morning and melatonin is highest in the evening.
Reasons You Can’t Fall Asleep:
- Anxiety/stress
- Low melatonin levels
- Excess light/electronic stimulation
- Hormonal imbalances
- Medication/caffeine stimulation
- Neurotransmitter imbalances
Reasons You Can’t Stay Asleep:
- Cortisol (stress hormone) spiking in the middle of the night — you might feel ‘wired but tired’
- Dysregulation of body temperature due to hormonal imbalances
- Blood sugar fluctuations
- Low oxygen levels
- Liver health issues
Sleep Hygiene Tips:
- Keep regular bedtimes and wake times, even on weekends to train your biological clock.
- Avoid alcohol within 3 hours of bedtime.
- Avoid caffeine after 2 pm. Some individuals may be more sensitive — limit caffeine intake before noon. This includes beverages, chocolate, etc.
- Complete aerobic or high-intensity interval training before 6 pm.
- Use the bedroom only for sleep and sex — not for watching TV or eating.
- Avoid watching stressful or negative content before bed.
- Journal your thoughts prior to bedtime.
- Aim for consistent bedtime between 10–11 pm; this is associated with a decreased risk of developing heart disease.
- Incorporate breathing exercises, calming sounds, or meditation before bed. Apps like Calm, Headspace, and Insight Timer can help.
- Consider Epsom salt baths to reduce muscle tension and promote relaxation.
- Avoid large meals and finish eating at least 3 hours before bed.
- Get regular outdoor light exposure — watch the sunrise and sunset to regulate circadian rhythm.
- Avoid sleeping near electromagnetic fields (EMFs) — including electrical outlets, phones, and electronics.
- Maintain a comfortable room temperature — ideally around 65°F to promote REM sleep.
- Avoid blue light before bed — turn down screen brightness, use apps like f.lux, or wear blue light glasses.
Citations:
- Arendt J, Skene DJ. Melatonin as a chronobiotic. Sleep Med Rev. 2005;9:25-39.
- Monk TH. Enhancing circadian zeitgebers. Sleep. 2010;33(4):421-422. doi:10.1093/sleep/33.4.421
- Okamoto-Mizuno K, Mizuno K. Effects of thermal environment on sleep and circadian rhythm. J Physiol Anthropol. 2012;31(1):14. doi:10.1186/1880-6805-31-14
- Oster H, et al. The Functional and Clinical Significance of the 24-Hour Rhythm of Circulating Glucocorticoids. Endocr Rev. 2017;38:3–45.
- Nikbakhtian S, et al. Accelerometer-derived sleep onset timing and cardiovascular disease incidence: a UK Biobank cohort study. Eur Heart J - Digital Health. 2021;2(4):658–666. https://doi.org/10.1093/ehjdh/ztab088
- Zisapel N. New perspectives on the role of melatonin in human sleep, circadian rhythms and their regulation. Br J Pharmacol. 2018;175(16):3190-3199. doi:10.1111/bph.14116
Disclaimer: This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified healthcare provider with any questions regarding a medical condition or treatment. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.