Circadian Health Glossary
Ultradian Rhythm
The ultradian rhythm is one of the 4 biological rhythms. It dictates the pattern of our physiological and psychological functions on a short-term basis, within a single day. They are essential to different life processes and are particularly impactful during our sleep and waking hours.
The ultradian rhythm underpins our productivity and focus, with cycles lasting roughly 90 to 120 minutes, unlike the circadian rhythm which lasts 24 hours. During this time, our bodies shift through peaks of alertness and concentration followed by troughs of fatigue. Understanding and aligning with these natural waves can dramatically improve one’s time management and work output.
How Does the Ultradian Rhythm Work?
Sleep is a quintessential aspect of ultradian rhythm. Each night, we transition through various sleep stages in cycles of around 90 minutes, including periods of deep restorative sleep interrupted by lighter REM sleep phases. Awareness of this pattern can inform sleep schedules, potentially leading to more restful slumber and improved waking performance.
Ultradian Rhythm Examples
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Sleep cycles (90-120 minute stages)
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Blood pressure fluctuations
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Hormone secretion (e.g., growth hormone)
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Thermoregulation (body temperature control)
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Digestion
Potential Health Disruptions
Sleep Disruptions and Hormonal Imbalances
Consistent sleep disruptions or irregular work patterns such as shift work that ignore the body’s ultradian oscillations can lead to a host of health concerns. Some of them include metabolic issues, mood disorders, and even an increased risk of chronic conditions like heart disease.