Circadian Health Glossary
Phase Shift
A phase shift refers to a change in the timing of the body’s circadian rhythms, such as the sleep-wake cycle, relative to the 24-hour day. Phase shifts can move the rhythm earlier (phase advance) or later (phase delay), depending on external factors like light exposure or lifestyle changes.
What Causes a Phase Shift?
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Light Exposure: Bright light in the morning causes a phase advance, while exposure in the evening leads to a phase delay.
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Melatonin: Supplementation can shift the circadian clock depending on the timing of administration.
- Jet Lag and Shift Work:Traveling across time zones or irregular work schedules can induce phase shifts.
Why Are Phase Shifts Important?
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Circadian Disorders: Misaligned phase shifts contribute to conditions like Delayed Sleep Phase Disorder (DSPD) or jet lag.
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Light Therapy: Phase shifts are intentionally induced using light therapy to treat circadian rhythm disruptions.
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Health and Performance: Aligning phase shifts with the body’s natural rhythms improves sleep, alertness, and overall well-being.
Understanding phase shifts is essential for managing circadian health and adapting to environmental or lifestyle changes.