Sleep Timing by Chronotype
Michael Breus, PhD, ABSM ('The Sleep Doctor'), a board-certified sleep-medicine clinical psychologist, teaches that individual circadian phase varies meaningfully between people and matters for when you seek light, cut off caffeine, and go to bed. His popular lion/bear/wolf/dolphin chronotype framework is his own simplification of real chronobiology, not itself a peer-reviewed instrument, and is labeled as such here. Disclosed commercial interest: he sells his own branded sleep products and a paid chronotype quiz; this page is graded against the published chronobiology, not his commercial offerings.
Notice when you naturally wake without an alarm and when you naturally feel alert versus sluggish, to place yourself roughly as an early type, a standard type, or a late type n/a, self-observation
This is the real, underlying chronobiology variable Breus's framework is built on: individual circadian phase differs and shifts what timing works.
Seek bright light (outdoor light or a light-therapy lamp) within the first hour or two of your natural wake time, not a fixed clock time 10-30 minutes, timed to your own wake time
Morning light exposure is a well-established way to anchor circadian phase, and timing it to your own wake time (not everyone else's) is the chronotype-specific adjustment.
Stop caffeine earlier in the day if you are an earlier chronotype, since your circadian wind-down starts sooner than a standard schedule assumes Individualized, commonly 8-10 hours before your own natural bedtime
Caffeine's half-life is fixed, but your bedtime is not, so the effective cutoff shifts with your chronotype.
Use lion/bear/wolf/dolphin as a memorable label for your general pattern, not a clinical instrument n/a
The 4-type packaging is Breus's own simplification of real chronobiology for a general audience; it is a helpful label, not a peer-reviewed diagnostic tool.
Circadian phase (when your internal clock is naturally aligned to sleep, wake, and alertness) varies between individuals based on genetics and age.
View sources
Dr. Michael Breus, The Sleep Doctor
Not medical advice. This page is for education only and is not a substitute for professional medical care. Consult a qualified clinician before changing your health routine.
Independent curation. YourProtocol is an independent platform. This protocol is based on the publicly available work of Michael Breus, PhD, ABSM and is not created, reviewed, endorsed by, or affiliated with Michael Breus, PhD, ABSM or Independent practice, former WebMD Sleep Expert.
Is this for you
- Anyone whose sleep advice never seems to fit their actual schedule
- People who want their circadian phase, not a generic 10pm bedtime, driving their sleep timing
Cautions
- The lion/bear/wolf/dolphin framework is a popularized label, not a peer-reviewed diagnostic instrument
- Disclosed COI: Breus sells branded sleep products and a paid chronotype quiz; this page is graded against the published chronobiology, not his commercial offerings
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