Cognitive Scaffold

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MENTAL MODEL · M1686

Ultradian Rhythm

Ultradian Rhythm
TechnicalHigh supportPhysics
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Version 1.0.0 · Updated 2026-07-30

CORE DEFINITION

In addition to the 24-hour circadian rhythm, the human body also has shorter 90-120 minute activity-rest cycles (BRAC). After 90 minutes of high-intensity activity, the body sends fatigue signals (mind wandering, yawning).

SCAFFOLDING EFFECT

psychology

Reduce cognitive load

- The science of rest: a physiological enhancement of the Pomodoro Technique (25 minutes). Every 90 minutes of work, you must physically disconnect (walk around, look into the distance) for 15 minutes. Fighting this rhythm with coffee will only lead to a cortisol spike and a collapse in efficiency.

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Ultradian rhythms refer to physiological or behavioral rhythms with a period shorter than a day, such as the 90-120 minute sleep cycles. They are distinct from circadian rhythms.

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Source support: Explicit

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    en.wikipedia.orghttps://en.wikipedia.org/wiki/Ultradian_rhythmZH · Explicit
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