The 90 Minute Ultradian Rhythm: A Framework for Peak Focus
Your brain can only focus for 90 minutes before it needs to rest. Here is how to map your work sprints.
We often talk about the circadian rhythm, which governs our 24 hour day. However, our bodies also operate on shorter cycles called "ultradian rhythms." These cycles govern our focus, energy, and alertness in blocks of approximately 90 minutes.
The Limits of Human Focus
Neurobiological research has shown that the human brain cannot maintain intense, focused states for longer than an hour and a half without a significant drop in performance. Pushing past this window leads to cognitive fatigue, increased errors, and a buildup of stress hormones.
How to Structure Your Sprints
To maximize your output without burning out, you must align your work with these natural biological waves.
ARC helps you identify when these 90 minute windows naturally occur based on your daily energy curve.
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