90 Minute Timer
READY
90:00
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Common uses for a 90 minute timer
- Ultradian deep work blocks
- Long exam sections
- Extended creative sessions
- Workshop and seminar slots
- Yoga and movement sessions
- Long cooking processes
Neuroscientist Andrew Huberman popularised 90-minute work blocks aligned to the ultradian rhythm. After a 90-minute block, the brain naturally enters a lower-alertness phase — an ideal time for a non-sleep deep rest (NSDR) or walk.
90 minutes aligns with the human ultradian rhythm — the natural cycle of alertness and rest the brain cycles through every 90 minutes. Working with this cycle rather than against it maximises sustained cognitive output.
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❓ Frequently Asked Questions
What is the ultradian rhythm?
The ultradian rhythm is a 90-minute cycle of high and low neurological alertness that repeats throughout the day. Working in 90-minute blocks with intentional breaks aligns effort with natural brain states.
Is 90 minutes too long to focus?
For most people, 90 minutes is the upper limit of sustained peak focus. The key is entering the block with clear intent and eliminating distractions completely — not gradually working up to focus during the block.