Ultradian rhythms are the natural cycles — commonly cited as around 90 minutes — in which your alertness and energy rise and then dip throughout the day. They are one reason focus feels effortless at some points and impossible at others.
Why it matters
Fighting a downswing with more coffee and willpower rarely works well. Aligning demanding work with your natural peaks, and resting on the troughs, tends to produce more with less strain.
How to apply it
- Work in focused blocks of up to ~90 minutes, then take a real break.
- Notice your daily peaks and guard them for your hardest tasks.
- Use downswings for shallow work, admin, or genuine rest.
- Don't push through a deep trough — a short reset restores more than grinding.