Ultradian Rhythms 90/20

Focus Medium 14 days ourarescuetime
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Start the Health OS protocol "Ultradian Rhythms 90/20" (focus-pomodoro-50-10) and show me today's step.

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Goal

Test how working in 90/20 blocks affects deep work and fatigue

Hypothesis

Working in 90 min blocks with 20 min breaks → more deep work → less fatigue

~90-minute ultradian rhythms drive concentration cycles. Working in sync with these rhythms boosts productivity (Peretz Lavie, Rossi)

Expected Effects

  • ↑ deep_work_hours
  • ↓ end_of_day_fatigue

Phases

1

Baseline

7 days
  • Work as usual
  • In the evening, log deep work hours and fatigue
2

90/20 Blocks

7 days
  • Work in blocks: 90 min focus → 20 min break
  • During the break: walk, stretch, NO screens
  • Target: 3-4 blocks per day
  • In the evening, log deep work hours and fatigue

Tracked Metrics

Primary

  • ↑ deep_work_hours

Secondary

  • ↓ end_of_day_fatigue

Evaluation

Method: compare_phase_means

Design: baseline (7 days) → intervention (7 days)

Safety

Disclaimers

  • Don't skip breaks — they're critical to the protocol
  • If severely fatigued — shorten blocks to 60 min

Stop Conditions

  • Chronic headaches
  • Burnout or inability to focus even at the start of a block