36-Hour Fast (Monk Fast) Schedule: Plan, Milestones, How to Break
The 36-hour fast — sometimes called the Monk Fast — pushes you firmly into deep ketosis and full autophagy. It's a single overnight fast extended through one full day plus a second night. Done weekly or biweekly, it captures most of the metabolic benefit of longer fasts at a fraction of the difficulty.
How 36-Hour Fast works
Eat dinner Day 1 around 19:00. Skip all meals on Day 2. Don't eat until breakfast on Day 3 around 07:00. Water, electrolytes, black coffee, and tea throughout. Plan a light Day 2 — walks, gentle yoga, easy work — and an early bedtime.
A sample day
- Day 1, 19:00Last meal — substantial, balanced, low-sugar.
- Day 2, 07:00Water + 1/2 tsp sea salt + black coffee.
- Day 2, 12:00Magnesium 200 mg + potassium 400 mg.
- Day 2, 16:00Walk. Water. Mental clarity peaks.
- Day 2, 21:00Salt water + magnesium. Sleep.
- Day 3, 07:00Break fast with broth, then a small balanced meal.
What happens in your body
Physiological milestones reached during a 36-hour fast.
- h4
Blood sugar normalizes
Insulin drops back to baseline as your last meal finishes digesting.
- h8
Glycogen burning begins
Your liver starts releasing stored glycogen to keep blood glucose steady.
- h12
Glycogen depletion
Liver glycogen runs low; the body shifts toward fat for fuel.
- h14
Fat burning accelerates
Lipolysis ramps up — stored triglycerides break down into free fatty acids.
- h16
Mild ketosis starts
The liver begins producing ketones from fatty acids. Mental clarity often improves here.
- h18
Growth hormone rises
HGH increases up to 5×, supporting muscle preservation and tissue repair.
- h24
Autophagy begins
Cells start digesting damaged proteins and organelles — the housekeeping phase.
- h36
Deep ketosis
Beta-hydroxybutyrate climbs; the brain runs primarily on ketones.
What to eat
Refeed carefully. Start with 200–300 ml bone broth or vegetable soup, wait 30 minutes, then a small meal of cooked vegetables and lean protein. Avoid heavy fat, raw vegetables, and dense carbs in the first refeed. Resume normal eating by lunch.
How to break the fast
- Bone broth, then scrambled eggs and steamed spinach
- Vegetable soup, then chicken breast with cooked carrots
- Plain yogurt with stewed apple and a small amount of granola
- Dal, white rice, and steamed greens
Who it's for
- • People comfortable with 24-hour fasts
- • Those targeting autophagy without committing to 72+ hours
- • Biohackers who want a measurable cycle every 1–2 weeks
Benefits
- • Deeper ketosis than 24-hour fasts (β-hydroxybutyrate >1 mmol/L common)
- • Autophagy clearly active by hour 30
- • Clear improvements in fasting glucose and triglycerides over 8 weeks
Risks & cautions
- • Pronounced electrolyte needs — sodium, potassium, magnesium daily
- • Light-headedness and cold extremities common in hours 24–36
- • Sleep on night 2 may be lighter than usual
- • Not appropriate for diabetes, eating-disorder history, or pregnancy
Frequently asked questions
Is a 36-hour fast safe?
How often can I do a 36-hour fast?
Will I lose muscle on a 36-hour fast?
Can I exercise during a 36-hour fast?
Related schedules
Track your 36-Hour Fast fast in QoFast
Live timer, milestone tracking, water and electrolyte logging — free on iOS & Android.
