Reset your body in 36 hours
Track your fasting journey through six metabolic stages. From fed state to autophagy, understand what's happening in your body every step of the way.
The Six Stages of Your 36-Hour Fast
Your body goes through remarkable metabolic changes during an extended fast. Here's what happens at each stage.
Fed State
0-4hYour body digests and absorbs nutrients from your last meal.
How you'll feel: Satisfied and energized
Early Fasting
4-8hBlood sugar levels begin to stabilize as digestion completes.
How you'll feel: Normal, slight hunger
Glycogen Depletion
8-12hYour body is using up stored glucose from your liver and muscles.
How you'll feel: Hunger peaks, then subsides
Fat Burning
12-18hYour body switches to burning fat for energy. Ketone production begins.
How you'll feel: Energy stabilizing
Deep Ketosis
18-24hFat burning accelerates. Your brain starts using ketones for fuel.
How you'll feel: Mental clarity improving
Autophagy
24-36hCellular cleanup and renewal. Your body is recycling damaged cells and proteins.
How you'll feel: Calm, clear, light
Everything you need to fast successfully
Simple, beautiful tools designed to guide you through your fasting journey.
Visual Progress Tracking
Beautiful circular timer shows exactly where you are in your fast with stage-specific colors.
Fasting Stage Insights
Understand what's happening in your body at each phase with detailed explanations.
Smart Scheduling
Set your weekly fasting schedule and get reminded when it's time to start.
Progress Notifications
Receive milestone updates as you progress through each fasting stage.
Fasting History
Track your completed fasts and see your progress over time.
Privacy First
All data stays on your device. No accounts, no servers, no tracking.
How Fast36 works
Getting started is simple. Three steps to transform your health.
Schedule
Set your weekly fasting day and preferred start time. The app will remind you when it's time.
Track
Watch your progress through each metabolic stage with real-time visual feedback.
Complete
Celebrate reaching the 36-hour mark and experiencing the benefits of autophagy.
Why practice 36-hour fasting?
Extended fasting triggers powerful metabolic and cellular processes that shorter fasts can't achieve. Here's what you unlock after 36 hours.
Enhanced Fat Burning
Extended fasting depletes glycogen stores, pushing your body to burn fat for fuel.
Cellular Autophagy
Your body activates powerful cellular cleanup and repair mechanisms after 24 hours.
Mental Clarity
Ketones provide clean, efficient fuel for your brain, improving focus and clarity.
Metabolic Reset
Give your digestive system a complete rest and improve insulin sensitivity.
Ready to start your fasting journey?
Download Fast36 and experience the benefits of extended fasting with beautiful progress tracking.
Download for iOS — It's FreeNo account required. Your data stays on your device.