Fasting Timer
Ready to Fast
00:00:00
Goal: 16h (16:8 IF)
Hydration, Electrolytes & Weight
Water Intake: 0 ml
Goal: 2,500–3,500 ml during water fasts
Sodium: 0 mg
Prevents fasting headaches & fatigue (3,000–5,000 mg/day on water fasts)
Potassium: 0 mg
Muscle & heart rhythm support (2,000–3,000 mg/day on water fasts)
Magnesium: 0 mg
Sleep & cramp prevention (300–400 mg/day)
Daily Weight (kg)
Log weight to track trend
Metabolic Fasting Stages
Start a fast to track stages
0 – 4h
Anabolic / Digestion
Blood sugar and insulin are elevated while your body processes your last meal.
4 – 12h
Catabolic / Post-Absorptive
Insulin drops; your body uses stored liver glycogen for energy.
12 – 16h
Fat Burning & Early Ketosis
Glycogen depletes; lipolysis accelerates and ketone production begins.
16 – 24h
Autophagy & HGH Surge
Cellular cleanup (autophagy) activates and human growth hormone rises to preserve muscle.
24 – 48h
Deep Ketosis & Cellular Repair
Brain runs heavily on ketones (BDNF rises); inflammation markers drop significantly.
48 – 72h+
Peak Autophagy & Stem Cell Renewal
Deep water-fasting zone: old immune cells recycle and stem cell regeneration increases.