Burn
Get Burn
Burn
Get Burn
HOME / FASTING
A fasting schedule is just two numbers: hours you don't eat, hours you do. Or no numbers at all, if you'd rather run open-ended and stop when it feels right. Every way Burn runs a fast, what each one asks of you, and where to begin.
A 16:8 you keep beats a 20:4 you abandon on day three. Burn lets you move up when the shorter fast stops feeling hard.
Your plan is a setting, not a commitment. Burn shows your current plan at the top of the list, and you can pick a different one whenever the week calls for it.
Start open-ended and the timer just counts, naming stages as you pass them. No target, nothing to fail. Three custom protocols too, if you'd rather define your own window.
Daily schedules
Same timer, three different windows. The longer you go, the further into the stages you get, and the more the plan asks of your evenings.
Dinner at eight, lunch at noon. You sleep through most of it, and you reach Fat Mobilisation by morning.
Deepest stage reached: Fat Mobilisation
Read the 16:8 guide →
Two hours further than 16:8, which is where ketone production starts to mean something.
Deepest stage reached: Ketosis Entry
Read the 18:6 guide →
One four-hour window. Harder socially than physically once you're used to it.
Deepest stage reached: Ketosis Entry
Read the 20:4 guide →
Same body, same path
Your schedule decides how far along this ladder you get, and an open-ended fast simply keeps going up it. Either way the ladder itself doesn't change. Burn names the stage you're in, tells you what's happening, and says how firm the evidence behind it is.
Guided programs
Tell Burn the goal and it writes the week for you, a target per day, getting harder only when you're ready for it.
A week that walks you from a twelve-hour fast to a sixteen, so the first hard morning isn't day one.
Three weeks of climbing targets, with easier days built in so the week stays survivable.
Four weeks from sixteen hours up to eighteen, for people who already fast and want a structure.
Three custom protocols, any fasting and eating window you like, saved and reusable. Night shifts, race weeks, Ramadan, whatever your calendar actually looks like.
How custom protocols work →
Fasting without food
Past a daily window the question changes from when you eat to what you take while you don't. Two practices, each with its own section.
WATER, SALT, COFFEE, TEA
From one day to a full week, with fluid and electrolytes available throughout. How to run one, the safety threshold at each length, and how to break it.
Read the water fasting guides →
NO FOOD, NO WATER
The practice with fluid withheld, from the daylight-hours pattern upward. What it involves, what dehydration affects, and where the research stands.
Read the dry fasting guides →
Every schedule, in one place
Each one has its own guide: how it runs, who it suits, what a normal day looks like on it, and how far into the stages it takes you.
The ones you repeat every day.
Fasting some days, eating normally on others.
Head to head, so you can pick once and get on with it.
SCHEDULES · 5 MIN
What actually changes as the window narrows, and what doesn't.
HUNGER · 4 MIN
Hunger arrives in waves on your old meal schedule, and waves pass.
RULES · 3 MIN
Black coffee, tea, sparkling water, and the things people get wrong.
GETTING STARTED · 6 MIN
Day by day, including the two days that take the most planning.
Or start open-ended and decide in the morning. You can change your mind tomorrow either way, and the app keeps the history. Finish dinner, hit start, go to bed.
Download free on the App StoreiPhone, iPad, and Apple Watch. Requires iOS 18 or watchOS 11.