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HOME / FASTING / ALTERNATE DAY
A 24 hour fast, then a normal eating day, repeating. Burn's first week runs four fasts with an eating day between each one.
It is a widely studied approach, and one of the most demanding patterns Burn runs, graded Experienced.
MON
24h
TUE
Rest
WED
24h
THU
Rest
FRI
24h
SAT
Rest
SUN
24h
Burn's Alternate Day program lays out both weeks day by day before you begin, so you can see the whole pattern before committing to it.
What a fasting day reaches
A 24 hour fast crosses the Fat Burning boundary right at its end, so each fasting day passes six of the nine stages. That is the appeal of the pattern: you reach a deeper stage repeatedly rather than once.
Some protocols allow a small meal on fasting days. Burn times a complete fast, so if you eat, end the fast and start a new one afterwards.
A rest day is a normal day of eating. Treating it as a reward for the day before is the most common way this schedule stops working.
Burn shows an electrolyte reminder as a fast passes 24 hours, and keeps sodium, potassium and magnesium in the Journal beside your water.
Who it suits
Some people find a daily eating window harder than a full day off food. If that describes you, this pattern suits how you think.
A GOOD FIT IF
A fasting day needs no decisions. An eating day needs no restraint. Some people find that easier than watching a clock every afternoon.
HARDER IF
Alternating days move through the week, so a fasting day will land on a dinner you cannot move. Burn's custom protocols let you set your own pattern instead.
NOT THE PLACE TO START
Burn grades this program as Experienced. Do a few single 24 hour fasts first, and build from a daily schedule rather than straight into this one.
Running it in Burn
Alternate Day is one of Burn's 21 programs. Both weeks are laid out day by day, so you can see which days are fasts and which are rest before committing to the pattern.
Burn labels every program Beginner, Intermediate or Experienced. This one sits at the top, alongside the longest protocols.
The program runs a fixed fourteen days. That gives the pattern a defined end, which is a useful thing to have when a schedule is this demanding.
A day counts once you finish its fast, so the figure on the program card records days completed rather than days elapsed.
Alternate day or 5:2
The difference is how many days, and whether your week keeps its shape.
Alternate day
Three or four fasting days a week, with an eating day between each one. Every fasting day reaches Fat Burning. Graded Experienced, and the demanding half of your week arrives every other day.
Choose it if you would rather have fewer decisions on more days.
5:2
Two fasting days a week, on days you pick and keep. Five days need no thought at all, and the pattern stays put week to week.
Choose it if your week has meals that cannot move.
BEFORE YOU START
Do not use this schedule if you are pregnant or breastfeeding, have a history of eating disorders, or are under 18. Speak to your doctor first if you manage diabetes or take medication timed to meals, since repeated full-day fasts affect how those doses land. Stop and eat if you feel unwell, whatever the timer says.
WHERE THE EVIDENCE STANDS
Alternate day fasting has been examined in controlled human trials, and produces weight loss comparable to other approaches at matched intake. Which pattern a person can sustain matters more than which is theoretically optimal. Claims here are drawn from peer-reviewed research and traced in our evidence policy.
Burn lays out every day before you start, names each stage as you reach it, and keeps the record afterwards.
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