Jump to content

Fasting and Fainting

Thomas G

Recommended Posts

In 2017 I've decided to try to do quarterly five day water-only fasts. I did my first one on Jan 2-6. Because of some upcoming travel in April I'm doing my second one now. I'm on the last day of a five day water-only fast. I usually take my blood pressure every day. For the first three days of this fast my blood pressure was pretty normal for me lately, about 120ish over 70ish. But yesterday my blood pressure was 100/65. I thought the reading might be a fluke so I took it a few more times and got the same result. Even later in the day it was still in that same range.


Yesterday I felt dizzy when I stand up too quickly, but I've took things slowly during the day. Last night I couldn't sleep. I felt wide awake, restless, and my back hurt. At around 2:30 a.m. I got up to use the bathroom. I don't remember falling but the next thing I knew I was on the floor holding my hip and in a little pain. I fainted and hit my stomach on the corner of a table and the top of a chair, and my hip has a nice bruise. My chin and jaw hurt a little too (I must have hit my chin on the floor).


I've never fainted before and I'm concerned. My wife quickly googled fasting and fainting and found info on dehydration. During my fast in Jan. I was trying to drink as much water as Cron-o-meter says I should. I think that was a mistake. I had to drink an abnormally large amount of water. I guess that is because I'm not getting any water from the foods I normally eat. But the last two days of the fast in Jan. I felt very odd, and basically treated them as sick days. I would have broken the fast if I felt that way early on, but since I was so close to being finished I just stuck it out in bed. Looking up info online I saw stuff about drinking too much water on a fast diluting electrolytes. I don't know much about that but I figured that must be why I didn't feel well. So for this current fast I have only been drinking when I feel thirsty and stopping when I feel quenched. I haven't been logging every drink, but I seem to be drinking plenty and I have to go to the bathroom frequently. Indeed it was the need to go to the bathroom that got me up at 2:30 a.m. when I fainted. The info my wife found said I should drink some lemon juice in water and some brine from a pickle jar. I really didn't like the idea of breaking the fast with brine. I did drink one glass of lemon juice and water. So I guess technically I broke my water-only fast.


I'm considering breaking the fast for real and eating some food. I feel fine at the moment and I guess I would prefer to finish the fast for primarily psychological reasons. Rationally I am committed to doing what is best for my health, whether that is fasting or breaking a fast. But it still feels a bit like giving up, laziness, or quitting if I break the fast earlier than I had planned, even if I have a good reason. We are psycho-somatic creatures and I think this psychological element is worth tending to as well as the somatic element. I would appreciate any advice about how to make this decision (I only have about 12 hours left to go anyway).


But mainly I'm more concerned that I've tried relatively moderate length water-only fasts twice now and have had issues both times. Many people are able to fast for much MUCH longer without any issues at all.

Link to comment
Share on other sites

Thomas, fainting when standing is a known occurrence while fasting, mainly due I believe to lowered blood pressure. the scientific term must be something like lypothymy


When I was a young boy I used to faint even when not fasting, I remember a few times I came to my senses on the floor, once even in the bathtub (might have been dangerous).


The dangers due to such phenomenon, AFAIK, are strictly due to the possible hazards while falling down, as it has happened to you.


To avoid that, you should be aware all the time that you must avoid abrupt rising movements.


Probably, there is not a need to stop fasting and I believe 12 more hours will go by fast (accidental pun).


By the way, 12 hours earlier means nothing.


Also, when you say:




Many people are able to fast for much MUCH longer without any issues at all.


That's not a scientific statement. How many people start such a fast? Do you really know how many of'em have no issue at all? Lypothymy is pretty common. As it is extreme tiredness, mental lethargy, hunger, lack of sleep.

Link to comment
Share on other sites

Well it happened again at around 6 p.m. I stood up and tried to hold on tightly to the doorframe in order to stabilize myself. One thing I now know is that when you faint you also lose your grip, so it doesn't really matter if you are holding onto something tightly. I found myself on my back on the floor wondering how I got there. Luckily there was a fresh laundry basket full of clean laundry that broke my fall. If not for that I may have seriously hurt myself.


So that was the last straw and I broke my fast six hours early. I ate just shy of 700 calories, half of those coming from a 1/2 cup of walnuts. The rest of the evening I felt sick.


All in all the last two days of the fast were pretty miserable and I don't think I want to do this again in the same way. Maybe next quarter I will just do a two-day fast? I don't know. I want to learn more. I don't think I'm doing it right.

Link to comment
Share on other sites

Thomas, at this point I'd suggest a more transitional deprivation, like becoming accustomed to Longo's FMD for a few years and then going for the more severe one. The FMD is a walk in the woods compared to only water, I went to work, I slept, I felt almost satiated. 


An alternative is to do 4 or 6 FMDs per year and a few short water-only fasts, like one or 2 days. Even one day per week, like Cloud is doing. 

A 36 hours fast allows you to take advantage of 2 full nights of digestive rest, which is very beneficial to the body.


I am among the wimpy ones who do not tolerate well water-only fasts. I get hungry, very tired, sleepless and mentally letargic. And I break the fast overindulging.


Luckily, Dr. Valter Longo came to our rescue, LOL

Link to comment
Share on other sites

Thomas, I think your wife got it right when she suggested you drink some brine.  There is an effect called the "natriuresis of fasting" or "sodium diuresis of fasting" that you should google.  Basically, when fasting (or highly restricting carbs) the kidneys filter sodium far more effectively.  Total blood volume drops and that leads to lower and less stable blood pressure.  To avoid this problem many need to maintain their normal full sodium intake while fasting and some may need to increase normal sodium intake as much as 3 to 5 grams / day while fasting.   Other electrolytes can also be impacted though not as severely as sodium and some recommend using something with potassium,  magnesium and calcium salts in addition to sodium.

Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...