Fasting or Exercising


(Hui Xiong) #1

So I have been doing keto on and off since last year. I tried to keep a regular routine of 6 days fast and eating on the sabbath, Friday night to Saturday night. Over time I found myself weakening in this area because family, friends and mentors all have challenged me on this. I have doubts about it myself but the science so far is solid, although I the long-term consequences have still not been demonstrated. Doctors themselves do not seem to have a consensus.

I am resuming and trying to again fast for 6 days every week. The doubt now is 1)am I trading exercise for keto. That is, my brains tricks me to eat by saying things like you can eat then you have energy to exercise. And 2) my body feels pretty miserable right now, around 36 hours into the fast. I used to feel a head high throughout the 6 days with intense focus and great spiritual pleasures (read: achievements) but my body doesn’t like this very much. I believe in the importance of getting my body onboard. How do I make the body happy as well as the mind?

Look forward to your thoughts.

(Joey) #2

@Hui_Xiong Welcome to the forum!

To be honest, what you are doing sounds kind of scary to me…

What are you trying to accomplish by extended fasting? I’m wondering whether your weakening is a real problem - not just robbing you of energy to exercise but creating an even larger problem.

My fear for you is that you are forcing your metabolism to s-l-o-w down because you are starving yourself. You are treating your body like you are in a prison camp - not usually good for one’s health.

Can you elaborate on what your perceived problem is that you are trying to address? Weight? Disease? General health?

Fasting is useful (to a managed extent) for certain issues. And it is not terribly effective at addressing other issues. Elaborating on your goals will be helpful in providing context.

If spirituality is a key goal, there are other ways to lead a spiritual life without missing 6 out of 7 days of nourishment (for your precious once-per-lifetime body).

(David Cooke) #3

I am guessing that you are doing exercise because you want to lose weight.
Calories in, calories out, right? Well I don’t think anyone here will agree with that approach, even though many do regard this forum as a weight loss forum and not a health forum.
Get your diet right, start losing weight and then think about exercise to maintain the health benefits that you.
You may then get into i9ntermittent fasting, I wouldn’t do extended fasts as you are trying without very careful consideration.

(Hui Xiong) #4

Appreciate your input. No, I am doing it for the mental sharpness. I am quite lean already but there is research in rats and other animals that as animals lose weight they experience a paradoxical increase in energy. That’s what I am looking for. I want to exercise more for muscular structure and overall health, not to lose weight.

(Hui Xiong) #5

Appreciate it. It’s mostly for sharpness and perseverance in work. My doctor said that my blood test showed that my cholesterol levels were excellent. That was when I was fasting, regularly as I mentioned above, roughly 4-5 days a week. The reduction is sleep is also something I am aiming for. 5 hours per day compared to 8 will add up over time. This is especially important since lockdown meant no gyms - nowhere to burn off the calories that I take in and release the drudgery related to the food.

The only major problem is constipation, for which I bought magnesium citrate.

(Joey) #6

Mag citrate is an essential ingredient to manage keto-constipation, along with keeping electrolytes up in general.

As for mental acuity, I hear you … my concentration/focus took off after cutting out the carbs. But fasting for 6 days will catch up with you at some point. Your body will rebel - it’s too little, too often.

For me, meditation, tai chi, qi gung, … there are plenty of ways to keep your mind in top shape without depriving yourself of nutrition.

Food for thought. :vulcan_salute:

(Michael - When reality fails to meet expectations, the problem is not reality.) #7

Have you considered daily intermittent fasting or alternate day fasting as an alternative to what you’re doing now? The mental clarity and alertness would likely be the same. Unless you’re consuming 6 days worth of food on that 1 day of eating what you’re doing now seems like a recipe for disaster. Just my opinion. I only do overnight IF (~12 hours) 3 or 4 times per week so I’m no expert about fasting. But this seems rather extreme.

(Hui Xiong) #8

Thanks man. I do suspect it can get too much. I have strange dreams, one of which I felt that my spirit drawn up by an unknown entity, hopefully it wasn’t the angel of death. But many people here do long fasts, like 10, 20 or even 30 days. At least I eat once a week, plus there are occasions when it is holy to eat aside from that, festivals and circumcisions.

I do a bit of that but I find that I am slacking in my performance overall because I have been slacking in my fasting routine.

Appreciate the hand sign for the priestly blessings.

(Hui Xiong) #9

Thanks. It seems like you are saying that the disaster will be because of a lack of nutrition? I appreciate the concern. What about people who go on bouts of long fasts, up to 40 days?

(Michael - When reality fails to meet expectations, the problem is not reality.) #10

From lack of necessary nutrients, both macro and micro, and negative energy balance over a long period of time. Folks who can do long fasts start with a lot of onboard stored energy (fat). If you eat enough and smart enough on your one day I suppose you could sustain it quite a while. The danger is that just like real starvation, you eventually eat yourself to death, muscle mass first, then bone density, then non-vital organs, finally one or more vital organ shuts down and it’s over. If you want to test the reduced calories increased longevity hypothesis, I wish you well, but recommend you get your affairs in order just in case it doesn’t work out the way you hope for. If you do so, please keep us informed. I strongly suggest you start with plain keto for at least a few months or a year to see if that accomplishes what you want before trying what you’re doing. I think keto leads to good health, well-being and longevity. It’s at least worth a sustained trial. Whatever you decide to do, I wish you well.


Nobody ever got muscular from not eating for 6 days at a time… NOT gonna happen my friend. Start eating, eat good clean foods and your mind will be fine. You want mental sharpness, muscle, and you’re not going for fat loss, not eating for days on end makes no sense for you.

I’m also saying this as somebody that destroyed their metabolism with fasting like that, don’t be me! Took me a LONG time to fix it.

Also, you’re not a rat! All “science” doesn’t apply to you/us. Don’t try to do every thing some random study says works.

(Hui Xiong) #12

Thank you all so much for your genuinely caring posts. But what separates me from people who do long-term fasts? Why is my approach more dangerous?

(Vic) #13

Welcome to the forum Hui

Go full carnivore then.
2 meals a day, fresh animal fatty only.

The energy denser the food the better.
No fasting longer than 16h.
Hunger leads to waisting your time, so eat enough.


The fact that you plan starving for a long tome.
Long-term fasts are even longer but a well-stocked body can handle it once. If they eat for some days and start ANOTHER 40 day fast… Well that is very dangerous too. Or doing a single one when one doesn’t have enough fat to sustain it. I admit I know very very little about these things, I never would do more than a few days long fasts because of multiple reasons (for example, no way I wouldn’t lose muscles and I don’t do that. the body needs its nutrients) and I don’t actually know how people handle such long fasts, I merely know some people seems fine during them, but there are facts. Almost never eating, it results in problems and death, it’s clear. I don’t know how long do you want to do it but once in a blue moon is plenty (and I wouldn’t do that, 6 days may be long enough to slow down metabolism… maybe it quickens back easily and it’s probably individual… but still, a few days seems safer and enough).
Longer term? No, your body run out of nutrients, start to take apart itself, lowers metabolism, functions worse… Why would anyone do that?

Proper sleep is very important too. I need my 7 hours, no matter what. It’s individual but if your body wants more than 5 hours, give it more than 5 hours.

No 16+ hour fasts sound horrible to me, actually. I usually need longer ones, there is nothing wrong with that. Each to their own.

What do you mean hunger wastes time?

(Vic) #15

I some culture, efficiency in work means everything.

Hui aims for “sharpness and perserverance in work”.

If you are hungry, yourr brain is preoccupied and work becomes less efficient with more mistakes.

(Bacon by any other name would taste just as great.) #16

Forty-day fasts come pretty close to the limit of what the body can tolerate. In my spiritual tradition, your spiritual advisor would want to be very sure of your reasons for engaging in such a fast before permitting it. (For example, the desire to take pride in such an achievement would not be considered a healthy motivation.)

The one really long-term medical fast I know of was the case of Angus Barbieri, a grossly overweight Glaswegian 27-year-old, who fasted for 382 days. The fast was originally intended to be much shorter, but he persuaded his doctors to allow him to continue, and they agreed, so long as he came in regularly for checkups.

The case was written up by Stewart & Fleming, “Features of a successful therapeutic fast of 382 days’ duration,” Postgraduate Medical Journal (March 1973), 49:203–209. The authors begin by noting that

Current opinion on fasting therapy for the obese is perhaps best summarized by the view that fasting for relatively short periods is beneficial, whereas longer term fasting (i.e. longer than 40 days) has an element of risk attached (Lawlor & Wells, 1971). It is generally agreed that the long-term outlook for the achievement and maintenance of ideal body weight is poor (MacCuish, Munro & Duncan, 1968; Lawlor & Wells 1971) unless a weight close to the ideal is achieved during the supervised phase (Munro et al., 1970), a process which in the majority of cases would involve a prolonged rather than a short-term fast."

They then go on to describe Mr. Barbieri’s experience and the treatments and tests administered during the fast. He weighed 456 lb./207.3 kg before undertaking the fast. “Initially, there was no intention of making his fast a protracted one, but since he adapted so well and was eager to reach his ‘ideal’ weight, his fast was continued into what is presently the longest recorded fast.” He was given vitamin supplements daily, along with vitamin C and yeast. Non-caloric fluids were allowed ad libitum. At one point he received potassium supplements, at another sodium. At the end of his fast, Mr. Barbieri weighed 180 lb./81.8 kg, and his weight remained stable at 196 lb./89.1 kg five years later.

(Hui Xiong) #17

I appreciate your thoughts.

I was a researcher who worked closely with Dr. Jordan Peterson. I have diverged from him in stark and adversarial ways. I am also committing to eating less meat to fulfill the biblical commandment to prevent tzar baalei chai (suffering to animals) and out of a protectiveness toward the environment. I am currently looking for humane options for meat because I recognize that it is nutrient dense.

I don’t personally find hunger to be an issue in efficiency. I see it as mistreating my own animal body, but I also understand that it is only the beginning phases. It’s like quitting any unhealthy habit that there should be discomfort.

(Hui Xiong) #18

That’s very insightful Paul. Do you think I can pull regular 6 day fasts with supplements and water?

(Hui Xiong) #19

I am about 173 cm and 70 kg. My fasts barely put a dent on my weight. I figure I’d be happy at 65 kg. That’s plenty of fat to burn through before then.

(Jack Bennett) #20

It feels extreme to me but then again a regular 16:8 or 18:6 sounds extreme to some people.

Based on what I’ve read, the main risk I would expect is repeated loss of lean tissue during the fasting windows (maybe 1.5 lb of muscle lost every week?). Most people who do multi-day fasts only do one such fast every month or two. I’ve never heard of anyone doing a 6 days off / one day on fasting scheme for a sustained period. Maybe you’ll be able to report back on your findings.