The easiest way to look at it is that you can do light exercise on a dry fast, but avoid everything that is strenuous and makes you sweat. Let's look at some examples and explanations for different situations. If you've ever thought about exercising during your dry fast, you need to read this.
Welcome to the dry fasting club and the beautiful world of dry fasting. I'm Yannick Wolfe and I hope to be able to guide you on your dry fasting journey. Please be advised that none of this is medical advice, but strictly informational. This information is drawn from a cohort of 20 to 40-year-olds, so it may not be a good representation for older and sicker fasters. It also assumes that you have the discipline to adhere to proper preparation, dry fasting principles, and refeeding. Nevertheless, all of this information can be used as supplemental research in your journey. Make sure you join the dry fasting Discord and Twitter groups to keep up with the latest information and engage with other dry fasters. Once again, you can find all of this on dryfastingclub.com where you can sign up, and if this information is helpful to you, you can even choose to subscribe to help out.
Exercising during a dry fast
Exercise and sweating are a no-no during a dry fast. You are already undergoing arguably one of the hardest things in the world, food, and water deprivation. There's a reason people are terrified of dry fasting. To be fair, people are terrified of water fasting as well, but many pleb minds go into shock when thinking about also depriving water. I mean 3 days without water means you can die, right? Wrong! But, the 3-day idea starts to make sense if you consider someone sweating profusely from over-exertion while dry fasting. Imagining someone on a pilgrimage and not drinking water, you can start to see why the 3-day without water myth has some basis in fact. Hard labor and dry fasting don't mix. It's the dose that makes the poison. The body creates metabolic water. You can read about it here Metabolic Water and Fasting | Wet and Dry. So this metabolic water is what allows us to dry fast for periods of 7 to 11 days. But that assumes you are maintaining a delicate balance by not over-exerting yourself. There are reports of going longer, and some crazy people have done it, but it is a bit irresponsible. Some diseases are so pervasive that you'll do anything to try to get rid of them, including attempting to break dry fasting records to 'dehydrate' the parasites, bacteria, or viral persistence. Keep in mind that people posting absurd number claims may be lying, or overexaggerating. Many people in the dry fasting club Discord, for example, claim to do 15 to 21-day dry fasts, but when pressed about it you find out that they take a water fast day in between, or may sip tiny bits of water at certain moments. They still claim it is a dry fast, which confuses others into thinking that they had not ingested any water. This article is not meant to dive into the efficacy of small amounts of water consumption while dry fasting, since that is a topic on its own. The point I'm trying to make is that, to be safe, please be aware that exercising may put you into a big water deficit that metabolic water can't supplement correctly. This can put you into a dangerous dehydration level, and cause net negative effects in the long run.
Exercise during the first day of a dry fast
Exercise during the post-absorptive phase makes sense, but strenuous exercise will strain your body and usually affect the length of the fast. You can find more information about the post-absorptive phase, and all phases of fasting in the article Fasting Mechanisms | Understand Ketosis and Starvation. So the post-absorptive phase is actually around 24 hours from the moment you stop eating. This phase is when the liver uses up a lot of its glycogen stores. About 75% of glucose is supplied from the liver. This is why you can see such drastic weight decreases after the first 24 hours of dry fasting. This weight decrease is also seen in water fasting, but you get to replenish your water reserves constantly so the drop is much less pronounced. Why does this happen? Well, 1 gram of glycogen is usually attached to 3 grams of water. Sometimes even more. While your body is still topped off with extra water reserves, working out makes sense, even semi-exhaustive exercise. It will speed up your glycogen loss and force faster ketogenesis. Finding the right balance is difficult as your window starts to drastically close after 18 hours. Intense sweating is still not recommended, because you're putting too much stress on your internal water reserves. Yes, if you're doing one-day dry fasts, you can play around with this and push some limits. It's what boxers do before a weigh-in, they'll dry fast for 24 hours while sitting in the sauna, pushing their bodies to the limit so that they can make weight for their fight. Afterward, they quickly refeed and rehydrate and suddenly jump 10-15 lbs overnight. A term for this is called death fasting, and you may have heard of it, specifically made popular by Cole Robinson from The Snake Diet.
Exercise during the dry fast preparation period
Exercise before the fast helps lower glycogen quicker and enter ketosis faster. If too much though, you will enter dehydration as your body needs to enter an acidotic crisis to start burning fat at the level it needs to produce adequate metabolic water. This is the approach that I use to 'hack' faster and more intense benefits. If you read the scorch protocol you'll see that I advise a carnivore/zero-carb approach during the preparation which involves a lot of protein but no carbs. This gives you a running start when you enter the dry fast, by putting you into ketosis faster and draining hepatic glucose faster. The benefit of exercising during the preparation period before the dry fast is that you are able to drink water to keep your reserves up, you still take in protein to heal your muscles and preserve them, and you are able to ingest salts/electrolytes that may be lost during sweating and water dumping. Exercising before the dry fast while doing a zero-carb diet also dumps water, since you are losing glycogen. It's much more similar to a water fast, without the nutrient loss. If you've been reading my posts for a while, you'd know that I had been a water faster for over 10 years, but since finding dry fasting, water fasting can kick rocks. Water fasting is simply a tool to prepare your body to transition to dry fasting, a tool for those too weak to dry fast, and a tool for gently exiting a dry fast.
Exercise after your dry fast and during refeeding
I have tested this and talked to others who have also attempted to work out after the dry fast. The longer you have dry fasted, the more dehydrated your body is, and the thicker your blood. Ketones have an inhibitory effect on glycogen uptake by the muscles.
With increasing levels of depleted glycogen the deeper you get into a dry fast, your muscles are not ready for intense exercise for at least a few days afterward. There are a lot of people that have caused injuries to their muscles after trying to work out too quickly after a fast. You need to slowly refeed, and replenish your glycogen stores. This is also why carbs are necessary during the refeed. This is an area that I have pivoted with more experience and research. Turns out Filinov figured this out already, and why having over 30 years of patient experience is so powerful. I used to believe that going ketogenic after the dry fast helped prolong the healing effects and allowed you to kick the carb addiction as well as help with viral diseases. Even though it most likely prolongs the autophagic aspect of a fast, which can help in certain situations, stem cells and muscles require glycogen. There are parts of the body like the erythrocytes, a lot of brain areas, testicles, and kidneys that only run on glucose. So when your body is restarting, your muscles and other areas will be asking for glucose. You won't be producing enough with gluconeogenesis to supply everything to everyone. Your red blood cells and stem cells won't get the required dose to properly heal and proliferate. This is a big aspect that is being ignored and is not taken into consideration by most dry fasting veterans. I go into this in more detail in the Scorch protocol for long covid, and with time I'll update all the protocols with more defined and clear information.
Also, please don't drink baking soda after a dry fast during the refeed. This should only be done in acidic emergencies. Bicarbonate is also known as HCO3. It's a byproduct of your body's metabolism. Your blood brings bicarbonate to your lungs, and then it is exhaled as carbon dioxide. Your kidneys also help regulate bicarbonate. Drinking baking soda disrupts a natural balance in your body. So if you are listening to Dunning or Trevor, think twice about it. Dunning tried to use a scientific hypothesis and included baking soda, and Trevor copied him without asking questions. We've evolved over millions of years, and the body maintains good homeostasis involving bicarbonate, no need to throw it off balance. Also, it contains sodium, which we know we don't want for a few days after the fast since it will cause you to bloat and hold more water (due to the renin-angiotensin-aldosterone system).
I start to lightly workout on day 3 of the refeed. This includes very light workouts where I am not straining at all. Think of it like cardio style working out. Weights that you can easily do 20-30 repetitions with. Don't try to strain at all, don't try to build muscle (even though growth hormone is through the roof). If you're looking to build muscle I'd have to say to start after about 5-7 days of refeeding when you start to feel strong. I'd also have to take into consideration what type of food I am refeeding with. If you have access to high-protein foods like bone broth and eggs, then it will be easier. If you are refeeding strictly vegan or fruitarian, then you are recommended to do even less working out. Remember proteins amplify mTOR and allow your body to enter the building phase. More details about this and refeeding are in this monster refeed article: How to Refeed after a Dry Fast | Filonov Protocol Variation
Exercise by walking during a dry fast
Walking is great. Walking too much is scary. No walking at all is bad for both mental and lymph clearing. Read more about it here: Mental State and Dry Fasting. Filonov says: "You need to know that the body requires three times as much fresh air when fasting. Do take walks!!! When you feel weak and nauseous and want to stop the fast, fight fire with fire – move around and walk a lot. Physical activity makes all the organs and muscles work, pumps the blood around, and quickens the cleansing."
Walking helps with lymph clearing, which is super important during a dry fast especially since your blood thickens as your water concentration slowly drops. This water decrease is a vital part of why dry fasting provides such powerful healing. It's called a hyperosmotic environment and is critical to activating things like microtubule repair. Let's also not forget that there is a correlation between aging and increased cellular dead water, as well as lipofuscin. Both of these I believe are targeted during dry fasting, which causes an anti-aging rejuvenation effect. Not many people are aware of this. When you get to remove this heavy toxic water, which is also composed of deuterium, you get to replace it with deuterium-depleted water. Our foods contain different ratios of deuterium, with higher latitudes having less deuterium. This is important because higher latitudes get less sunlight, an important factor for health. If we had less sunlight AND higher deuterium food we'd be in a bit of a pickle.
I've experimented with doing a 200-hour (9-day) dry fast isolated indoors while stuck in a room. It was the hardest fast for me mentally because I did not get to go on walks. I did yoga and stretching for lymph movement, but there was a missing aspect and I attribute that to not being in nature. In fact, a Japanese study looked at the benefits of 'forest-walking' in their study: Effect of forest bathing trips on human immune function.
Participants took 3-day/2-night trips to forests, and their blood and urine were tested during and after the trips. Tests focused on natural killer (NK) cell activity and other immune system markers, as well as stress hormone levels. Results showed that forest bathing significantly increased NK cell activity and other immune markers, while reducing stress hormone levels. The immune-boosting effects lasted for over 30 days, suggesting that a monthly forest trip could help maintain better immune function. However, city visits did not provide the same benefits. This suggests that forest bathing can improve immune function through increased NK cell activity and other immune system components.
Wrapping this up with the main insights and some key discoveries below (sign up for free to read it!)
Not only does walking help with mood, better air quality light exposure, and lymph circulation. In fact, it shows that it boosts the immune system markers. Since one of the most important aspects of fasting is the revitalization of your immune system, we should take every immune-boosting benefit seriously. It's also why I'm a big proponent of cold plunges during a dry fast. I used to believe that hard dry fasting was the strongest fast, but I've upgraded to include cold plunges. Without going into too much detail (look out for a cold plunge tutorial with a dry fasting article soon), warm or tepid water on an extended dry fast is bad as it promotes water absorption and disruption of a lot of dry fasting benefits, while cold water constricts the cells and minimizes absorption, while at the same time increases lymph movement and blood flow, which translates to better nutrient and energy distribution.