Dry fast and workout

[Marius1793]

Hello if someone train with weight during the 5 days dry fast you think it will amplify autophagy? So 5 days dry fast with workout = 7 days dry fast without workout

[Yannick]

No, I used to believe that weight training during dry fasting made sense to speed up dehydration, but over the years I've realized that the body has perfected the slow dehydration of a dry fast (with no extra exercise), and that exercising and causing sweat and exertion during a dry fast only means to speed up the dehydration and with it, complications and possible dangers. THe only type of exercise should be stretching or very light walking.

Building muscles while fasting is also impossible as you require calories to build muscle, but fasting in itself should be muscle sparing as long as you don't over-exert.

- **Beneficial Group:** Those who walked <3 km/day with HR <100 bpm → symptom improvement +22% vs bed rest
- **Detrimental Group:** Those who walked >5 km/day or HR >110 bpm → excessive water loss, symptom worsening
- **Optimal Zone:** 2-3 km/day at conversational pace

Walking and light exercise were found to be beneficial *only* if they did not lead to excessive perspiration (water loss), indicating that "metabolic movement" is a key component of the fast.

**Mechanism:**
- **Lymphatic pump:** Movement enhances lymph flow (no muscular pump in lymph system)
- **Metabolic stimulation:** Mild activity maintains muscle insulin sensitivity
- **Psychological benefit:** Reduces boredom and anxiety during fast
- **Limit:** Must not exceed water loss threshold (~200 mL perspiration total)

[meow]

I dont think it was "weight training," but I have experience with carrying very heavy things and shoveling snow a lot while fasting.
I would not recommend doing this until the 2nd-3rd day - you will hit dehydration faster than body will adapt, greatly reducing fast.
During day 3, I just dont have the opportunity to act too fast because of the high hr, so looks like the risk of dehydration is significantly reduced - I exhale and rest before I start sweating.
Its also worth noting that its cold enough in my area, so I can function adequately during the heat.
What I always do while fasting is light core training, running with expander(~3.5-5km, depending on conditions) and walking a lot(25-35k steps), this is being tolerated quite well, breaking the recent fast, I felt very stable and that I could hold out for at least another day.
but it is very important not to overload yourself in the first few days and give your body some time to stabilize in a calm environment after workouts, otherwise you will not be able to stand even for 3 days.
also, speaking of muscles..

Building muscles while fasting is also impossible as you require calories to build muscle, but fasting in itself should be muscle sparing as long as you don't over-exert.

I always end dry fasts with x1.5-2 muscle gains, especially noticeable in the shoulders and arms.
and after I gave up keto, they even remained a week after fasting (usually disappeared).

with regard to autophagy, it seems that the 1st crisis comes earlier if you overload yourself - for me it was the end of day 2, it usually came on day 2.5.
but due to too much dehydration, your chances of surviving it are low. one of the times I ended up drinking at night because the thermoregulation system was too messed up - I was thrown from extreme heat to cold alternately, which did not allow me to sleep.
An interesting fact is that after 2.5 hours of gradual drinking, my apartment was flooded with hot water. so maybe it even saved my health - imagine being asleep in a sauna in a state of noticeable dehydration.

[Marius1793]

Only a DEXA scan can tell you whether you’ve lost muscle or not during fasting. You shouldn’t rely on visual appearance… I made that mistake myself.
The two things that can give you reliable information are a DEXA scan and bone density. That’s why long fasts, especially over the long term, can create muscular issues. Fasting should be used as a tool, not as a constant practice.
Yannick even says: “Why do you want to fast if everything is fine?”
He’s right in a way: the body does adapt to fasting, yes, but there are side effects on the hormonal system. That’s why you’ll never see fasters who are truly muscular.
I lost 12 kg of muscle, with my testosterone divided by three, two years ago after 17 days of water fasting, preceded by 2 days of dry fasting. It was very difficult to recover my hormones — it took two months.
Mentally, I felt very good afterward.
From a muscular standpoint, however, there was a major loss of strength, and it took months for it to come back.
Dominic D’Agostino had the same problem, like many others who measured everything with blood tests, scans, etc.

[Yannick]

Yes it's safe to say you never gain muscle on a fast. What you are seeing is increased definition of muscle. Now if you argue that you barely lose mucle, then quickly regain muscle after the fast from better nutrient partitioning, we have a case lol. Even a 3 day dry fast according to russian research was something like 0.6lbs of muscle got lost, which was something like 0.38% of lean muscle mass, so a small amount, compared to water fasting.

| Parameter | Dry Fasting (3 days) | Wet Fasting (7 days) |
|-----------|----------------------|---------------------|
| Total Weight Loss | 3.3 kg | 3.8 kg |
| Fat Loss | 1.4 kg (41%) | 1.2 kg (32%) |
| Water Loss | 1.6 kg (49%) | 1.8 kg (47%) |
| Protein Loss | 0.3 kg (10%) | 0.8 kg (21%) |
| RQ (final) | 0.71 (deep ketosis) | 0.76 (moderate ketosis) |
| Visceral Fat Loss | Preferential | Mixed |