I have chronic fatigue as well. I didn't seem to have it on my fast which was 31 water,3 juice, 2 water ,4 juice.
It went away and was hoping for good but seems to have come back post fast.
It might have something to do with food allergies . Maybe gluten not sure but don't seem to get usual gluten allergy symptoms, not much bloating,or gas so not sure.

You could try longer juice fast or maybe juice 5 days then water 2 or vary things a bit . Juice gives way more energy and less problems with low blood pressure, fainting,etc.

Wife went 28 days on her first fast on juice.
I was hoping my Water Fast would cure few of my conditions and the chronic fatigue is one of my worst problems. Had it for years and doctors never found reason. Checked me for diabetes,low testosterone,etc.etc but found zip.

Losing nearly 40 pounds from starting weight has helped some and at least am doing exercise 5x week aerobic type and 3x week weights post fast. Was doing the 5x week pre and during the fast but started up the weights post fast.Still the fatigue is very annoying and its not a feel like sleeping type of fatigue.

I will likely be doing a shorter more pure type water fast
in next month or two. Would like to go like 14 water with 3 juice or so pre and 4 juice or so after for 20 total.
40 day fasts are brutally long.Even 30 gets very boring.

Be watching your post to see how you do on the fast.
Low blood pressure is pretty normal. You are not taking in any sodium with pure water fast.Also be sure to drink when thirsty don't try to drink 8 to 10 glasses like I did. Think that was mistake. Flushes all the sodium and potassium out of your system not a good thing when fasting.
I took some potassium pills and maybe should have took sodium ones. Day 32 just started drinking juice ,high sodium juice and it really helped me. Felt much better. And had some potassium in the juice as well.

Energy was way way better on juice. Fact should do juice fast for week or two and see how the fatigue is. After all if it is something like gluten should be much better on juice only.If its still bad on juice maybe its carb problem.

Yes its a good idea and you will have far less of the detox symptoms that probs doesnt help your situation to start with. Those with time on there hands should cut down each day and start going "raw-er" with each meal until your 100% raw, then do the same with juice until your 100% juice then ease into it with water the same way. However, this approach requires a strong motivation to not overeat and stick to the prep, it also requires time which most of us never have.

Hello cigana!

If I understand it correctly when the body enters the promise land of Ketosis, it’s using your fat as a fuel instead of Sugar or glycogen. When you feel crap it’s your old trash talking to you. So when you sip your juice not doubt you feel OK. The moment you sip your juice the body switch from fat fuel (ketone) to glucose fuel. So feeling good is like delaying the healing.

The very idea of Water Fast is to get rid of your metabolic waste. The way to feel better is by getting rid of some of the metabolic waste dislodged from your fat cells into your blood via your skin.
What you are doing is just back and forth from the land of ketosis to the land of glucose. It’s like chasing your metabolic waste from one part of the body to the other without any out let.

Find ways to chase away your toxin out of your body and feel better.

Good Luck!