Questions about water fasting

Hello fellow water fasters. I want to do an extended water fast, more than 3 days. I really need to understand how the depletion of glucose and the utilization of muscle protein in order to fuel the body works. Basically, I have read numerous times on so many different websites that we will lose a lot of muscle while Water Fasting for this long (more than 10 days). I want to know if this is true or not, and if it is, how to minimize muscle loss during this time. I am a 5'4" 18 year old male that has quite a bit of muscle mass and would like to certainly keep the majority of it, anyway.

I also want to know why exactly it takes 3 days to enter this ketosis state. I have read in many places that you enter ketosis when glucose runs low in your body, so in that case, is doing a glucose burning workout like running for 90+ minutes (or until you experience the bonking phase), then proceeding to fast a better option, to not have to wait 3 days to enter ketosis?

I'm already familiar with the concept that strenuous exercise while fasting is not good for you, but I assume the reason being is that you will start to use the protein in your muscles to fuel a heavy workout while fasting.

Does anyone have any insight on this? Thank you so much!!! Tweet