Fasting - workouts - Fat loss vs Muscle loss?

So I have been water fasting since Monday at 11:30 pm (I am currently 5’7" at 170lbs) and did tuesdays workout then abs then 15 minutes of yoga. tuesday night did I Taku still fasting and Wednesdays workout and another yoga session for a total of 36 hours fasted (minus 37mg of caffeine and 30 calories a day from gummy vites but im over 50 soo those are needed) I am mostly concerned about keeping my muscle mass but its hard to figure out even with a scale. where can I find more information on whats going on with my body? on that note I feel physically and mentally great.

For what it’s worth. Experimented with fasting, did longer and longer fast (from skipping breakfest to 2 days on purely water), incorporated some longer rides on just water (some went better than others). Wanted to really push the limit to see where I could go, got to 131lbs and did a 20min ftp test (347w so I was flying). Recovered and ate, tried doing the same thing for the san dimas stage race and struggled holding 290-300 (I would have been much faster being heavier with more power). Anyways, did some blood testing and my parameters where out of whack so I stopped, rode less and weight lifted. I think it’s fair to say you probably loose muscle at the same rate of loosing fat, but what you can’t see is the stress on your organs/bones. Fast at your own risk and maybe don’t push it too far.

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Some of the Valter Longo studies I’ve read indicate that there is muscle loss during the fast but it comes back very quickly as you start eating again and you get this regenerative spurt.

RLucky82, that sounds like a lot of working out. Longo only advises very light activity.

You could do a Dexa scan if you wanted to accurately measure muscle mass and body fat.

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I forgot to say that I am 5’7" and 170lbs down from 180lbs So I have plenty of fat to lose. I know alot of people here are already close to the recommended body weight but I am not one.
I do have the Tanita BC554 scale but the measurements are not as easy to read as one might think. for example there is a big difference between how much meat you have in your system or not and if I take a reading the day after a hard ride my muscle mass takes a hit and rebounds on a the day after recovery (pre ride), the difference can be 4 pounds of mm. So, on that note it’s really just averages. I was hoping someone would have some good articles I could read.

I doubt your muscle mass is taking a big day to day hit. A Tanita needs a consistent level of hydration. My guess is that your hydration has been affected the day after a big bike ride. Maybe your muscle glycogen is depleted. If you are doing these measures while on a water fast they may not even be remotely accurate.

If you are dieting and want to maintain muscle mass, eat plenty of protein. For example, I’m currently doing a 5 x 20gram (minimum) per day dose of protein while I’m dieting during my base mile training. Usually I hit 150-170 grams per day but the idea is to space it out and kick off muscle building many times per day.

I’d highly recommend reading/listening to some of the Longo work. I found these two podcasts very informative.

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AKA disordered eating