'Working on a fast rn, tonight will be 72 hours. Nothing but water, black coffee, and my meds. I haven't had any salt yet on this one, that's new for me (usually I'm having a pickle or two), but so far no signs of diminished electrolytes (muscle cramps).
I'll have some salt water today if I need it (the semi-potassium variety). Maybe a pickle. I do love my pickles.
One thing I learned that is one of those, I-should-have-already-known-this kind of things, is that fasting is naturally catabolic
. Anabolism is building, constructing, integrating. It's building proteins, tissues, including fat or adipose. When you don't eat, you don't build anything, you're instead deconstructing, dissembling, disintegrating, namely, during prolonged or extended fasting, fat. That's catabolism.
Metabolism is kind of the net of your catabolic and anabolic activity. When people say that a skinny person has a "fast metabolism," they mean that their catabolism outweighs their anabolism.
And anabolism (think "anabolic steroids") isn't just building muscle, but also fat. So when you see a fatty like me, it's not that I don't have anabolism, in fact I've done a lot of anabolism to build up my adipose /fat tissue.
Exercise is also of course catabolic, but when you're not fasting the first thing your body is breaking down is its stores of glycogen, which is stored in your muscles and liver, along with whatever blood sugar you already have. In prolonged or extended fasting, your glycogen stores lower down to like zero, so you're in "fat burning" during extended or prolonged fasting. If you exercise while fasting then you're increasing your fat catabolism even further.
Eating is anabolic.
When you eat, your body starts taking the food energy from your gut and it builds tissue with it. First of all, if you eat carbs (starches and sugar) your body releases insulin which imports glucose (blood sugar) into your muscles and liver. Insulin is one of your body's natural anabolic compounds (again, think "anabolic steroids").
Since I'm lifting weights once a week, to build strength and muscle, what I'm really trying to do is optimize my anabolism around lifting. I want to have all my muscles chock full of energy (glycogen, made from carbs, derived from starches and sugar) before I start my workout, and I also want to have my body's natural anabolic compounds streaming through my blood, which includes insulin but also testosterone and growth hormone.
Growth hormone ("human" growth hormone, or "HGH", which is redundant since I am a human) is promoted by prolonged fasting, although I don't know how it is affected once I start eating, which is some time before I start my weekly workout. But testosterone is the primary androgenic anabolic compound, and this is the one I really want to promote in order to achieve good muscle building.
I am still learning, but even before I find the answer I have been, as live experimentation, making sure to eat cholesterol (eggs, butter, meat) because I am under the (perhaps wrong) impression that cholesterol is a precursor to testosterone, meaning that my body can make testosterone from cholesterol so that I'm peaking in testosterone by the time I'm ready to start lifting, which will promote muscle growth.