During fasting, your body burns fat, not muscle. What looks like muscle loss on scales is mostly water leaving your glycogen stores. A 10-day study at Germany's Buchinger Clinic measured grip strength directly and found it didn't decline, proving fasting doesn't weaken you.
sarcopenia. And that's, that's a very interesting thing because that's been studied forever. Because when you fast, your body predominantly oxidizes fat, not muscle. So if you're burning fat, you're not burning muscle. Your muscles do get smaller because they're burning their glycogen, which has water. So that, but that's not muscle. Glycogen is not muscle fiber. When they've done the study, and I just reviewed it in my last blog, actually, there's a— they did a 10-day fast in this clinic in Germany, and they measured— so, so the way— the reason people worry about muscle loss is because of the way it's being measured. So when you measure it, you do this, you either do bioimpedance or you do DEXA. Both of them, in both of those, body water is very similar to body fat. So when you do bioimpedance, you send an electrical pulse through the body, then this is the things where you step on that scale that tells you the body fat, right? Sends an electrical pulse and it measures how, how much it is. But body water looks the same as body fat on these scans. So when you lose body water, such as what happens with fasting, it looks like you're losing lean tissue, right? So the lean muscle looks like it's being lost. And so what they did in this Buchinger Clinic study is they did put people on a 10-day fast, right? A really long fast, longer than most people do. And then they measured the strength directly. They told people, how much can you lift? What is your maximum grip strength? How long can you do this grip strength? What they found was fascinating because in— if you look at non-weight-bearing muscles, the strength did not go down.
