Working out while fasting can be a powerful combo for fat loss - mental clarity - and discipline, but it’s not a one-size-fits-all approach. Since getting involved in IF, I have started working out 4 days a week at a local gym. And when I work out it’s usually always in the morning on an empty, fasted stomach. And I feel great. So let’s talk about how the other guys in the gym that work out with me feel that they have to have something like a protein shake or a breakfast on their stomach, and can’t understand how I can go like them on anempty stomach.

Here’s a breakdown of what’s involved, based on physiology and practical experience.