Hello Julia Conaway,
There really isn’t a simple answer. The article Harris supplies explains it nicely enough to understand what is going on; but, no one really knows the exact moment. I like the tip to exercise first thing in the day vs. the end of the day; but, please, be prepared with some nourishment if you decide to go out without breakfast. Safety is number one, along with health, then the body will be able to adapt to perform the workouts and reap benefits. But, you already know this, of course.
Natalie aka NAPS 2 B Fit.