When you are working out to exercise and burn more calories, it is much better to do it while you are still fasting, but near the end of your fast. This way, you burn more calories during the workout, and then you can have your meal once you are done.
Also, it is harder for the body to perform when you have eaten, and everything is focused on digestion, and not on the exercise that you are doing.
Before I started OMAD, I was having a protein shake before I worked out, but then I tried doing it while fasting, and I feel even more energized this way.