To eat or not to eat prior to exercise, that is the question!
There are several factors that go into this decision:
What is your daily nutrition? Mine - I’m animal-based, low-carb ketogenic. This means that I maintain my carbohydrate intake to less than 5% of my overall nutrition. I generally consume 60% fats and 35% protein.
How often do you exercise? Me - daily cardio/weight training, and swimming 2-3 times a week.
What is your goal? Mine - live until 120, swim into my 100s, and maintain overall general good health.
My preference? I prefer to exercise in a fasted state. Eating anything before exercise tends to make me feel sluggish, whether in the gym or in the water. If I’m putting in a double workout, cardio/strength training in the morning (0600) and a swim in the afternoon (1500), I eat breakfast after my morning workout and dinner after I swim.
Caution - The more carbohydrate dependent you are, the more difficult it is to exercise in a fasted state.
When not to exercise fasted - if you feel dizzy or nauseous, stop exercising and get some fats and proteins (bacon and eggs).