Also, one thing that I learned: It's good to take in some energy before exercise. I usually tried to squeeze in a meal about 1-1.5 hours before the exercise. When I was very short on time, I ate some shitty replacement like a Mars or Twix instead of an actual meal, but it was still better than not eating anything since you do need energy for exercise. The sugar and quick carbs you get from this kind of food is still better than nothing, but you should avoid it in normal circumstances. If there is no other way on a consistent basis, make some way. Or at least try some fructose instead of plain refined sugar (e.g, Energy Dextrose or something like that, IDK if that's available in the US).