Steve
Everyone is different so it's best to experiment.If you exercise in a fasted state you'll burn fat for energy as glycogen stores are already depleted so working out fasted is great.Some people feel dizzy or unwell doing this however so if you try it go slow and listen to your body.Personally I do 16/8 (eat in an 8 hour window) 5 days a week and have breakfast before exercising as I felt a bit sick couple times exercising while fasted.However I've done an 84 hour fast before and exercised during that and didn't feel loss of energy or sick, I think the times I felt sick it was my body adapting.I'm sure if I started exercising now fasted I'd be fine as have done it a lot longer now, the sick feeling was when I'd just start experimenting with fasting.So try both and see how you feel, exercising fasted is just my personal preference now.Good luck💪