I do weight training and running. Usually after a workout I feel like the cravings I do have are more manageable. You do need to be careful though. I wouldn't recommend doing any weight training if you're doing more than a 24 hour fast and if you are weight training while fasting make sure you have a spotter. At least at first.
When doing cardio, I feel like I have more energy fasted than if I eat before. That might not be normal, might just be what I'm used to.