It depends on what your ultimate goal is. If you want to emphasize the training of muscle circumference, you must eat creatine and protein powder, and then eat after exercise, preferably half an hour apart. If you just want to lose fat and keep healthy, it is ok to eat protein powder, and then eat it after exercise. In addition, you can't help eating before exercise. Burning fat and carbohydrates is fuel. If the blood sugar in the blood cannot be supplied to the body, it will consume fat, but at the same time it will also consume muscle, which will slow down the basal metabolism, which is not conducive to weight loss, and fasting exercise is not good for the body. It is recommended to supplement digestible carbohydrates half an hour before exercise.