Why do I crave sweets after a workout?

Because you're burning off your glucose and you haven't adapted to fat yet. So it takes a while, one to three months to get into fat adaptation where you're actually a fat burner. You're oxidizing fats and you can work out and pull your fat reserves. If you haven't adapted and you work out, you just deplete your sugar because you're running on sugar. And then now you're going to be craving sugar.