You add simple carbohydrates PWO for an insulin spike.
Research shows that proper consumption of carbohydrates will enhance your muscle building and fat burning results, not impede them. When the carbohydrate meals were consumed after exercise, glucose oxidation was significantly reduced. In fact, when subjects ate the high carb meal after the moderate intensity exercise session, glucose oxidation was completely suppresed. This lack of glucose oxidation and the fact that a large positive glycogen balance was observed in these subjects indicates that carbs consumed after exercise are exclusively taken up by muscle.
Here is the study I am refering to, if anyone is intrested;
Folch N. Peronnet F, Massicotte D Dulcos M, Lavoie C, Hillaire-Marcel C. Metabolic response to small and large 13C-labeled pasta meals following rest or exercise in man. Bri J. Nutri. (5) 671-680, 2001.