Carbohydrates are needed in conjunction with protein/amino acids. This will give you the most anabolic effect.
My favorite drink is Vendetta. Clicking this link takes you to the product and gives you a scientific background on pre/post workout nutrition. If your into being your own scientist like I am, I prefer Waxy Maize Starch (Vitargo), Creatine, BCAA's, and Whey Hydro. If you have the money, you can't really go wrong just buying Vendetta (or similar product), and downing some before, during, and after training.
http://www.1fast400.com/?products_id=670