Protein is considered by many to be the most important macronutrient for humans because of the numerous roles protein plays in the body. Protein needs have been compared across several population groups, including athletes and other exercising individuals. Many researchers have compared the effects of ingesting animal and vegetable protein sources and their implications on sports performance. Recently, blends of dairy protein and soy protein have appeared in commercial sports nutrition products such as nutrition bars and ready-to-drink and powdered beverages. This review will focus on the potential nutritional advantages of combining whey protein, casein, and isolated soy protein.