Both creatine and protein supplementation have each been shown in prior studies to augment adaptations to resistance training. It remains unclear however if the combination of these two scientifically validated supplementation strategies would be additive. Australian researchers tested this idea in three groups of resistance-trained men who all performed a 10-week resistance-training program. One group received protein only (~103 g whey isolate per day). Another group received a combination of protein and carbohydrate (~52 g whey isolate and ~59 g glucose per day). A third group received a combination of protein, carbohydrate and creatine (~48 g whey isolate, ~53 g glucose, and 8.4 g creatine monohydrate per day). Supplements were consumed 3 times per day. Increases in lean body mass in the protein and protein-carbohydrate supplement groups were similar (~10 pounds), whereas the protein-carbohydrate-creatine group increased lean body mass by an average of more than 15 pounds. Muscle biopsy samples were taken from the leg and showed that there was also a greater increase in the size of muscle fibers in the protein-carbohydrate-creatine group, as well as greater increases in maximal strength. These results are novel and important, showing that the combination of protein and creatine promotes the optimal anabolic environment to support muscle growth and strength.
Cribb PJ, Williams AD, Hayes A. A creatine-protein-carbohydrate supplement enhances responses to resistance training. Med Sci Sports Exerc. 2007 Nov;39(11):1960-8.