Creatine monohydrate (Cr) and Whey Protein (WP) are the two supplements commonly used by athletes in order to promote muscle hypertrophy and strength gains during exercise.
Whey protein contains higher essential amino acid (EAA) concentrations than other protein sources and has fast absorption rate. Common strategy among bodybuilders is chronic use of creatine monohydrate in order to increase muscle strength and lean body mass. The effectiveness of creatine monohydrate is highly dependent on its accumulation in the muscle.
Cribb, Paul J., et al. examined the effects of combining creatine with carbohydrates and with whey protein during resistance-training in comparison to whey protein and carbohydrates alone, on strength, body composition and hypertrophy. Twenty-six male bodybuilders were divided into 4 groups [7 = CH (carbohydrates), 5 = WP (whey protein), 8 = CrCH (creatine + carbohydrates) and 6 = CrWP (creatine + whey protein)]. The most significant gains were in CrCH (+3.7kg), CrWP (+3.4) and WP (+2,4) groups. These groups also demonstrated a greater increase in strength in each exercise compared to the CH group.
The most important finding of this study was that CrCH, WP and CrWP groups resulted in greater hypertrophy response compared to carbohydrate only group.
Cribb, Paul J., et al. “Effects of whey isolate, creatine and resistance training on muscle hypertrophy.” Medicine & Science in Sports & Exercise 39.2 (2007): 298-307.
Bucci, Luke R., and Lisa Unlu. “Proteins and amino acid supplements in exercise and sport.” Energy-Yielding Macronutrients and Energy Metabolism in Sports Nutrition (2000): 191-212.
Dangin, Martial, et al. “The rate of protein digestion affects protein gain differently during aging in humans.” The Journal of physiology 549.2 (2004): 635-644.
Rawson, ERIC S., and JEFF S. Volek. “Effects of creatine supplementation and resistance training on muscle strength and weightlifting performance.” Journal of Strength and Conditioning Research 17.4 (2003): 822-831.
Hultman, E., et al. “Muscle creatine loading in men.” Journal of Applied Physiology 81.1 (1996): 232-237.