Do you still think "100% whey" is best? Stop living in the past.
Do you still drink 100% whey protein is best? Stop living in the past! Research indicates that a blend of casein and whey is more beneficial for athletes than simply supplementing whey protein alone. Researchers discovered that whey and casein work together in synergy. That means taking both together is better than simply taking one or the other (1,2).
Taking whey protein alone only gets you so far. It can spike protein synthesis rapidly, but you also return to baseline rapidly. Casein, a slower-digesting protein on the other hand, promotes a steady release of amino acids over time. In fact, casein results in more retention of ingested protein than whey.
Researchers have also found that the combination of whey protein with casein protein resulted in a rapid increase in protein synthesis along with a sustained elevation in plasma leucine levels…essentially meaning, the best of both worlds (3). Plasma leucine levels are a key dictator of muscle protein synthesis (think of it as a building block for building muscle); therefore a combination of the two proteins is optimal in order to maximize protein accumulation.
With a combination of the two, you get the perfect mix; whey protein hits the bloodstream at a fast rate, while casein protein has been shown to create the strongest leucine balance (4). In fact, the 2005 International Whey Conference concluded that a 50/50 mixture of whey + casein is the optimal form of protein for gaining muscle mass (3). It only makes sense to consume them together, science says so!
- Soop, Mattias, et al. "Coingestion of Whey Protein and Casein in a Mixed Meal: Demonstration of a More Sustained Anabolic Effect of Casein." American Journal of Physiology (2012): n. pag. Print.
- Lacroix M, Bos C, Leonil J, et al. "Compared with casein or total milk protein, digestion of milk soluble proteins is too rapid to sustain the anabolic postprandial amino acid requirement." Am J Clin Nutr. 2006 Nov;84(5):1070-1079.
- Phillips, SM. Eating the Right Proteins to Support Muscle Mass with Exercise. Presentation at the 4th International Whey Conference, 2005.
- Reitelseder, Soren, et al. "Whey and Casein Labeled with L-[1-13C]leucine and Muscle Protein Synthesis: Effect of Resistance Exercise and Protein Ingestion." American Journal of Physiology Endocrinology and Metabolism 300 (2011).