Supplement Research - Post-Workout Recovery Supplementation Update

By Robbie Durand, M.A.

Senior Science Editor

Whey Versus Casein Rematch!

            Milk proteins (~20 percent whey and ~80 percent casein) are the superior source of post-workout protein, compared to other lower-quality proteins such as soy— which bodybuilders rarely use anyway. As previously reported in Muscular Development, whey has been characterized as a “fast” protein and casein as “slow” protein due to their digestion and absorption rates. Interestingly, casein was previously demonstrated to have the best effects on maintaining long-term protein kinetics, as whey is a relatively fast protein in terms of digestion and absorption. The insulin responses to whey protein are much higher than that of casein, which may contribute to the enhanced anabolic response.

            What does the research tell us about whey versus casein? Researchers had men perform an acute, heavy resistance exercise bout consisting of 10 sets with 8 reps at a pre-determined load corresponding to 80 percent of one-repetition maximum (1RM). Subjects rested between sets for three minutes, and immediately after completion of the exercise, participants received a drink containing water, whey or casein. Results of the study found that the ingestion of whey or casein immediately after one bout of heavy resistance exercise elicited a similar anabolic response in the subsequent one- to six-hour period. Here is a list of interesting findings, despite the similar increases in anabolic signaling over the six-hour period:

            • There were similar increases in total net anabolic signaling, despite whey and casein having differences in circulating insulin and amino acid supplements throughout the six hours, post-intervention. Whey protein ingestion resulted in a higher insulin spike than casein. Whey protein resulted in a higher rise in leucine and isoleucine. Furthermore, the sum of essential amino acids and amino acid concentrations were higher after whey protein supplementation, whereas casein resulted in higher concentrations of valine, arginine, the sum of essential amino acids, and the sum of amino acids at time points after the initial whey-induced peak.

            • As expected, whey protein resulted in an increase in protein synthesis, whereas casein showed a moderate but prolonged increase later. So in sum, a combination protein like whey and casein seems to be the optimal protein combo after training— as whey stimulates protein synthesis early, whereas casein stimulates a longer and more sustained increase in protein synthesis. A product like Optimum Nutrition’s NitroCore 24 has a blend of both whey and casein for optimal anabolic needs after training.

Reference:

            Reitelseder S, Agergaard J, Doessing S, Helmark IC, Lund P, Kristensen NB, Frystyk JF, Flyvbjerg A, Schjerling P, van Hall G, Kjaer M, Holm L. Whey and casein labeled with L-[1-13C] leucine and muscle protein synthesis: Effect of resistance exercise and protein ingestion. Am J Physiol Endocrinol Metab, 2010 Nov 2.