Whey Protein & Exercise

     It has often been debated whether protein supplements are really beneficial in the muscle building process. Most people have heard of protein supplements such as whey, casein, and soy but do not know what exactly the supplements are made of and their benefits. Whey and casein are derived from dairy products. In cheese production, casein is the curd and whey is the liquid, watery portion that remains after the curd has been removed. Of the three supplements mentioned, whey and casein have the greatest effect on protein synthesis. Specifically, one research study indicated a 34% increase in muscle synthesis when milk products were consumed compared to soy products post-exercise. Furthermore, when comparing the exercise related benefits of whey and casein, whey has been shown to be superior. In digestion, casein is slow acting whereas whey is fast acting. This means that whey is absorbed faster which leads to a faster increase of amino acids in the blood. The amino acids stimulate and increase muscle synthesis. Whey is also a higher-quality protein and contains higher levels of branched-chain amino acids (BCAA).  Research also supports the beneficial effects whey can have on increasing muscle strength and lean body mass.
            It is recommended that runners and endurance athletes consume 1.2-1.5 g/kg of protein a day while body builders should consume 1.7 g/kg. An intake of 20-25 g of whey protein combined with a healthy diet is recommended for optimal benefits including muscle growth. Furthermore, whey protein isolate has been specifically shown to provide higher amounts of whey protein when compared to whey powders and concentrates. It has not been shown, however, if the whey protein isolate is superior to the other products.             Consuming whey protein and a carbohydrate source both pre and post-exercise provides the greatest benefit. In addition, a protein shake or smoothie containing whey protein should be consumed within 30-45 of exercising.             In conclusion, whey protein offers many exercise-related benefits. The benefits include an increase in muscle mass, an increase in muscle strength, and an increase in lean body mass. It should be consumed according to the recommended amount along with a healthy diet.

Tang JE, Moore DR, Kujbida GW, Tarnopolsky MA, Phillips SM. Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. J Appl Physiol. 2009; 107: 987-992. 
Cribb P, Hayes A. Effects of supplement timing and resistance exercise on skeletal muscle hypertrophy. MSSE. 2006; 38(11): 1918-1925. 

Stephanie Bailey- Dietetic Intern - University of Memphis

BIOMechaniks: Train the mind and the body will follow