ABSTRACT: THIS ARTICLE REVIEWS THE AVAILABLE LITERATURE ON WHICH PROTEINS, AMINO ACIDS, OR COMBINATION OF BOTH SEEM TO BE OPTIMAL TO ENHANCE HYPERTROPHY AFTER RESISTANCE EXERCISE IN YOUNG ADULTS. DEPENDING ON THE CONTENT OF ESSENTIAL AMINO ACIDS AND PARTICULARLY LEUCINE, EITHER AN IMMEDIATE INGESTION OF ∼20 G MILK PROTEIN FOLLOWED BY A SIMILAR AMOUNT ∼1 HOUR LATER, OR A SINGLE BOLUS OF ∼40 G SEEMS TO BE SUITABLE. GREATER AMOUNTS MIGHT BE NECESSARY IF A PROTEIN OF LOWER QUALITY IS CHOSEN (I.E., PLANT-BASED PROTEINS) TO MATCH THE REQUIRED AMINO ACID QUANTITIES AND FACILITATE MUSCLE GROWTH.
Alex’s Notes: Larger muscles are stronger muscles, and muscle tissue is metabolic currency. In order to grow and develop your skeletal muscle, there must be a positive net protein balance (i.e. muscle protein synthesis exceeds muscle protein breakdown). A crucial element here is the availability of amino acids, especially the essential amino acids, and notably the branched-chained amino acid leucine. This review simply looks to overview the effects of different dietary proteins ingested immediately before, during, or after resistance training.
12 studies were included in the review that administered a single protein source in a timeframe of 90 minutes before, during, or after resistance training. Moreover, the study subjects were less than 40 years old and free from any diseases.
Seven studies analyzed milk-based proteins with four comparing them to soy protein. Unsurprisingly, a combination of milk proteins as is naturally occurring in milk was shown to be superior to soy protein in promoting hypertrophic gains in young health adults. It was also shown that whey protein seems to facilitate the hypertrophic gains more than casein in the early post-workout period, but that casein had a more prolonged effect on muscle protein synthesis. This makes sense in light of their digestion kinetics; whey protein is absorbed rapidly and spikes blood amino acid levels while casein forms globs in the stomach that make it take forever to digest and absorb.
The other studies looked at administration of amino acids with or without an additional protein source. Hopefully you didn’t just buy some BCAAs because adding additional amino acids to a sufficient amount of whey protein is pointless, and taking the amino acids by themselves is even worse.
Now here is the most important part. Overall daily protein and calorie intake are more important than a serving of protein around the training period. This isn’t say you shouldn’t supplement with protein. Quite contrary, a recent meta-analysis has shown that improvements in lean body mass favor protein supplementation independent of training experience or age. What is means is that muscle protein synthesis lasts longer than the 90 minutes following training and that overall diet is of paramount importance. With regard to supplementation, it appears that 20-25 grams of a combination of milk proteins (whey and casein) is ideal, with another meal 1-2 hours later. If you can’t eat again then increase the post-training intake to 40 grams of protein with half coming from casein for its slow digestive properties. And if for whatever reason you don’t do dairy, then make sure your protein supplies 3 grams of leucine, whatever amount that may be.