Protein 101

It has long been debated about how much protein a person needs on a daily basis. The dietary reference intake, which was created by the Food and Nutrition Board, Institute of Medicine, and National Academies for use when evaluating and planning diets for healthy individuals, is 0.8g/kg (.35g/lb of body weight). While this may be enough for the average person, doing minimal physical work, it does not provide the amino acid content needed to help maintain and repair damaged muscle tissue. It has been shown repeatedly in scientific studies that a protein intake of 1.0-1.7g/kg (.45-.77g/lb of body weight) per day may be needed for athletes. Even higher protein intakes (>2g/kg of body weight) have been studied, with no determinable increases in protein synthesis found past 1.7g/kg. The need for more protein is due to the increase in metabolic and physical stress the body sees as activity and intensity are increased. Higher protein diets have been shown to increase anabolic hormone activity and protein synthesis in muscle tissue for up to 48 hours after training. These two factors will greatly reduce recovery time and increase the quality of the recovery period, allowing your next training session to be sustained longer and stronger. There is some evidence that suggests that an intake of 24-48g immediately following a workout can even further these effects. Although the conclusions for post-workout protein are mixed, one thing that is almost certain is total daily protein intake of at least 1g/kg for aerobic training and 1.4g/kg for weight training is vital for anyone who is active regularly, regardless of skill or ability.

Determining how you should get this protein can also be challenging and unfortunately, not all proteins are created equally. There are two types of proteins: complete and incomplete. Complete proteins contain all 8 essential amino acids, meaning that when metabolized, these proteins contain all the amino acids the body cannot produce on its own. There are a few amino acids that are considered conditionally essential, however, they are not included in the 8 that are considered essential. Sources of complete proteins are animal proteins, fish, dairy products, eggs, and soy. Now, three of these essential amino acids have been studied in great depth with regard to their effect on muscle protein synthesis: Leucine, Isoleucine, and Valine. In studies, when taken at a 2:1:1 (leucine: isoleucine: valine) ratio, these branched-chain amino acids (BCAA) have been shown to reduce muscle protein breakdown and increase muscle protein synthesis, effectively increasing lean body mass at a higher rate than placebo groups. Taking these in concentrated form (powder, drink, etc) around workouts, or eating foods with high BCAA content such as beef can improve your exercise performance at any level. Whey protein is by far the most popular powdered protein supplement to hit the supplement market, and rightfully so. It is a complete, fast-digesting protein, which means that all of the amino acids your body needs are available on-demand. Unlike solid food protein which has long-chained proteins that metabolize more slowly, whey protein is a short-chain protein that metabolizes quickly, which is useful during or after periods of activity to help recover. Whey protein is one of two products produced from concentrated milk protein; the other is casein. This very long chain, slow digesting protein is great for use in a meal replacement smoothie to help keep you feeling more full over a longer period of time. Plant proteins such as soy, pea, and hemp have been concentrated and are also sold in powdered form. Peas and hemp are both incomplete, so it is important to check the amino acid profiles and add other proteins to your diet that will contain the missing amino acids. Because the synergistic effects of amino acids are not fully understood, what the ideal amino acid profile looks like is impossible to determine, but what is important is getting all 8 essential amino acids, with a high BCAA content.