Protein plays a large role in our body by building new muscle tissue, influencing neurotransmitters, upholding the structure and integrity of our cells as well as influencing energy metabolism and immune function.
The protein requirements for adults begin at 0.8gm/kg but the demands for an athlete are higher than those who are sedentary. Amounts safely researched vary from 1.2gm/kg-3gm/kg with higher amounts favoring weightlifters and body builders. Muscle accounts for about 40% of the protein within the human body. The more muscle, the more protein needed. Makes sense.
Protein is composed of smaller building blocks called Amino Acids (AA) of which there are 20. Nine of these AA are considered essential, meaning we must get them from food sources like meat, dairy, nuts, seeds, and legumes.
Tryptophan, Valine, Threonine, Isoleucine, Leucine, Lycine, Phenylalanine, Methionine, Histadine.
Our body uses those 9 EAA to synthesize the remaining 11. A protein is considered complete when it contains all 9 essential amino acids. Sources of protein include whole foods, protein supplements, solutions of protein hydrolysates, and free amino acids (1).
Meat and dairy are complete proteins while soy is the most complete plant-based protein; limited only by methionine. Consumption of amino acids as peptides and dipeptides result in faster absorption into the blood stream compared to the ingestion of whole proteins or single amino acids (1).
Amazon prime has a significant protein powder inventory varying from non-essential amino acids like arginine and glutamine, to complete sources like Whey or collagen, BCAA, and EAA. What’s an online shopper to do?
Arginine and glutamine are 2 popular amino acids and for good reason. AA are transmitted in muscle to their respective keto acids and are utilized for gluconeogenesis within the liver. Arginine ingestion promotes secretion of hormones that facilitate the removal of ammonia through the urea cycle (1). This is a good thing. No one wants a buildup of acidic ammonia in their body. In slow twitch muscle there’s a demand for glutamine 3x higher than fast twitch muscle suggesting a greater demand for glutamine during endurance training. Although the body makes glutamine, in times of extreme duress or exercise it is considered “conditionally essential” and additional exogenous sources are needed. Training for a marathon certainly is a condition that meets that criteria.
Of the 9 essential AA, three of them are branched; like a large oak tree with wide branches compared to a palm tree with a single stem. The three BCAA are Leucine, Isoleucine, and Valine. These three amino acids account for 15% of all amino acids in the human body. This means if a person eats 100 grams of protein a day, 15 grams will be these 3 BCAAs.
An extensive lit review by Gleeson, M. examined the efficacy of EAA/BCAA supplementation on several aspects of its role in athletic performance with positive results.
Male students aged 19-21 years engaged in 1 week of intensive exercise training including isometric exercises and elbow extensions with a 10 day recovery period and repeated this process twice. After exercise, participants were given an amino acid mixture containing all EAA (and BCAA) totaling 5.6gm or a placebo. The EAA group experienced a smaller decline in strength of elbow and isometric strength after 2 days of intense training. The AA mixture accelerated the rate of elbow extensor muscle recovery and produced higher muscle strength throughout the recovery period. Most subjects reported less delayed muscle soreness when given the AA mixture (2).
While the first study displayed positive effects of supplementing post work out with amino acids, the next study of the review examined specific amounts.
13 college athletes engaged in sustained exercise for 2-3 hours a day, 5 days a week for 6 months. During the 6-month intervention, subjects received treatments of an AA oral mix of either 2.2gm, 4.4gm, or 6.6g a day. The 2.2gm group showed no significant markers on blood measures. The 4.4gm group had significant increase in serum albumin and reduction in blood lactic acid. The 6.6gm group produced the most notable changes of reduced elevation of serum CPK (an indicator of muscle inflammation) as well an increase of hemoglobin (15.2-15.8) and hematocrit (44.9-46.8) suggesting improved oxygen handling capacity. The highest amino acid supplement had the greatest positive significant results (2).
The final study of this lit review examined the effects of administering a greater amount of AA mixture, 7.2gm daily, to 23 elite rugby players for three months during a course of intense physical training. The athletes maintained a regular training schedule, and none had previously taken AA supplementation prior to the study. Blood was collected at the end of the 3-month intervention and revealed an increase in hematocrit, hemoglobin, and iron aligning with the results of the previous study; suggesting an increased oxygen handling capacity. This increase in red blood cell production suggests the potential for AA supplementation in higher amounts potentially enhancing the capacity of the blood to carry oxygen to cells and reducing lactic acid in the blood which can improve recovery.
Overall the results of the studies in this lit review consistently displayed supportive evidence that AA supplementation had positive effects on muscle integrity, recovery, and possible enhancement of oxygen carrying capacity of blood cells improving performance.
The research suggests that Amino Acid supplementation, and more specifically Essential Amino Acid supplementation have a positive influence on performance and recovery. Is there anything that could make this better? Cake is better with a glass of milk, burgers are better with melted cheese, and protein is better with carbs. The co-ingestion of protein with carbohydrates stimulates muscle synthesis and optimizes whole body protein balance when compared with intake of protein or carbohydrate alone (1).
The primary goal of traditional post work out nutrient timing is to replenish lost glycogen stores. Replenishing glycogen stores with a rapidly absorbed form of carbohydrates (such as highly branched cyclic dextrin) when consumed immediately post exercise can replenish the rate of glycogen re-synthesis by as much as 50% when compared to ingesting carbohydrates 2 hours after exercise. Adding protein to a post work out carbohydrate meal can further enhance glycogen re-synthesis. The presence of insulin after carbohydrate ingestion helps transport amino acids to be delivered to muscle cells for repair.
Muscle protein breakdown is slightly elevated immediately post exercise and then rises shortly thereafter. As the above studies show, supplementing with AA and BCAA help improve muscle recovery. Consuming a protein/carbohydrate combination supplement within this immediate window post exercise not only replenishes glycogen stores but the presence of insulin assists with transporting AA to muscle cells, simultaneously preventing degradation through proteolysis and enhancing the effect of synthesizing new muscle tissue. A study by Levenhagen et al found that consuming an oral supplement of 10P/8C/3F immediately following exercise showed a threefold increase of protein synthesis in legs compared to just 12% three hours post work out (3).
Esmarck et al’s research displayed evidence that consuming protein immediately after training enhanced muscular growth compared to delayed protein intake. Additional studies included in this extensive lit review found that a protein/carb combination suggest a post exercise window and “delaying post work out nutrient intake may impede muscular gains”. Increase in lean body mass, positive muscular adaptations, increased muscle synthesis with the greatest affects seen in those already in shape. Makes sense why the tank top guy takes his post work out drink so seriously, while the Zumba crew bring their water and dance moves.
In practical application, “High quality protein dosed at 0.4-0.5gm/kg of LBM at both pre and post exercise is a simple, relatively fail safe general guideline that reflect the current evidence showing a maximal acute anabolic effect of 20-40gm…Pre and post exercise meals should not be separated by more than approximately 3-4hrs given a typical resistance training bout lasting 45-90minutes.” (3)
If it isn’t possible to bring a chicken breast and side of rice to the gym, a protein shake with some carbs will do just fine. With an online inventory enough to make your head spin, know this: any complete protein supplement powder will contain all EAA and subsequently all BCAA. As will a turkey sandwich. Now you know your options for optimizing your work outs is as easy as a click on amazon or just reaching in the fridge for some lunch meat.
originally written for nutrition coaching institute @ ncicertifications.com
- Gleeson M. Interrelationship between Physical Activity and Branched-Chain Amino Acids. The Journal of Nutrition. 2005;135(6)
- Ohtani M, Sugita M, Maruyama K. Amino Acid Mixture Improves Training Efficiency in Athletes. The Journal of Nutrition. 2006;136(2)
- Aragon A, Schoenfeld B. Nutrient Timing Revisited. Functional Foods. 2013:65-89.
originally written for nutrition coaching institute @ ncicertifications.com