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Amino Acids and Endurance Exercise

Mark Hargreaves and Rodney Snow

Although skeletal muscle is capable of oxidizing selected amino acids, exercise in the fed and carbohydrate-replete condition results in only a small increase in amino acid utilization. Nevertheless, it may be important to increase the dietary protein requirements of active individuals. There is ongoing debate as to whether the amino acids for oxidation are derived from the free amino acid pool, from net protein breakdown, or a combination of both. There has been interest in the potential ergogenic benefits of amino acid ingestion; however, BCAA ingestion does not appear to affect fatigue during prolonged exercise, there is little support from controlled studies to recommend glutamine ingestion for enhanced immune function, and although glutamine stimulates muscle glycogen synthesis, its addition to carbohydrate supplements provides no additional benefit over ingestion of carbohydrate alone.

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Amino Acid-Based Beverage Interventions Ameliorate Exercise-Induced Gastrointestinal Syndrome in Response to Exertional-Heat Stress: The Heat Exertion Amino Acid Technology (HEAAT) Study

Ricardo J.S. Costa, Kayla Henningsen, Stephanie K. Gaskell, Rebekah Alcock, Alice Mika, Christopher Rauch, Samuel N. Cheuvront, Phil Blazy, and Robert Kenefick

with whey protein hydrolysate promoting a greater gastric load ( Snipe et al., 2017 ). Whether these beneficial effects were due to the whole protein energy content or the presenting amino acid mixture affecting villi microvascular perfusion, cell stability, and/or function is unclear. The acute intake

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The Physiological Mechanisms of Effect of Vitamins and Amino Acids on Tendon and Muscle Healing: A Systematic Review

Christopher Tack, Faye Shorthouse, and Lindsy Kass

 al., 2001 ). Other supplements, such as olive oil, can reduce oxidative damage during healing ( Rosa et al., 2014 ), whereas the amino acid arginine can improve wound angiogenesis ( Raynaud-Simon et al., 2012 ). The choice of supplement is therefore critical. Additionally, there is evidence of negative

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The Postprandial Plasma Amino Acid Response Does Not Differ Following the Ingestion of a Solid Versus a Liquid Milk Protein Product in Healthy Adult Females

Glenn A.A. van Lieshout, Jorn Trommelen, Jean Nyakayiru, Janneau van Kranenburg, Joan M. Senden, Lex B. Verdijk, and Luc J.C. van Loon

response to exercise training ( Cermak et al., 2012 ). The muscle protein synthetic response to protein ingestion is attributed to the postprandial increase in circulating plasma amino acid (AA) concentrations, with leucine being of particular relevance ( Devries et al., 2018 ; Katsanos et al., 2006

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Isolated Leucine and Branched-Chain Amino Acid Supplementation for Enhancing Muscular Strength and Hypertrophy: A Narrative Review

Daniel L. Plotkin, Kenneth Delcastillo, Derrick W. Van Every, Kevin D. Tipton, Alan A. Aragon, and Brad J. Schoenfeld

Of the 20 amino acids recognized to compose the building blocks of human protein, only three possess a branched side chain: leucine, isoleucine, and valine. Numerous supplements are sold consisting of these three amino acids, collectively known as the branched-chain amino acids (BCAA), with claims

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Co-Ingestion of Branched-Chain Amino Acids and Carbohydrate Stimulates Myofibrillar Protein Synthesis Following Resistance Exercise in Trained Young Men

Sarah R. Jackman, Gareth A. Wallis, Jinglei Yu, Andrew Philp, Keith Baar, Kevin D. Tipton, and Oliver C. Witard

Nutritional modulation of the muscle anabolic response to exercise is underpinned by changes in muscle protein turnover at the metabolic level ( Tipton & Wolfe, 2001 ). Ingesting an amino acid source following resistance exercise stimulates muscle protein synthesis (MPS), leading to a positive net

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The Effects of Leucine-Enriched Branched-Chain Amino Acid Supplementation on Recovery After High-Intensity Resistance Exercise

Adam D. Osmond, Dean J. Directo, Marcus L. Elam, Gabriela Juache, Vince C. Kreipke, Desiree E. Saralegui, Robert Wildman, Michael Wong, and Edward Jo

, and active rest, have been widely implemented by athletes and exercising individuals. Several prior investigations support the use of supplementary branched-chain amino acids (BCAA) as a nutritional countermeasure to EIMD or related symptoms. When compared with nutritive (eg, carbohydrate) and

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Effects of Amino Acid Supplementation on Muscle Soreness and Damage

Kazunori Nosaka, P.▀ Sacco, and K.▀ Mawatari

This study investigated the effect of a supplement containing 9 essential and 3 non-essential amino acids on muscle soreness and damage by comparing two endurance exercise bouts of the elbow fexors with amino acid or placebo supplementation in a double blind crossover design. The supplement was ingested 30 min before (10 h post-fasting) and immediately after exercise (Experiment 1), or 30 min before (2-3 h after breakfast), immediately post, and 8 more occasions over 4-day post-exercise (Experiment 2). Changes in muscle soreness and indicators of muscle damage for 4 days following exercise were compared between supplement conditions using two-way ANOVA. No significant differences between conditions were evident for Experiment 1; however, plasma creatine kinase, aldolase, myoglobin, and muscle soreness were significantly lower for the amino acid versus placebo condition in Experiment 2. These results suggest that amino acid supplementation attenuates DOMS and muscle damage when ingested in recovery days.

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Absorption Kinetics of Amino Acids, Peptides, and Intact Proteins

Gabriella A.M. Ten Have, Marielle P.K.J. Engelen, Yvette C. Luiking, and Nicolaas E.P. Deutz

The small intestine acts as interface and regulator between the gut lumen and the rest of the body and controls the degree and rate of transport of amino acids coming from dietary protein via the portal vein to the liver and the systemic circulation. To measure protein absorption, kinetics multicatheter animal (pig) models in combination with amino acid tracer technology are available. Dietary factors infuence the absorption rates from the lumen to the gut, metabolism of dietary component in the gut, and the release of amino acids to the portal circulation from digested protein. In a balanced-protein meal, the gut dietary amino acid utilization (30–50%) for gut protein synthesis will result in a labile protein pool in the gut that can be benefcial during the postabsorptive state. To enhance gut retention, amount and quality of protein and the presence of carbohydrate are major factors. Besides this the use of a slowly digestible protein or the presence of fber in the meal can increase retention further. During the absorption of low-quality protein meals, fewer amino acids are utilized by the gut, resulting in higher amounts of amino acid release to the portal circulation. Malnutrition or starvation, protein depletion, defciencies of specifc nutrients, or illness such as sepsis all inhibit the growth and change protein turnover of the intestinal mucosa and therefore affect absorption kinetics. Therefore, the kind of protein meal that has the most optimal absorption kinetics (the most benefcial) for gut and for the rest of the body depends on these (patho)physiological circumstances. Despite the absence of different absorption kinetics between protein, peptides, and amino acids, they could be benefcial in specifc circumstances.

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Protein and Amino Acid Needs of the Strength Athlete

Peter W.R. Lemon

The debate regarding optimal protein/amino acid needs of strength athletes is an old one. Recent evidence indicates that actual requirements are higher than those of more sedentaty individuals, although this is not widely recognized. Some data even suggest that high protein/amino acid diets can enhance the development of muscle mass and strength when combined with heavy resistance exercise training. Novices may have higher needs than experienced strength athletes, and substantial interindividual variability exists. Perhaps the most important single factor determining absolute protein/amino acid need is the adequacy of energy intake. Present data indicate that strength athletes should consume approximately 12-15% of their daily total energy intake as protein, or about 1.5-2.0 g protein/ kg 1 (approximately 188-250% of the U.S. recommended dietary allowance). Although routinely consumed by many strength athletes, higher protein intakes have not been shown to be consistency effective and may even be associated with some health risks.