Dojar Whereas it is clear that exogenous amino acids stimulate muscle protein synthesis at rest 16following resistance exercise and in association with a variety of clinical conditions including burn injury 19sarcopenia and cancer cachexia 22evidence regarding the ergogenic effects of supplementation with individual amino acids such as arginine are equivocal. During basal metabolism, NOS-dependent pathway is the major one for mitochondrial biogenesis, while, during physical exercise, NOS-independent via may play a role [ 31 ]. The ergogenic potential of this pathway has received considerable attention and has wide clinical applicability. In agreement with this, a stimulating effect of creatine on protein synthesis in animal cardiac and skeletal muscle in vitro has been found although there are also studies that do not confirm this 84 The three major forms of NO-producing supplementation include arginine, citrulline, and NO 3 — based supplementation. In meta-analyses of the effect of creatine on exercise performance, the conclusions are also somewhat variable Email alerts New issue alert. It is known that an L-Arginine infusion at rest increases plasma insulin, glucagon, growth hormone, prolactin and catecolamine concentrations [ 22 ].
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Metrics details Abstract Dietary supplements containing L-arginine, a semi-essential amino acid, are one of the latest ergogenic aids intended to enhance strength, power and muscle recovery associated with both aerobic and resistance exercise.
L-arginine is claimed to promote vasodilation by increasing nitric oxide NO production in the active muscle during exercise, improving strength, power and muscular recovery through increased substrate utilization and metabolite removal, such as lactate and ammonia. Research on L-arginine has recently tested this hypothesis, under the assumption that it may be the active compound associated with the vasodilator effects of NO. There were only five acute studies retrieved from the literature that evaluated exercise performance after L-arginine supplementation, three of which reported significant improvements.
Regarding studies on chronic effects, eight studies were encountered: four reported enhancements in exercise performance, whilst four reports showed no changes.
Whether these improvements in exercise performance — regardless of the aerobic or anaerobic nature of the exercise — can be associated with increases in NO production, has yet to be demonstrated in future studies. Low oral doses 20 g are well tolerated and clinical side effects are rare in healthy subjects. In summary, it is still premature to recommend dietary supplements containing L-arginine as an ergogenic aid for healthy physically active subjects.
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L-Arginine as a Potential Ergogenic Aidin Healthy Subjects
Brazuru L-Arginine as a potential ergogenic aid in healthy subjects. Dietary inorganic nitrate improves mitochondrial efficiency in humans. Sports Medicine42 2 As mentioned, many athletes use creatine in connection with resistance training as an aid to increase the training effect on muscle mass and strength. Like Arg-based supplements, Cit-based supplements are also NOS dependent; however, unlike Arg, Cit is not a substrate for arginase enzymes. December 30, Citation: Research on L-arginine has recently tested this hypothesis, under the assumption that it may be the active compound associated with the vasodilator effects of NO. Thus, under normal conditions arginine ingestion is not necessary for the stimulation of muscle protein synthesis by ingestion of EAAs. However, in healthy individuals, with normal NO production, L-Arginine supplementation seems to have little impact on aerobic exercise capacity, contrarily to individuals with reduced basal NO production [ 28 ].
Gur In contrast, mechanistic studies, arguing that nitrate alters muscle contractility and mitochondrial proteins, employed longer day supplementation periods. Journal of the Academy of Nutrition and Dietetics4 L-Arginine, a conditionally essential amino acid 2-aminoguanidinovaleric acid that serves functions of relevance to athletes, is the standard NO donor in supplementation and its typical dietary intake is nearly 3. Journal of Applied Physiology4 Some mechanistic studies have disclosed that NO 3 — may also reduce the ATP cost of muscle force production, as well as improve mitochondrial respiration efficiency [ 25 ]. European Journal of Applied Physiology, 5 Acute and chronic effects of dietary nitrate supplementation on blood pressure and the physiological responses to moderate-intensity and incremental exercise. Since an increased perfusion of muscle would be expected to narrow the concentration gradient between plasma and the intracellular fluid, one might therefore expect an increase in the rate of muscle blood flow in the basal state to accelerate the efflux of intracellular EAAs into plasma. The amount of amino-N deleted from the mixture as a result of dropping the nonessential amino acids NEAAs was not made up by changing the amount of the essential amino acids given.