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Is Coffee a Useful Source of Caffeine Preexercise?
Pickering, C, Grgic, J
International journal of sport nutrition and exercise metabolism. 2020;(1):69-82
Abstract
Caffeine is a well-established ergogenic aid, with its performance-enhancing effects demonstrated across a wide variety of exercise modalities. Athletes tend to frequently consume caffeine as a performance enhancement method in training and competition. There are a number of methods available as a means of consuming caffeine around exercise, including caffeine anhydrous, sports drinks, caffeine carbohydrate gels, and gum. One popular method of caffeine ingestion in nonathletes is coffee, with some evidence suggesting it is also utilized by athletes. In this article, we discuss the research pertaining to the use of coffee as an ergogenic aid, exploring (a) whether caffeinated coffee is ergogenic, (b) whether dose-matched caffeinated coffee provides a performance benefit similar in magnitude to caffeine anhydrous, and (c) whether decaffeinated coffee consumption affects the ergogenic effects of a subsequent isolated caffeine dose. There is limited evidence that caffeinated coffee has the potential to offer ergogenic effects similar in magnitude to caffeine anhydrous; however, this requires further investigation. Coingestion of caffeine with decaffeinated coffee does not seem to limit the ergogenic effects of caffeine. Although caffeinated coffee is potentially ergogenic, its use as a preexercise caffeine ingestion method represents some practical hurdles to athletes, including the consumption of large volumes of liquid and difficulties in quantifying the exact caffeine dose, as differences in coffee type and brewing method may alter caffeine content. The use of caffeinated coffee around exercise has the potential to enhance performance, but athletes and coaches should be mindful of the practical limitations.
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2.
Effects of Dietary Supplements on Adaptations to Endurance Training.
Rothschild, JA, Bishop, DJ
Sports medicine (Auckland, N.Z.). 2020;(1):25-53
Abstract
Endurance training leads to a variety of adaptations at the cellular and systemic levels that serve to minimise disruptions in whole-body homeostasis caused by exercise. These adaptations are differentially affected by training volume, training intensity, and training status, as well as by nutritional choices that can enhance or impair the response to training. A variety of supplements have been studied in the context of acute performance enhancement, but the effects of continued supplementation concurrent to endurance training programs are less well characterised. For example, supplements such as sodium bicarbonate and beta-alanine can improve endurance performance and possibly training adaptations during endurance training by affecting buffering capacity and/or allowing an increased training intensity, while antioxidants such as vitamin C and vitamin E may impair training adaptations by blunting cellular signalling but appear to have little effect on performance outcomes. Additionally, limited data suggest the potential for dietary nitrate (in the form of beetroot juice), creatine, and possibly caffeine, to further enhance endurance training adaptation. Therefore, the objective of this review is to examine the impact of dietary supplements on metabolic and physiological adaptations to endurance training.
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3.
Infographic. Wake up and smell the coffee: caffeine supplementation and exercise performance.
Grgic, J, Grgic, I, Pickering, C, Schoenfeld, BJ, Bishop, DJ, Virgile, A, Pedisic, Z
British journal of sports medicine. 2020;(5):304-305
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4.
Anabolic and lipolytic actions of beta2 -agonists in humans and antidoping challenges.
Hostrup, M, Jacobson, GA, Jessen, S, Lemminger, AK
Drug testing and analysis. 2020;(5):597-609
Abstract
Inhaled beta2 -adrenoceptor agonists (beta2 -agonists) are among the most used substances in competitive sports. The 2020 Prohibited List issued by the World Anti-Doping Agency restricts use of all selective and non-selective beta2 -agonists in- and out- of competition with few exemptions. Formoterol, salbutamol, and salmeterol are allowed by inhalation within defined dosing limits. These restrictions are in place because supratherapeutic use of beta2 -agonist has the potential to be anabolic and to enhance performance, as well as due to potential side effects. Despite substantial documentation that beta2 -agonists exert anabolic and lipolytic actions, these actions are not widely recognized. Furthermore, a common misconception is that the inhaled route does not exert these effects. However, given the high relative systemic bioavailability via the inhaled route, inhalation at high doses can also exert anabolic and lipolytic actions. In this review, we highlight the anabolic and lipolytic actions beta2 -agonists can exert, regardless of the type of beta2 -agonist and the route of administration. The doses needed to provide such effects are also associated with adverse effects and would in most cases be detected in routine doping control. Notwithstanding, the beta2 -agonist regulations are associated with some challenges and given their ability to induce muscle growth and to enhance performance, it is important to continue developing effective detection strategies to prevent potential misuse of beta2 -agonists while allowing treatment of asthmatic subjects without causing adverse side effects or ergogenic actions.
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5.
Potential benefits of dietary nitrate ingestion in healthy and clinical populations: A brief review.
McDonagh, STJ, Wylie, LJ, Thompson, C, Vanhatalo, A, Jones, AM
European journal of sport science. 2019;(1):15-29
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Abstract
This article provides an overview of the current literature relating to the efficacy of dietary nitrate (NO3-) ingestion in altering aspects of cardiovascular and metabolic health and exercise capacity in healthy and diseased individuals. The consumption of NO3--rich vegetables, such as spinach and beetroot, have been variously shown to promote nitric oxide bioavailability, reduce systemic blood pressure, enhance tissue blood flow, modulate muscle O2 utilisation and improve exercise tolerance both in normoxia and in hypoxia, as is commonly observed in a number of disease states. NO3- ingestion may, therefore, act as a natural means for augmenting performance and attenuating complications associated with limited O2 availability or transport, hypertension and the metabolic syndrome. Recent studies indicate that dietary NO3- might also augment intrinsic skeletal muscle contractility and improve the speed and power of muscle contraction. Moreover, several investigations suggest that NO3- supplementation may improve aspects of cognitive performance both at rest and during exercise. Collectively, these observations position NO3- as more than a putative ergogenic aid and suggest that increasing natural dietary NO3- intake may act as a prophylactic in countering the predations of senescence and certain cardiovascular-metabolic diseases.
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Effects of dietary sports supplements on metabolite accumulation, vasodilation and cellular swelling in relation to muscle hypertrophy: A focus on "secondary" physiological determinants.
Cholewa, J, Trexler, E, Lima-Soares, F, de Araújo Pessôa, K, Sousa-Silva, R, Santos, AM, Zhi, X, Nicastro, H, Cabido, CET, de Freitas, MC, et al
Nutrition (Burbank, Los Angeles County, Calif.). 2019;:241-251
Abstract
Increased blood flow via vasodilation, metabolite production, and venous pooling contribute to the hyperemia and cellular swelling experienced during resistance training. It has been suggested that these effects play a role in hypertrophic adaptations. Over the past 2 decades, sport supplement products have been marketed to promote exercise hyperemia and intracellular fluid storage, thereby enhancing hypertrophy via acute swelling of myocytes. The three main classes of supplements hypothesized to promote exercise-induced hyperemia include vasodilators, such as nitric oxide precursor supplements; anaerobic energy system ergogenic aids that increase metabolite production, such as β-alanine and creatine; and organic osmolytes, such as creatine and betaine. Previous studies indicated that these dietary supplements are able to improve muscle performance and thus enhance muscle hypertrophy; however, recent evidences also point to these three classes of supplements affecting "secondary" physiological determinants of muscle mass accretion such as vasodilation, metabolite accumulation, and muscle cellular swelling. Although we recognize that the literature is relatively scarce regarding these topics, a better comprehension and discussion of these determinants can lead to increased knowledge and might guide further research regarding the proposed mechanisms of action of the identified compounds. In this case, increased knowledge may contribute to the development of improved efficacy, new products, or direct new research to specifically investigate those secondary effects. The aim of this review was to bring into focus new perspectives associated with secondary physiological effects induced by supplementation and to determine their relevance.
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Are low doses of caffeine as ergogenic as higher doses? A critical review highlighting the need for comparison with current best practice in caffeine research.
Pickering, C, Kiely, J
Nutrition (Burbank, Los Angeles County, Calif.). 2019;:110535
Abstract
Caffeine is a popular and widely consumed sporting ergogenic aid. Over the years, the effects of different caffeine doses have been researched, with the general consensus being that 3 to 6 mg/kg of caffeine represents the optimal dose for most people. Recently, there has been increased attention placed on lower (≤3 mg/kg) caffeine doses, with some research suggesting these doses are also ergogenic. However, a critical consideration for athletes is not merely whether caffeine is ergogenic at a given dose, but whether the consumed dose provides an optimized performance benefit. Following this logic, the aim of this review was to identify a potential oversight in the current research relating to the efficacy of lower caffeine doses. Although low caffeine doses do appear to bestow ergogenic effects, these effects have not been adequately compared with the currently accepted best practice dose of 3 to 6 mg/kg. This methodological oversight limits the practical conclusions we can extract from the research into the efficacy of lower doses of caffeine, as the relative ergogenic benefits between low and recommended doses remains unclear. Here, we examine existing research with a critical eye, and provide recommendations both for those looking to use caffeine to enhance their performance, and those conducting research into caffeine and sport.
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8.
Timing of ergogenic aids and micronutrients on muscle and exercise performance.
Stecker, RA, Harty, PS, Jagim, AR, Candow, DG, Kerksick, CM
Journal of the International Society of Sports Nutrition. 2019;(1):37
Abstract
The timing of macronutrient ingestion in relation to exercise is a purported strategy to augment muscle accretion, muscle and athletic performance, and recovery. To date, the majority of macronutrient nutrient timing research has focused on carbohydrate and protein intake. However, emerging research suggests that the strategic ingestion of various ergogenic aids and micronutrients may also have beneficial effects. Therefore, the purpose of this narrative review is to critically evaluate and summarize the available literature examining the timing of ergogenic aids (caffeine, creatine, nitrates, sodium bicarbonate, beta-alanine) and micronutrients (iron, calcium) on muscle adaptations and exercise performance. In summary, preliminary data is available to indicate the timing of caffeine, nitrates, and creatine monohydrate may impact outcomes such as exercise performance, strength gains and other exercise training adaptations. Furthermore, data is available to suggest that timing the administration of beta-alanine and sodium bicarbonate may help to minimize known untoward adverse events while maintaining potential ergogenic outcomes. Finally, limited data indicates that timed ingestion of calcium and iron may help with the uptake and metabolism of these nutrients. While encouraging, much more research is needed to better understand how timed administration of these nutrients and others may impact performance, health, or other exercise training outcomes.
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9.
Beyond muscle: the effects of creatine supplementation on brain creatine, cognitive processing, and traumatic brain injury.
Dolan, E, Gualano, B, Rawson, ES
European journal of sport science. 2019;(1):1-14
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Abstract
The ergogenic and therapeutic effects of increasing muscle creatine by supplementation are well-recognized. It appears that similar benefits to brain function and cognitive processing may also be achieved with creatine supplementation, however research in this area is more limited, and important knowledge gaps remain. The purpose of this review is to provide a comprehensive overview of the current state of knowledge about the influence of creatine supplementation on brain function in healthy individuals. It appears that brain creatine is responsive to supplementation, however higher, or more prolonged dosing strategies than those typically used to increase muscle creatine, may be required to elicit an increase in brain creatine. The optimal dosing strategy to induce this response, is currently unknown, and there is an urgent need for studies investigating this. When considering the influence of supplementation strategies on cognitive processes, it appears that creatine is most likely to exert an influence in situations whereby cognitive processes are stressed, e.g. during sleep deprivation, experimental hypoxia, or during the performance of more complex, and thus more cognitively demanding tasks. Evidence exists indicating that increased brain creatine may be effective at reducing the severity of, or enhancing recovery from mild traumatic brain injury, however, only limited data in humans are available to verify this hypothesis, thus representing an exciting area for further research.
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10.
Carnosine in health and disease.
Artioli, GG, Sale, C, Jones, RL
European journal of sport science. 2019;(1):30-39
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Abstract
Carnosine was originally discovered in skeletal muscle, where it exists in larger amounts than in other tissues. The majority of research into the physiological roles of carnosine have been conducted on skeletal muscle. Given this and the potential for muscle carnosine content to be increased with supplementation, there is now a large body of research examining the ergogenic effects (or otherwise) of carnosine. More recent research, however, points towards a potential for carnosine to exert a wider range of physiological effects in other tissues, including the brain, heart, pancreas, kidney and cancer cells. Taken together, this is suggestive of a potential for carnosine to have therapeutic benefits in health and disease, although this is by no means without complication. Herein, we will provide a review of the current literature relating to the potential therapeutic effects of carnosine in health and disease.