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Tom M. McLellan and Doug G. Bell

This study examined whether the prior consumption of coffee (COF) decreased the ergogenic effect of the subsequent ingestion of anhydrous caffeine (CAF). Thirteen subjects performed 6 rides to exhaustion at 80% VO2max 1.5 h after ingesting combinations of COF, decaffeinated coffee (DECOF), CAF, or placebo. The conditions were DECOF + placebo (A), DECOF + CAF (5 mg/kg) (B), COF (1.1 mg/kg caffeine) + CAF (5 mg/kg) (C), COF + CAF (3 mg/kg) (D), COF + CAF (7 mg/kg) (E), and colored water + CAF (5 mg/kg) (F). Times to exhaustion were significantly greater for all trials with CAF versus placebo (trial A). Exercise times (in minutes) were: 21.7 ± 8.1, 29.0 ± 7.4, 27.8 ± 10.8, 25.1 ± 7.9, 26.4 ± 8.0 and 26.8 ± 8.1 for trials A through F, respectively. In conclusion, the prior consumption of COF did not decrease the ergogenic effect of the subsequent ingestion of anhydrous CAF.

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Elizabeth Applegate

Athletes use a variety of nutritional ergogenic aids to enhance performance. Most nutritional aids can be categorized as a potential energy source, an anabolic enhancer, a cellular component, or a recovery aid. Studies have consistently shown that carbohydrates consumed immediately before or after exercise enhance performance by increasing glycogen stores and delaying fatigue. Protein and amino acid supplementation may serve an anabolic role by optimizing body composition crucial in strength-related sports. Dietary antioxidants, such as vitamins C and E and carotenes, may prevent oxidative stress that occurs with intense exercise. Performance during high-intensity exercise, such as sprinting, may be improved with short-term creatine loading, and high-effort exercise lasting 1-7 min may be improved through bicarbonate loading immediately prior to activity. Caffeine dosing before exercise delays fatigue and may enhance performance of high-intensity exercise.

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Kristin L. Jonvik, Jan-Willem van Dijk, Joan M.G. Senden, Luc J.C. van Loon and Lex B. Verdijk

Over the past decade, the use of dietary nitrate to enhance performance has received increased attention, with possible ergogenic effects being caused by the reduction of dietary nitrate into nitrite and nitric oxide ( Lundberg et al., 2008 ). Nitric oxide plays a key role in skeletal muscle

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Michael S. Bahrke, William P. Morgan and Aaron Stegner

Ginseng is one of the most popular herbal supplements in the world. Although it is used for the treatment and prevention of many ailments, it is also used to increase work efficiency and is purported to increase energy and physical stamina. Athletes use ginseng for its alleged performance-enhancing attributes. However, many studies examining the pharmacological effects of ginseng on physical performance have not employed sound scientific design and methodology. The purpose of this review is to provide an update on published empirical research focusing primarily on the efficacy of ginseng with respect to physical and athletic performance. Despite attempts in recent investigations to improve on the scientific rigor used in examining the ergogenic properties of ginseng, the authors conclude that many of the same methodological shortcomings observed in earlier studies persist. Enhanced physical performance after ginseng administration in well-designed investigations remains to be demonstrated.

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John Molphy, John W. Dickinson, Neil J. Chester, Mike Loosemore and Gregory Whyte

establishment of dosing thresholds for terbutaline; these dosing thresholds are extremely important given recent evidence of ergogenic effects of supratherapeutic dosages of inhaled terbutaline on sprint and power performance, muscle strength, and muscle hypertrophy, as well as inducing muscle phenotype

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Gail Butterfield

The desire to win leads physically active individuals to look for anything to improve performance. Many ergogenic aids are available; however, claims made about many of these products are not appropriate. To evaluate such products, one must consider the physiological sense of the claims, the supportive evidence provided, the research articles quoted, and the legal and health implications of use.

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Thomas B. Walker and Robert A. Robergs

Rhodiola rosea is an herb purported to possess adaptogenic and ergogenic properties and has recently been the subject of increased interest. The purpose of this article was to review and summarize recent investigations of the potential performance-enhancing properties of Rhodiola rosea. Such studies have generated equivocal results. Several investigations conducted in Eastern Europe have indicated that Rhodiola rosea ingestion may produce such positive effects as improved cognitive function and reduced mental fatigue. Other research from this region has illustrated enhanced endurance exercise performance in both humans and rats. Studies conducted in Western Europe and in North America have indicated that Rhodiola rosea may possess substantial antioxidant properties but have produced mixed results when attempting to demonstrate an ergogenic effect during exercise in humans.

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Andrew C. Morris, Ira Jacobs, Tom M. McLellan, Abbey Klugerman, Lawrence C.H. Wang and Jiri Zamecnik

The purpose of this study was to examine the effects of ginseng extract ingestion on physiological responses to intense exercise. Subjects performed a control ride (CN) on a cycle ergometer, followed by placebo (PL) and ginseng (GS) treatments. Ginseng was ingested as 8 or 16 mg/kg body weight daily for 7 days prior to trial GS. Venous blood was sampled for FFA, lactate, and glucose analyses. Due to similar findings for both dose groups, the subjects were considered as one group. Lactate, FFA, VO2, VE, and RPE increased significantly from 10 through 40 min. RER increased during the first 10 min of exercise and then remained stable, with no intertrial differences. Glucose did not vary significantly from 0 to 40 min or among treatments. RPE was significantly greater and time to exhaustion was significantly less during trial CN than PL or GS, while PL and GS trials were similar. The data indicated that with 1 week of pretreatment there is no ergogenic effect of ingesting the ginseng saponin extract.

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Nathan T. Jenkins, Jennifer L. Trilk, Arpit Singhal, Patrick J. O’Connor and Kirk J. Cureton

The purpose of this experiment was to learn whether low doses of caffeine have ergogenic, perceptual, and metabolic effects during cycling. To determine the effects of 1, 2, and 3 mg/kg caffeine on cycling performance, differentiated ratings of perceived exertion (D-RPE), quadriceps pain intensity, and metabolic responses to cycling exercise, 13 cyclists exercised on a stationary ergometer for 15 min at 80% VO2peak, then, after 4 min of active recovery, completed a 15-min performance ride 60 min after ingesting caffeine or placebo. Work done (kJ/kg) during the performance ride was used as a measure of performance. D-RPE, pain ratings, and expired-gas data were obtained every 3 min, and blood lactate concentrations were obtained at 15 and 30 min. Compared with placebo, caffeine doses of 2 and 3 mg/kg increased performance by 4% (95% CI: 1.0–6.8%, p = .02) and 3% (95% CI: –0.4% to 6.8%, p = .077), respectively. These effects were ergogenic, on average, but varied considerably in magnitude among individual cyclists. There were no effects of caffeine on D-RPE or pain throughout the cycling task. Selected metabolic variables were affected by caffeine, consistent with its known actions. The authors conclude that caffeine preparations of 2 and 3 mg/kg enhanced performance, but future work should aim to explain the considerable interindividual variability of the drug’s ergogenic properties.

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Paul L. Greenhaff

Phosphocreatine (PCr) availability is likely to limit performance in brief, high-power exercise because the depletion of PCr results in an inability to maintain adenosine triphosphate (ATP) resynthesis at the rate required. It is now known that the daily ingestion of four 5-g doses of creatine for 5 days will significantly increase intramuscular creatine and PCr concentrations prior to exercise and will facilitate PCr resynthesis during recovery from exercise, particularly in those individuals with relatively low creatine concentrations prior to feeding. As a consequence of creatine ingestion, work output during repeated bouts of high-power exercise has been increased under a variety of experimental conditions. The reduced accumulation of ammonia and hypoxanthine in plasma and the attenuation of muscle ATP degradation after creatine feeding suggest that the ergogenic effect of creatine is achieved by better maintaining ATP turnover during contraction.