Abstract
Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature on the safety and efficacy of the use of energy drinks (ED) or energy shots (ES). The ISSN has concluded the following. 1. Although ED and ES contain a number of nutrients that are purported to affect mental and/or physical performance, the primary ergogenic nutrients in most ED and ES appear to be carbohydrate and/or caffeine. 2. The ergogenic value of caffeine on mental and physical performance has been well-established but the potential additive benefits of other nutrients contained in ED and ES remains to be determined. 3. Consuming ED 10-60 minutes before exercise can improve mental focus, alertness, anaerobic performance, and/or endurance performance. 4. Many ED and ES contain numerous ingredients; these products in particular merit further study to demonstrate their safety and potential effects on physical and mental performance. 5. There is some limited evidence that consumption of low-calorie ED during training and/or weight loss trials may provide ergogenic benefit and/or promote a small amount of additional fat loss. However, ingestion of higher calorie ED may promote weight gain if the energy intake from consumption of ED is not carefully considered as part of the total daily energy intake. 6. Athletes should consider the impact of ingesting high glycemic load carbohydrates on metabolic health, blood glucose and insulin levels, as well as the effects of caffeine and other stimulants on motor skill performance. 7. Children and adolescents should only consider use of ED or ES with parental approval after consideration of the amount of carbohydrate, caffeine, and other nutrients contained in the ED or ES and a thorough understanding of the potential side effects. 8. Indiscriminant use of ED or ES, especially if more than one serving per day is consumed, may lead to adverse events and harmful side effects. 9. Diabetics and individuals with pre-existing cardiovascular, metabolic, hepatorenal, and neurologic disease who are taking medications that may be affected by high glycemic load foods, caffeine, and/or other stimulants should avoid use of ED and/or ES unless approved by their physician.
Bill Campbell, Colin Wilborn, Lem Taylor, Mike Greenwood, Stephen Schmitz, Rick Collins, Jose Antonio contributed equally to this work.
Copyright comment
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Introduction
According to published research, energy drinks (ED) are the most popular dietary supplement besides multivitamins in the American adolescent and young adult population [Citation1–Citation3]. ED are also reported to be the most popular supplement among British athletes [Citation4]. More recently, energy shots (ES) have also been purported to possess ergogenic value on mental focus and/or performance [Citation5]. It is important to make a distinction between ED, ES, and sports drinks. Sports drinks are a unique category within the beverage industry and are marketed to consumers with the primary function of promoting hydration, replacing electrolytes and sustaining endurance performance capacity. They typically provide a small amount of carbohydrate (e.g., 6-8 grams/100 ml) and electrolytes (sodium, potassium, calcium, magnesium). ED, on the other hand, typically contain higher amounts of carbohydrate along with nutrients purported to improve perceptions of attention and/or mental alertness. Low calorie ED are also marketed to increase mental alertness, energy metabolism, and performance. Energy shots are typically 2-4 oz. servings of concentrated fluid containing various purported ergogens. Since ED and ES contain carbohydrate, caffeine, and/or nutrients that may affect mental focus and concentration, they have the potential to affect exercise capacity and perceptions of energy and/or fatigue. The purpose of this position stand is to critically evaluate the scientific literature and make recommendations in regards to the role that ED and/or ES may have on exercise performance and energy expenditure/metabolism. Additionally, we will discuss safety considerations in regards to the use of ED and/or ES.
Methods
This analysis represents a systematic review of the literature on the effects of “energy drinks” on exercise and cognitive performance as well as primary ingredients contained in popular energy drinks. A comprehensive literature search was performed by searching the Medline database of the US National Library of Medicine of the National Institutes of Health. The search strategy involved entering “energy drinks” and commercial names of energy drinks and/or caffeinated beverages as well as a search of primary nutrients contained in popular energy drinks (e.g., caffeine, carbohydrate, taurine, glucoronolactone, Guarana, Yerba Mate, etc.). It is important to note, from a United States regulatory perspective, several of these ED are marketed as dietary supplements and not beverages, and the label on the product will indicate which category of Food and Drug Administration (FDA) authority the product falls under. Each category has its own set of governing laws and regulations. For example, depending on the category, the labels will include Supplement Facts (dietary supplements) or Nutrition Facts (beverages). A paper summarizing the literature related to ED was presented at the 2011 International Society of Sports Nutrition Annual meeting. Thereafter, a position stand writing team was organized to develop this paper. Drafts of this position stand were then reviewed by all authors as well as the Research Committee of the International Society of Sports Nutrition (ISSN). The final version of this paper was then adopted as the official position of the ISSN.
Ergogenic/performance considerations
The ingestion of nutrients prior to, during, and/or following exercise can affect exercise performance and/or training adaptations [Citation6]. ED typically contain water, carbohydrates (e.g., glucose, maltodextrin), vitamins, minerals, and “proprietary blends” of various nutrients purported to increase energy, alertness, metabolism, and/or performance (e.g., caffeine, taurine, amino acids, glucoronolactone, Guarana, Ginkgo biloba, Carnitine, Panax ginseng, Green Tea, Yerba Mate, etc.). Therefore, ingestion of ED or ES prior to, during, and/or following exercise could have some ergogenic value. Tables and present a list of ingredients found in several ED/ES marketed in the United States. The next section provides an overview of the potential ergogenic value of some of the most commonly found nutrients in ED/ES.
Caffeine
Caffeine is the most common ingredient utilized in energy drinks. Caffeine is extracted from the raw fruit of over sixty species of coffee plants (coffea Arabica), all part of the methylxanthine family. Caffeine is also extracted from tea, kola nuts, and cocoa. After ingestion, caffeine is quickly absorbed and increases in plasma concentrations are generally observed between 30 – 60 minutes following ingestion [Citation7]. The difference in absorption time is dependent on the physicochemical formulation properties of the product dose [Citation8]. Caffeine is a strong cardiovascular stimulant that increases epinephrine output to a greater extent when ingested via its anhydrous formulation when compared to an equal amount of brewed or instant caffeinated coffee [Citation9, Citation10]. In addition, caffeine’s half-life ranges from approximately 2 to 10 hours with 0.5% - 3.5% of its content excreted unchanged in urine and select amounts eliminated via perspiration [Citation11]. A recent position stand from the Journal of the International Society of Sports Nutrition [Citation7] summarized the effects of caffeine on exercise performance as follows:
Caffeine is effective for enhancing sport performance in trained athletes when consumed in low-to-moderate dosages (~3-6 mg·kgBM-1) and overall does not result in further enhancement in performance when consumed in higher dosages (≥ 9 mg·kgBM-1).
Caffeine exerts a greater ergogenic effect when consumed in an anhydrous state as compared to coffee.
It has been shown that caffeine can enhance vigilance during bouts of extended exhaustive exercise, as well as periods of sustained sleep deprivation.
Caffeine is ergogenic for sustained maximal endurance exercise, and has been shown to be highly effective for time-trial performance.
Caffeine supplementation is beneficial for high-intensity exercise, including team sports such as soccer and rugby, both of which are categorized by intermittent activity within a period of prolonged duration.
The literature is equivocal when considering the effects of caffeine supplementation on strength-power performance, and additional research in this area is warranted.
The scientific literature does not support caffeine-induced diuresis during exercise, or any harmful change in fluid balance that would negatively affect performance.
As demonstrated below, several studies have reported significant improvements in both aerobic and resistance exercise with a relative dosage of approximately 2 mg·kgBM-1of caffeine. This is less than the amount recommended (3-6 mg·kgBM-1) to enhance performance [Citation7], and may contribute to the hypothesis that the synergistic effects of the various ingredients contained in ED/ES are responsible for the reported improvements in exercise performance.
Carbohydrate
Another common ingredient in most ED is some type of carbohydrate source (e.g., glucose, sucrose, maltodextrin, etc.). Energy drinks also typically contain glucuronolactone, an ingredient which is involved in ascorbic acid synthesis and is metabolized into xylulose [Citation12]. Evidence from numerous studies indicates that carbohydrate feeding during exercise of about 45 minutes or longer can improve endurance capacity and performance [Citation13, Citation14]. Mechanisms by which carbohydrate feeding prior to and during exercise improves endurance performance include maintaining blood glucose levels, maintaining high levels of carbohydrate oxidation, and the sparing of liver and possibly skeletal muscle glycogen [Citation15]. Peak rates of carbohydrate oxidation are commonly around 1 g of carbohydrate per minute or 60 g·hr-1. Glucose, sucrose, maltodextrins and amylopectin are oxidized at high rates, while fructose, galactose and amylose are oxidized at lower rates (approximately 25-50% lower) [Citation16]. Consequently, sports drinks typically contain a mixture of various types of carbohydrates designed to optimize exogenous carbohydrate oxidation [Citation17].
ED’s contain approximately 25-30 grams of carbohydrate per 240 mL (8 fluid ounces) serving. This amount nearly meets the lower value of 30 grams/hour recommended during endurance exercise, but falls short of the upper range of 60 g·hr-1. In order to meet this upper level of 60 grams of carbohydrate per hour during endurance exercise, approximately 530 mL (18 fluid ounces) of a typical ED per hour would need to be consumed. While the total carbohydrate content of typical ED is quite high, a shortcoming exists in regards to the concentration of commercially available energy drinks. The American College of Sports Medicine [Citation18] and the ISSN [Citation6, Citation17] recommend ingesting carbohydrate in a 6-8% solution (6-8 grams per 100 ml of fluid) during endurance exercise. A typical ED provides carbohydrates at a greater concentration, typically around an 11-12% solution. Ingesting higher percentages (>10%) of carbohydrate in fluids has been reported to delay gastric emptying and increase gastrointestinal distress [Citation19, Citation20]. Consequently, athletes who want to use ED as sports drinks may need to dilute the beverage and/or alternate consumption of ED and water during exercise.
Other nutrients
Tables , , and present a list of additional nutrients commonly found in ED or ES. Most ED and ES also contain a small amount of vitamins (e.g., thiamin, riboflavin, niacin, Vitamin B6, Vitamin B12, pantothenic acid, Vitamin C) and electrolytes (e.g., sodium, potassium, phosphorus, etc.). While the addition of these nutrients may add to the nutrient density of these products, there is little evidence that ingestion of these vitamins and minerals in the amounts found in ED and ES would provide any ergogenic benefit during exercise performance in well-nourished individuals [Citation17, Citation18]. Additionally, ED and ES typically contain nutrients purported to promote cognition and mental focus (e.g., Taurine, Ginkgo biloba, L-Tyrosine, Citocoline, 5-Hydroxy-L-Tryptophan [5-HTP], St. John’s Wort, etc.), stimulants (e.g., caffeine, Guarana, Green Tea, Synephrine, Yerba mate, Yohimbine, Tyramine, Vinpocetine, etc.), and/or various purported ergogenic nutrients (e.g., Panax Ginseng, L-Carnitine, D-Ribose, β-Alanine, Inositol, Citrulline, Quercetin, etc.). While there are data to support the potential ergogenic value of some of these nutrients on cognitive function and/or exercise capacity [Citation17, Citation18]; the amounts found in ED and ES are generally much lower than the typical concentrations associated with an ergogenic effect. Consequently, it is unclear whether adding these nutrients to ED and/or ES provides a synergistic or additive effect to the carbohydrate and caffeine found in these products. In addition, adding these nutrients to the caffeine found in ED and/or ES may change the adverse effect profile of these finished products, and warrant further study.
Exercise performance
Several studies have investigated the effects of ED consumption prior to exercise. The types of exercise that were evaluated include resistance exercise [Citation167, Citation168], anaerobic exercise [Citation169], and aerobic/endurance exercise [Citation62, Citation170–Citation172].
Ingestion prior to anaerobic exercise
Many of the studies investigating the effects of ED ingestion on anaerobic performance measures have been conducted within the past several years. In a crossover study (separated by seven days), Forbes and colleagues [Citation168] gave 15 physically active college-aged students a commercially available energy drink standardized with 2 mg·kgBM-1of caffeine or an isoenergetic, isovolumetric, non-caffeinated placebo 60-minutes prior to exercise. The exercise consisted of three sets of 70% one repetition maximum (1RM) bench press conducted to failure on each set with one minute of rest between each set. Following the resistance exercise bout, three x 30-second Wingate Anaerobic Capacity tests were also conducted with two minutes of rest between each test. The ED significantly increased total bench press repetitions over three sets (approximately 6% more repetitions completed) but had no effect on Wingate peak or average power.
In a similarly designed study, a commercially available energy drink (providing an average of 2.1 mg of caffeine per kg of body mass) given to physically active male and female participants 45 minutes prior to exercise resulted in a significant increase in leg press total lifting volume (12% increase as compared to a carbohydrate placebo) but had no effect on bench press total lifting volume [Citation167] or multiple 20-second Wingate-type cycle sprints [Citation173]. Hoffman and colleagues [Citation169] gave male strength/power athletes an ED containing an average of 1.8 mg·kgBM-1of caffeine or a placebo beverage that was similar in taste and appearance but contained only inert substances. Following the ingestion of the ED, three separate 20-second Wingate tests separated by about 15 minutes were performed. Results revealed that there were no significant differences between trials in any anaerobic power measure. In a recent publication, 12 healthy male and female non-resistance trained participants ingested a commercially available ED standardized at either 1 or 3 mg·kgBM-1of caffeine or a placebo beverage (containing no caffeine) in a randomized, repeated measures design [Citation65]. Sixty minutes following beverage ingestion, each participant completed 10-to-100% 1RM power-load tests for the bench press and half-squat. Ingestion of the ED with 1 mg·kgBM-1of caffeine was not enough to raise the power output during the power-load tests. However, the ingestion of an ED with 3 mg·kgBM-1of caffeine increased maximal power output by 7% in both the half-squat and bench-press as compared to the ingestion of a placebo [Citation65]. A recent study by Gonzalez and colleagues [Citation174] indicated that an energy matrix consisting of caffeine, taurine and glucoronolactone consumed 10-min prior to a workout resulted in an 11.9% improvement (p < 0.05) in the number of repetitions performed during 4 sets of the squat or bench press exercise using 80% of the subject’s 1-RM. In addition, the average power output for the workout was significantly higher for subjects consuming the energy drink compared to subjects consuming the placebo.
In addition to resistance and high intensity anaerobic exercise, the effects that ED exert on speed/agility performance has also been investigated. Collegiate female soccer players ingested an ED containing 1.3 mg·kgBM-1of caffeine and 1 gram of taurine or a caffeine and taurine-free placebo 60 minutes prior to repeated agility t-tests [Citation175]. No difference in agility t-test performance between the ED and placebo groups was reported. Specifically, the highest difference reported between the two groups was during the third set of eight agility t-tests, and the difference reached only 1.15% between the groups. It is unlikely that the carbohydrate content alone in ED is responsible for improvements in resistance exercise performance. In support of this view, the majority of studies in which supplemental carbohydrate was ingested prior to a resistance-training bout did not report improvements in resistance training performance [Citation176–Citation178].
Conclusion
ED (containing approximately 2 mg·kgBM-1caffeine) consumed 45 to 60 minutes prior to anaerobic/resistance exercise may improve upper- and lower- body total lifting volume, but has no effect on repeated high intensity sprint exercise, or on agility performance.
Ingestion prior to endurance exercise
Several studies have investigated the effects of ED ingestion prior to aerobic exercise [Citation62, Citation170–Citation172, Citation179]. In the earliest of these studies, Alford and colleagues [Citation172] investigated the effects of ingesting a commercial ED on aerobic endurance. In a repeated measures, crossover design, young healthy participants ingested 250 mL of a commercial ED (containing 80 mg of caffeine and 26 grams of carbohydrate), a carbonated water beverage, or no beverage at all 30 minutes prior to performing an endurance exercise bout. Test days for separate treatments were assessed within a week. Aerobic performance was analyzed by the amount of time that exercise could be maintained at 65-75% of maximum heart rate on a cycle ergometer. Significant improvements in aerobic performance were reported for the commercial ED treatment. Aerobic performance was 8% and 14% longer after ingesting the commercial ED as compared to the carbonated water and no beverage treatment, respectively.
In one of only two studies that have investigated the effects of ingesting a sugar/carbohydrate-free ED on performance capacity, Candow and colleagues [Citation170] reported no improvements in high intensity run time-to-exhaustion performed at 80% of VO2max on a treadmill in physically active college-aged participants. The sugar-free ED contained 2 mg·kgBM-1caffeine and was ingested one-hour prior to the exercise bout [Citation170]. In contrast, Walsh and colleagues [Citation179] reported significant improvements in treadmill run time to exhaustion following ingestion of a carbohydrate-free ED. In this randomized cross-over investigation, 15 recreationally active participants ingested an ED 10-minutes prior to engaging in a treadmill run-to exhaustion test at 70% VO2max [Citation179]. The ED utilized in this study did not contain any carbohydrate, and unlike other ED products, contained nearly eight grams of the amino acids L-leucine, L-isoleucine, L-valine, L-arginine and L-glutamine. Unfortunately, the published study did not disclose the precise amount of caffeine contained in the ED, but instead referred to a ~2 g “proprietary blend” of caffeine, taurine, and glucoronolactone. The placebo used as a comparison was sweetened water that was similar in color and volume. It was reported that participants consuming the ED were able to run 12.5% longer than during the placebo treatment [Citation179].
The two most common protocols used to assess aerobic performance are time to exhaustion at a given exercise intensity (e.g., exercise at 70% of maximum oxygen uptake until exhaustion) and time trial performance for a set distance (e.g., 40 km time trial). Time trials have greater validity than time to exhaustion because they provide a good physiological simulation of actual performance and correlate with actual performance [Citation180, Citation181]. Ivy and colleagues [Citation62] were the first research group to utilize a time trial component in conjunction with ED consumption. In this investigation, trained male and female cyclists completed two trials in a repeated measures crossover design separated by one week. After a 12 hour fast, the cyclists ingested a commercially available ED providing approximately 2.3 mg·kgBM-1caffeine or an artificially colored, flavored, and sweetened-water placebo 40-minute prior to the exercise bout. Performance during the exercise bout was measured as the time to complete a standardized amount of work equal to 1 hr of cycling at 70% of maximal power output. Results revealed a significant difference between the treatments in relation to performance with the ED treatment completing the time trial ~4.7% faster than the placebo treatment [Citation62].
Conclusion
ED containing approximately 2 mg·kgBM-1caffeine consumed 10 to 40 minutes prior to aerobic exercise improve cycling and running performance in both trained cyclists and recreationally active participants. In the one investigation in which no aerobic performance improvement was reported, the ED (containing 2 mg·kgBM-1caffeine) was ingested 60-minutes prior to the performance assessment. In light of the other findings, ingestion of the caffeine-containing ED 60-minutes prior to the exercise bout may be too long of a period to realize improvements in aerobic exercise performance.
Mood/reaction time/alertness
Reaction time, concentration, alertness, and subjective feelings of energy/vitality are important in many competitive activities such as hitting a baseball, returning a serve in tennis, and dodging strikes and kicks in a mixed martial arts competition. Strategies to improve these attributes are often sought after by individuals competing in certain athletic endeavors. Over the past several years, research has investigated the effects that ED ingestion has on these (and other) variables.
Seidl and coworkers [Citation31] conducted a study utilizing three common ingredients (i.e., caffeine, taurine, glucuronolactone) typically found in ED and compared it to a placebo group. Participants were evaluated at night to see if ingestion of these nutrients affected mood and motor function in fatigued participants. Interestingly, the investigators found that at the end of the experiment, reaction time was significantly longer in the placebo group, but remained unchanged in the group that consumed the ED ingredients. Similarly, vitality scores, feelings of well-being, and social extrovertedness were all significantly decreased in the placebo group, but did not change in the ED group [Citation31].
Scholey and colleagues [Citation182] investigated the effects of an ED (containing primarily caffeine, glucose, ginseng and ginkgo biloba drink) or a placebo beverage on five aspects of cognitive performance and mood. Thirty minutes after consuming ED, two of the five variables (i.e., “secondary memory” and “speed of attention”) were significantly improved as compared to the placebo beverage [Citation182]. Other investigators also reported that when caffeine was combined with carbohydrates in a carbonated beverage, performance and mood were improved and/or maintained during fatiguing and cognitively demanding tasks relative to placebo [Citation183]. Similarly, ED containing caffeine and glucose have also been shown to enhance event related potentials (i.e., a measure of brain activity in real time obtained from an electroencephalogram), which may translate to improvements in reaction time [Citation184].
Hoffman and colleagues [Citation169] reported that when male strength/power athletes consumed 120 ml of a commercially available ED or a placebo, reaction time and subjective feelings of energy and focus were significantly improved in those consuming the ED. Furthermore, the investigators also noted a statistical trend (p=0.06) towards an increase in alertness. In a similar study, Walsh and colleagues [Citation179] examined the effects of ingesting an “energy matrix” (2.05 g of caffeine, taurine, glucuronolactone), amino acids (7.9 g of L-leucine, L-isoleucine, L-valine, L-arginine and L-glutamine), di-creatine citrate (5 g), and β-alanine (2.5 g) mixed with 500 ml of water or a placebo) 10-minutes prior to exercise on aerobic performance and subjective measures of focus, energy, and fatigue in recreationally active male and females. Results revealed that participants ingesting the ED increased time to exhaustion while running at 70% of VO2max by 12.5% (p = 0.012), they reported greater focus (p = 0.031), energy (p = 0.016), and less fatigue (p = 0.005) prior to exercise; and, that their ratings of focus (p = 0.026) and energy (p = 0.004) were greater 10 minutes into exercise [Citation179]. However, no significant differences in energy, fatigue, and focus were observed between groups immediately post-exercise [Citation179].
Howard and coworkers [Citation185] evaluated the effects of acute ingestion of a glucose containing ED on behavioral control. In this study, 80 participants were randomly assigned to consume 1.8, 3.6, or 5.4 ml/kg of an ED, a placebo, or no drink in a counterbalanced manner. Participants completed a behavioral control task and subjective measures of stimulation, sedation, and mental fatigue before and 30-minutes after ingestion of the assigned drinks. Results revealed that those consuming the ED decreased reaction times on the behavioral control task, increased subjective ratings of stimulation and decreased ratings of mental fatigue. The greatest improvements in reaction times and subjective measures were observed with the lower dose and improvements diminished as the dose increased. Earlier research conducted by Alford and associates [Citation172] supported these findings by demonstrating that individuals ingesting 250 ml of this same ED had significantly better reaction time, concentration, memory, and subjective alertness compared to a placebo. Smit and coworkers [Citation183] suggested that caffeine is most likely the primary ingredient that improves mood and performance during fatiguing and cognitively demanding tasks, with carbohydrates playing a minor role. However, caffeine and carbohydrate may act in a synergistic manner [Citation182]. To support this view, a recent paper by Pettitt et al [Citation186] reported that while ingestion of an ED prior to exercise affected aerobic metabolism during and following cycling exercise, the secondary ingredients found in the ED had no additive effects.
Conclusion
To date, most studies on ED have reported improvements in mood, reaction time, and/or markers of alertness, even though the relative importance of the various ingredients is not fully understood. The primary ergogenic value appears to be due to the caffeine and/or carbohydrate contained in these drinks. Individuals looking to enhance reaction time, mental alertness, and/or focus may benefit from consuming an ED prior to exercise.
Energy drinks and their role in energy expenditure and weight loss
As shown in Table , ED and some commercial beverages designed to increase metabolism typically contain a number of stimulants (e.g., caffeine, Guarana, Green Tea, synephrine, Yerba mate, Yohimbine, Tyramine, Vinocetine, etc.). Several low-calorie ED and beverages have been marketed as “thermogenic blends” with a focus on increasing metabolism. Theoretically, ingestion of ED prior to exercise may increase energy expenditure which over time could help manage and/or promote weight loss. In support of this theory, studies have shown that ingestion of caffeine (e.g., 200-500 mg) can increase acute (1-24 hours) energy expenditure [Citation187–Citation193], chronic (28 days) energy expenditure [Citation194], and elevate plasma free-fatty acid and glycerol levels [Citation187, Citation194, Citation195]. Collectively, these findings suggest that the stimulant properties of caffeine contained in ED can elevate an individual’s metabolic rate as well as elevate the rate of lipolysis in the body. However, these studies used various types of caffeine/stimulant/vitamin-enriched coffee [Citation189–Citation193], a caffeine/stimulant blend supplement [Citation187, Citation189, Citation193], and various calorie-free thermogenic ED [Citation190, Citation194–Citation197]. Additionally, the dosage of caffeine used in some of these beverages that are marketed as a thermogenic supplements is typically higher (e.g., 200-500 mg) than the concentrations found in ED and ES marketed for increasing athletic performance or alertness (i.e., about 80 – 200 mg). With this said, there is some data that indicates that acute ingestion of ED has been shown to enhance energy expenditure, metabolic rate, catecholamine secretion, and/or lipolysis [Citation187, Citation198]
In terms of weight loss, Roberts and colleagues [Citation194] reported that 28 days of consumption of a calorie free ED (336 ml/day) promoted small (i.e., 18.9 ± 1.5 to 18.3 ± 1.5 kg) but statistically significant (p<0.05) reductions in fat mass compared to controls (i.e., 18.1 ± 1.3 to 18.4 3± 1.2 kg). Similarly, Stout and associates [Citation199] evaluated the effects of consuming an ED or placebo 15-minutes prior to exercise training and ad-libitum on non-training days for 10-weeks on changes in body composition and fitness. Results revealed that those consuming the ED experienced greater changes in fat mass (-6.6% vs. -0.35%, p<0.05), peak aerobic capacity (+13.8% vs. 5.4%, p<0.01), and treadmill time to exhaustion (+19.7% vs. 14.0%, p<0.01). These findings suggest that consumption of ED during training and/or weight loss may provide some additive ergogenic benefits. However, it should be noted that recent review on ED by Higgins and associates [Citation200] found that many of the commonly used additional ingredients (e.g., Ma Huang, willow bark, synephrine, calcium, cayenne/black pepper extracts) that are contained in the “thermogenic blends” of several of these products are not contained in some of the most commonly used ED. It is also important to note that daily consumption of high calorie ED could promote weight gain. Consequently, additional research is necessary to determine whether ingesting low-calorie ED or ES may affect training adaptations and/or weight loss.
Conclusion
Consumption of low calorie ED and thermogenic beverages have been reported to increase resting energy expenditure and fat metabolism on an acute basis. Preliminary studies suggest that ingesting some types of ED and thermogenic beverages prior to exercise during training could promote positive adaptations in body composition. However, more research is needed to determine whether daily use of ED would affect long-term energy balance and body composition.
Safety considerations
ED have had a negative connotation in the media and more recently medical community, mostly related to potential concerns about excessive caffeine intake [Citation201, Citation202] and/or potential deleterious effects of mixing ED with alcohol [Citation203]. While safety concerns and use of alcohol go beyond the scope of this paper, the reader is referred to a recent viewpoint published in the Journal of the American Medical Association related to safety concerns of mixing ED with alcohol [Citation203]. In terms of use of ED in the traditional sense, most concerns have been based on case studies or adverse event reports that have serve only to document a potential association, but does not establish causality. In reality, there are currently only a few studies (acute or long term) that have investigated the side effects of ED [Citation204–Citation209]. There appear to be two primary active nutrients in most ED and ES (i.e., carbohydrate and caffeine) that may possess safety concerns in some populations. Many ED contain 25 – 50 g of simple sugars, therefore, ingestion of ED prior to exercise are likely to rapidly increase insulin in order to maintain normal blood glucose levels. For this reason, diabetics and pre-diabetics should avoid high glycemic load ED or consider consuming low carbohydrate versions of ED [Citation201, Citation202].
Very often, ED also contain various stimulants with the most common being caffeine. Some concern has been raised about excessive caffeine intake that could be obtained from consuming too many ED and/or from a lack of knowledge that that some ingredients contained in ED may contain caffeine [Citation201, Citation202]. Currently in the United States, the FDA has regulated the limit of caffeine in soft drinks to 0.02 percent (10mg/oz.) of the product, but this is not currently enforced for ED or ES. As of December 2012, the US-FDA along with the US Congress has begun to study products marketed as ED or ES, however no formal new guidelines have been published. The Nutrition Facts Panel on food labels are not required to always list caffeine since it is not a nutrient. However, if caffeine is added to a food, it must then be listed [Citation210]; therefore many individuals may consume more caffeine than they realize [Citation201, Citation202]. In Canada, caffeine levels are limited to 180 mg per drink [Citation211]. The caffeine content of common ED and ES has been reported to range from about 100 to 286 mg [Citation202]. As a comparison, the average cup of coffee or contains between 40 and 150 mg caffeine, while a 20 oz. cup of Starbucks regular drip coffee has been found to contain as much as 480 mg of caffeine [Citation212].
The potential side effects of caffeine include: insomnia, nervousness, restlessness, gastric irritation, nausea, vomiting, tachycardia, tremors, and anxiety; which have been reported at doses as low as 250 to 300 mg [Citation5, Citation201–Citation204, Citation209]. Caffeine availability is ubiquitous and it is one of the most extensively studied substances in the food supply with a long history as generally regarded as safe when consumed in moderation [Citation61]. However, all substances may be toxic under the right conditions, with toxicity being a function of the interaction of many physiologic variables that include the following: acute and chronic dosing, route of administration, genetics, age, sex, environment, and intrinsic health of the individual being exposed. Young adults have been found to have subclinical coronary atherosclerosis [Citation213]. In addition, post-mortem assessment of sudden cardiac death in young persons (<35 years) reveals a variety of anatomic abnormalities of the coronary arteries, myocardium, valves and the conduction system [Citation214]. Such unknown pre-existing risk factors may increase the risk of adverse events, particularly cardiovascular ones, in individuals consuming EDs, due to underlying disease. In fact, even water can be toxic given certain conditions with an LD50 (lethal acute dose for 50 percent in test species) of greater than 90 mL/kg in rats [Citation215]. It is possible to overdose on caffeine and there are a handful of case reports in the literature [Citation5, Citation209, Citation216–Citation218]. A lethal dose of caffeine has been typically in excess of 5 g [Citation217], which equates to about 42 cups of coffee at 120 mg of caffeine per cup. Sepkowitz [Citation201] recently suggested that an intake of 3 grams of caffeine (equivalent to ingesting 12 or so highly caffeinated ED within a few hours) could elicit significant adverse effects. The average caffeine per serving in most ED and ES range between 75 and 200 mg, an amount similar to the caffeine found in a premium cup of coffee [Citation202].
Nawrot and colleagues [Citation219] stated that in a healthy adult population, up to 400 mg of caffeine daily was not associated with any adverse effects. In another review, Higdon et al. [Citation220] presented data in children stating no adverse effects were seen with doses under 3 mg·kgBM-1·day-1. As with most drugs, the exact amount of caffeine where side effects will occur varies from person to person based on genetics, age, liver cytochrome P450-CYP1A2 isozyme function, concurrent medications or substances that may affect hepatic metabolism, body mass, and sensitivity. Additionally, it is unknown whether inclusion of other stimulants in ED and/or ES may increase or decrease the threshold for experiencing side effects. For this reason, some groups do not recommend ED or ES for athletes participating in exercise lasting less than 1 hour [Citation200], despite the admission of inadequate long-term data. The longest duration studies on ED or ES we were able to find was 10 weeks and these studies did not report any change in clinical safety markers [Citation199, Citation206]. Nevertheless, since ED and ES often contain other stimulants that can have a synergistic effect with caffeine, more research is needed to determine the long-term effects of habitual intake of ED and ES before definitive conclusions can be drawn.
Several reports have expressed concern about the safety of ED [Citation5, Citation200, Citation205, Citation221]. For example, Worthley and associates [Citation222] tested 50 young male and female adults one hour before and one hour after consuming 250 ml of a sugar-free ED containing approximately 80 mg of caffeine. The investigators found that mean arterial pressure increased by approximately 3.8 mmHg while resting heart rate was not affected. Additionally, platelet aggregation increased by 13.7% compared to only a 0.3% change in the control group while endothelial function decreased. The researchers noted that the component of the ED that was associated with these results was not clear. However, they suggested that since endothelial dysfunction and impaired platelet function are associated with elevated glucose levels, it is possible that glucuronolactone contained in the ED might have contributed to the observed detrimental effects of energy drinks [Citation222]. More research is needed to corroborate these findings as well as to determine whether these acute changes would pose any long-term health risk.
Bichler and cohorts [Citation26] investigated a combination of caffeine and taurine (two common ingredients in ED) in a double-blind study of college students. Subjects consumed either caffeine and taurine pills or a placebo and then completed a memory assessment while heart rate and blood pressure were monitored. The combination caused a significant decline in heart rate and an increase in mean arterial blood pressure. Steinke et al. [Citation223] studied 15 healthy adults who abstained from caffeine for 48 hours prior to and during the study in addition to being fasted overnight. Baseline measurements of blood pressure and heart rate were measured. On day one of the study, each participant consumed 500 mL (2 cans) of an ED and measurements were repeated 30 minutes, 1 hour, 2 hours, 3 hours, and 4 hours later. Participants also drank 500 mL of the ED drink daily for the next 5 days. The experiment was then repeated after 7-days. The investigators found that maximum mean heart rate occurred at 4 hours with significant increases of 7.8% and 11.0% on days 1 and 7, respectively. Blood pressures were increased approximately 7% after acute ingestion of the ED on day 1 (significant increase) but no differences were seen on day 7. Finally, in a case report, Usman and coworkers [Citation221] reported that a young boy presented with palpitations and high blood pressure after consumption of an ED containing carbohydrate (40 g), sodium citrate, taurine (124 mg), caffeine, inositol (17 mg), Panax ginseng (6.98 mg), and other nutrients. The tachycardia and hypertension returned to normal after discontinuation of ED consumption.
Conclusion
Individuals with certain medical conditions (e.g., metabolic syndrome or diabetes mellitus) should avoid consumption of high glycemic drinks and/or foods and therefore should not consume the high calorie versions of ED. It would be prudent for individuals with known cardiovascular disease to avoid altogether their use of ED and/or ES, or other products with known cardio-stimulant effects. While ED containing caffeine and other stimulants may have negative effects upon health and cardiac parameters in individuals with such pre-existing health conditions, the current evidence (although small) suggests that consumption of ED and ES are safe in healthy populations and similar to ingesting other foods and beverages containing caffeine. Finally, although it is estimated that only 1% of all dietary supplement adverse events are reported to FDA [Citation224], given the number of servings of these products that are consumed daily, the rate of adverse events appears low in the population of consumers. Nevertheless, it is acknowledged that additional short- and long-term studies are needed to better determine any factors that increase the risk for adverse events. Additionally, since ED often contain several nutrients that contain caffeine and/or other stimulants, care should be taken to make sure that an excessive number of ED are not consumed within a short period of time.
Conclusions and recommendations
Based on a review of the available scientific and medical literature related to the safety and efficacy of the use of ED or ES, the Research Committee of the Society makes the following conclusions and recommendations.
Although ED and ES contain a number of nutrients that are purported to affect mental and/or physical performance, the primary ergogenic nutrients in most ED and ES appear to be carbohydrate and/or caffeine.
The ergogenic value of caffeine on mental and physical performance has been well-established but the potential additive benefits of other nutrients contained in ED and ES remains to be determined.
Consuming ED 10-60 minutes before exercise can improve mental focus, alertness, anaerobic performance, and/or endurance performance.
Many ED and ES contain numerous ingredients; these products in particular merit further study to demonstrate their safety and potential effects on physical and mental performance.
There is some limited evidence that consumption of low-calorie ED during training and/or weight loss trials may provide ergogenic benefit and/or promote a small amount of additional fat loss. However, ingestion of higher calorie ED may promote weight gain if the energy intake from consumption of ED is not carefully considered as part of the total daily energy intake.
Athletes should consider the impact of ingesting high glycemic load carbohydrates on metabolic health, blood glucose and insulin levels, as well as the effects of caffeine and other stimulants on motor skill performance.
Children and adolescents should only consider use of ED or ES with parental approval after consideration of the amount of carbohydrate, caffeine, and other nutrients contained in the ED or ES and a thorough understanding of the potential side effects.
Indiscriminant use of ED or ES, especially if more than one serving per day is consumed, may lead to adverse events and harmful side effects.
Diabetics and individuals with pre-existing cardiovascular, metabolic, hepatorenal, and neurologic disease who are taking medications that may be affected by high glycemic load foods, caffeine, and/or other stimulants should avoid use of ED and/or ES unless approved by their physician.
Competing interests
BC has received university and private sector funded grants to conduct research on several dietary supplements and has received compensation for speaking at conferences and writing lay articles/books about dietary supplements. PLB has received compensation for contributing to edited books in relation to sports nutrition. CW has received academic and industry funding related to dietary supplements and honoraria from speaking engagements on the topic. LT has received academic and industry funding related to dietary supplements and honoraria for speaking at conferences. MTN declares no competing interests. MG has received academic and industry funding related to dietary supplementation but declares no competing interests regarding the contents of this manuscript. TNZ has received funding from the dietary supplement industry to conduct clinical research through The Center for Applied Health Sciences, has consulted for several dietary supplement companies, and currently serves as a scientific advisor to Biotest Laboratories. HLL has received funding from industry to conduct clinical research through The Center for Applied Health Sciences, has consulted for multiple dietary supplement and medical food companies, and currently serves as scientific and medical advisor to Nordic Naturals, Inc. JRS serves as a science advisor for Abbott Nutrition. SS has not competing interest to declare. RC has no competing interests to declare. DSK works for a Contract Research Organization that receives funding for clinical trials from the pharmaceutical and nutritional industries, serves as a Nutrition Consultant currently to the United States Tennis Association (USTA), Boca Raton, Florida, and serves as the also as the Florida International University, Department of Athletics, Sports Nutritionist. JA is a Sports Science Advisor to VPX/Redline in Weston FL. RBK has received external funding from industry through the institutions he has been affiliated with to conduct exercise and nutrition research, has served as a legal expert on exercise and nutrition related cases, and currently serves as a scientific advisor for Woodbolt International.
Authors’ contributions
RBK prepared and delivered the presentation on energy drinks at the 2011 International Society of Sports Nutrition (ISSN) National meeting. BC, CW, LT, MTN, and MG developed the presentation into a draft of a position stand for review and editing by RBK. The final draft was then reviewed and edited by TZ, HL, JRH, JRS, SS, RC, DSK and JA. RBK incorporated recommendations into a final draft which was then reviewed, approved, and adopted as the official position of the ISSN by the Research Committee. All authors read and approved the final manuscript.
References
- FroilandK KoszewskiW HingstJ KopeckyL Nutritional supplement use among college athletes and their sources of information Int J Sport Nutr Exerc Metab 2004 14 104 120 15129934
- Hoffman Caffeine and Energy Drinks Strength Cond J 2010 32 15 20 https://doi.org/10.1519/SSC.0b013e3181bdafa0
- HoffmanJR FaigenbaumAD RatamessNA RossR KangJ TenenbaumG Nutritional supplementation and anabolic steroid use in adolescents Med Sci Sports Exerc 2008 40 15 24 1:CAS:528:DC%2BD1cXktVyhsg%3D%3D 18091024 https://doi.org/10.1249/mss.0b013e31815a5181
- PetrocziA NaughtonDP PearceG BaileyR BloodworthA McNameeM Nutritional supplement use by elite young UK athletes: fallacies of advice regarding efficacy J Int Soc Sports Nutr 2008 5 22 2654424 19077317 https://doi.org/10.1186/1550-2783-5-22
- WolkBJ GanetskyM BabuKM Toxicity of energy drinks Curr Opin Pediatr 2012 24 243 251 1:CAS:528:DC%2BC38XntVygsb4%3D 22426157 https://doi.org/10.1097/MOP.0b013e3283506827
- KerksickC HarveyT StoutJ CampbellB WilbornC KreiderR KalmanD ZiegenfussT LopezH LandisJ et al International Society of Sports Nutrition position stand: nutrient timing J Int Soc Sports Nutr 2008 5 17 2575187 18834505 https://doi.org/10.1186/1550-2783-5-17 1:CAS:528:DC%2BC3cXksVKitL0%3D
- GoldsteinER ZiegenfussT KalmanD KreiderR CampbellB WilbornC TaylorL WilloughbyD StoutJ GravesBS et al International society of sports nutrition position stand: caffeine and performance J Int Soc Sports Nutr 2010 7 5 2824625 20205813 https://doi.org/10.1186/1550-2783-7-5 1:CAS:528:DC%2BC3cXksFensb8%3D
- BonatiM LatiniR GallettiF YoungJF TognoniG GarattiniS Caffeine disposition after oral doses Clin Pharmacol Ther 1982 32 98 106 1:CAS:528:DyaL38XkvVCktr4%3D 7083737 https://doi.org/10.1038/clpt.1982.132
- GrahamTE HibbertE SathasivamP Metabolic and exercise endurance effects of coffee and caffeine ingestion J Appl Physiol 1998 85 883 889 1:CAS:528:DyaK1cXmtVKgtb8%3D 9729561
- McLellanTM BellDG The impact of prior coffee consumption on the subsequent ergogenic effect of anhydrous caffeine Int J Sport Nutr Exerc Metab 2004 14 698 708 15657474
- KovacsEM StegenJ BrounsF Effect of caffeinated drinks on substrate metabolism, caffeine excretion, and performance J Appl Physiol 1998 85 709 715 1:CAS:528:DyaK1cXlsFGnsLo%3D 9688750
- OkaH SuzukiS SuzukiH OdaT Increased urinary excretion of L-xylulose in patients with liver cirrhosis Clin Chim Acta 1976 67 131 136 1:CAS:528:DyaE28Xhtlektbc%3D 1248150 https://doi.org/10.1016/0009-8981(76)90251-5
- JeukendrupA BrounsF WagenmakersAJ SarisWH Carbohydrate-electrolyte feedings improve 1 h time trial cycling performance Int J Sports Med 1997 18 125 129 1:STN:280:DyaK2s3js1eqsg%3D%3D 9081269 https://doi.org/10.1055/s-2007-972607
- JeukendrupAE Carbohydrate intake during exercise and performance Nutrition 2004 20 669 677 1:CAS:528:DC%2BD2cXltVGitbs%3D 15212750 https://doi.org/10.1016/j.nut.2004.04.017
- CoyleEF CogganAR HemmertMK IvyJL Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate J Appl Physiol 1986 61 165 172 1:CAS:528:DyaL28XkvFGhsb4%3D 3525502
- JeukendrupAE JentjensR Oxidation of carbohydrate feedings during prolonged exercise: current thoughts, guidelines and directions for future research Sports Med 2000 29 407 424 1:STN:280:DC%2BD3cvpvVamug%3D%3D 10870867 https://doi.org/10.2165/00007256-200029060-00004
- KreiderRB WilbornCD TaylorL CampbellB AlmadaAL CollinsR CookeM EarnestCP GreenwoodM KalmanDS et al ISSN exercise & sport nutrition review: research & recommendations J Int Soc Sports Nutr 2010 7 7 2853497 20181066 https://doi.org/10.1186/1550-2783-7-7 1:CAS:528:DC%2BC3cXksFentr4%3D
- RodriguezNR Di MarcoNM LangleyS American College of Sports Medicine position stand. Nutrition and athletic performance Med Sci Sports Exerc 2009 41 709 731 19225360 https://doi.org/10.1249/MSS.0b013e31890eb86 1:CAS:528:DC%2BD1MXitFSqs7w%3D
- MurrayR BartoliW StofanJ HornM EddyD A comparison of the gastric emptying characteristics of selected sports drinks Int J Sport Nutr 1999 9 263 274 1:STN:280:DyaK1Mvgs1Gjug%3D%3D 10477362
- MaughanRJ LeiperJB Limitations to fluid replacement during exercise Can J Appl Physiol 1999 24 173 187 1:STN:280:DyaK1M3hsVGgtw%3D%3D 10198143 https://doi.org/10.1139/h99-015
- FranconiF LoizzoA GhirlandaG SeghieriG Taurine supplementation and diabetes mellitus Curr Opin Clin Nutr Metab Care 2006 9 32 36 1:CAS:528:DC%2BD28XhsVaqtr0%3D 16444816 https://doi.org/10.1097/01.mco.0000196141.65362.46
- DawsonRJr BiasettiM MessinaS DominyJ The cytoprotective role of taurine in exercise-induced muscle injury Amino Acids 2002 22 309 324 1:CAS:528:DC%2BD38XmvFCqt74%3D 12107759 https://doi.org/10.1007/s007260200017
- ZhangM IzumiI KagamimoriS SokejimaS YamagamiT LiuZ QiB Role of taurine supplementation to prevent exercise-induced oxidative stress in healthy young men Amino Acids 2004 26 203 207 1:CAS:528:DC%2BD2cXkvVygsrs%3D 15042451 https://doi.org/10.1007/s00726-003-0002-3
- ObrosovaIG StevensMJ Effect of dietary taurine supplementation on GSH and NAD(P)-redox status, lipid peroxidation, and energy metabolism in diabetic precataractous lens Invest Ophthalmol Vis Sci 1999 40 680 688 1:STN:280:DyaK1M7msFaqtg%3D%3D 10067971
- BakkerAJ BergHM Effect of taurine on sarcoplasmic reticulum function and force in skinned fast-twitch skeletal muscle fibres of the rat J Physiol 2002 538 185 194 2290020 1:CAS:528:DC%2BD38XislGmsbc%3D 11773327 https://doi.org/10.1113/jphysiol.2001.012872
- BichlerA SwensonA HarrisMA A combination of caffeine and taurine has no effect on short term memory but induces changes in heart rate and mean arterial blood pressure Amino Acids 2006 31 471 476 1:CAS:528:DC%2BD28Xht1GmsrzE 16699827 https://doi.org/10.1007/s00726-005-0302-x
- GallowaySD TalanianJL ShovellerAK HeigenhauserGJ SprietLL Seven days of oral taurine supplementation does not increase muscle taurine content or alter substrate metabolism during prolonged exercise in humans J Appl Physiol 2008 105 643 651 1:CAS:528:DC%2BD1cXhtVKnsrfI 18583380 https://doi.org/10.1152/japplphysiol.90525.2008
- MatsuzakiY MiyazakiT MiyakawaS BouscarelB IkegamiT TanakaN Decreased taurine concentration in skeletal muscles after exercise for various durations Med Sci Sports Exerc 2002 34 793 797 1:CAS:528:DC%2BD38Xkt1aktLo%3D 11984297 https://doi.org/10.1097/00005768-200205000-00011
- RutherfordJA SprietLL StellingwerffT The effect of acute taurine ingestion on endurance performance and metabolism in well-trained cyclists Int J Sport Nutr Exerc Metab 2010 20 322 329 1:CAS:528:DC%2BC3cXhsFyhurrO 20739720
- WardRJ FrancauxM CuisinierC SturboisX De WitteP Changes in plasma taurine levels after different endurance events Amino Acids 1999 16 71 77 1:CAS:528:DyaK1MXjslagsLg%3D 10078335 https://doi.org/10.1007/BF01318886
- SeidlR PeyrlA NichamR HauserE A taurine and caffeine-containing drink stimulates cognitive performance and well-being Amino Acids 2000 19 635 642 1:CAS:528:DC%2BD3MXotFWjsw%3D%3D 11140366 https://doi.org/10.1007/s007260070013
- GoodmanCA HorvathD StathisC MoriT CroftK MurphyRM HayesA Taurine supplementation increases skeletal muscle force production and protects muscle function during and after high-frequency in vitro stimulation J Appl Physiol 2009 107 144 154 2711783 1:CAS:528:DC%2BD1MXovFKqtLk%3D 19423840 https://doi.org/10.1152/japplphysiol.00040.2009
- WangFR DongXF TongJM ZhangXM ZhangQ WuYY Effects of dietary taurine supplementation on growth performance and immune status in growing Japanese quail (Coturnix coturnix japonica) Poult Sci 2009 88 1394 1398 1:CAS:528:DC%2BD1MXpt1OmtLY%3D 19531709 https://doi.org/10.3382/ps.2009-00022
- PiernoS De LucaA CamerinoC HuxtableRJ CamerinoDC Chronic administration of taurine to aged rats improves the electrical and contractile properties of skeletal muscle fibers J Pharmacol Exp Ther 1998 286 1183 1190 1:CAS:528:DyaK1cXmt1Gru7g%3D 9732377
- WarburtonDM BerselliniE SweeneyE An evaluation of a caffeinated taurine drink on mood, memory and information processing in healthy volunteers without caffeine abstinence Psychopharmacology (Berl) 2001 158 322 328 1:CAS:528:DC%2BD3MXpt1Cls7s%3D https://doi.org/10.1007/s002130100884
- JormAF RodgersB ChristensenH Use of medications to enhance memory in a large community sample of 60-64 year olds Int Psychogeriatr 2004 16 209 217 15318765 https://doi.org/10.1017/S1041610204000298
- ElsabaghS HartleyDE FileSE Limited cognitive benefits in Stage +2 postmenopausal women after 6 weeks of treatment with Ginkgo biloba J Psychopharmacol 2005 19 173 181 1:CAS:528:DC%2BD2MXhtVSlt7bK 15728439 https://doi.org/10.1177/0269881105049038
- WalesiukA TrofimiukE BraszkoJJ Gingko biloba extract diminishes stress-induced memory deficits in rats Pharmacol Rep 2005 57 176 187 15886416
- StollS ScheuerK PohlO MullerWE Ginkgo biloba extract (EGb 761) independently improves changes in passive avoidance learning and brain membrane fluidity in the aging mouse Pharmacopsychiatry 1996 29 144 149 1:STN:280:DyaK2s%2FhtFOhsw%3D%3D 8858713 https://doi.org/10.1055/s-2007-979561
- GrevetEH TietzmannMR ShansisFM HastenpfluglC SantanaLC ForsterL KapczinskilF IzquierdoI Behavioural effects of acute phenylalanine and tyrosine depletion in healthy male volunteers J Psychopharmacol 2002 16 51 55 1:CAS:528:DC%2BD38Xjt1yms7c%3D 11949772 https://doi.org/10.1177/026988110201600103
- MahoneyCR CastellaniJ KramerFM YoungA LiebermanHR Tyrosine supplementation mitigates working memory decrements during cold exposure Physiol Behav 2007 92 575 582 1:CAS:528:DC%2BD2sXht1GlsbbK 17585971 https://doi.org/10.1016/j.physbeh.2007.05.003
- ChinevereTD SawyerRD CreerAR ConleeRK ParcellAC Effects of L-tyrosine and carbohydrate ingestion on endurance exercise performance J Appl Physiol 2002 93 1590 1597 1:CAS:528:DC%2BD38Xosl2lsro%3D 12381742 https://doi.org/10.1152/japplphysiol.00625.2001
- DeijenJB WientjesCJ VullinghsHF CloinPA LangefeldJJ Tyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training course Brain Res Bull 1999 48 203 209 1:CAS:528:DyaK1MXivVGrurY%3D 10230711 https://doi.org/10.1016/S0361-9230(98)00163-4
- SalterCA Dietary tyrosine as an aid to stress resistance among troops Mil Med 1989 154 144 146 1:STN:280:DyaL1M3hvFKlug%3D%3D 2496341
- SmithML HanleyWB ClarkeJT KlimP SchoonheytW AustinV LehotayDC Randomised controlled trial of tyrosine supplementation on neuropsychological performance in phenylketonuria Arch Dis Child 1998 78 116 121 1717450 1:STN:280:DyaK1c3ktVeitg%3D%3D 9579151 https://doi.org/10.1136/adc.78.2.116
- MagillRA WatersWF BrayGA VolaufovaJ SmithSR LiebermanHR McNevinN RyanDH Effects of tyrosine, phentermine, caffeine D-amphetamine, and placebo on cognitive and motor performance deficits during sleep deprivation Nutr Neurosci 2003 6 237 246 1:CAS:528:DC%2BD3sXltlWnurs%3D 12887140 https://doi.org/10.1080/1028415031000120552
- WatersWF MagillRA BrayGA VolaufovaJ SmithSR LiebermanHR RoodJ HurryM AndersonT RyanDH A comparison of tyrosine against placebo, phentermine, caffeine, and D-amphetamine during sleep deprivation Nutr Neurosci 2003 6 221 235 1:CAS:528:DC%2BD3sXltlWnuro%3D 12887139 https://doi.org/10.1080/1028415031000120543
- O’BrienC MahoneyC TharionWJ SilsIV CastellaniJW Dietary tyrosine benefits cognitive and psychomotor performance during body cooling Physiol Behav 2007 90 301 307 17078981 https://doi.org/10.1016/j.physbeh.2006.09.027 1:CAS:528:DC%2BD2sXhtlSktLk%3D
- WieselFA EdmanG FlycktL ErikssonA NymanH VenizelosN BjerkenstedtL Kinetics of tyrosine transport and cognitive functioning in schizophrenia Schizophr Res 2005 74 81 89 15694757 https://doi.org/10.1016/j.schres.2004.07.009
- StruderHK HollmannW PlatenP DonikeM GotzmannA WeberK Influence of paroxetine, branched-chain amino acids and tyrosine on neuroendocrine system responses and fatigue in humans Horm Metab Res 1998 30 188 194 1:STN:280:DyaK1c3osFSqsg%3D%3D 9623632 https://doi.org/10.1055/s-2007-978864
- JagerR PurpuraM KingsleyM Phospholipids and sports performance J Int Soc Sports Nutr 2007 4 5 1997116 17908342 https://doi.org/10.1186/1550-2783-4-5
- WarberJP PattonJF TharionWJ ZeiselSH MelloRP KemnitzCP LiebermanHR The effects of choline supplementation on physical performance Int J Sport Nutr Exerc Metab 2000 10 170 181 1:CAS:528:DC%2BD3cXltlOjsbg%3D 10861337
- TurnerEH LoftisJM BlackwellAD Serotonin a la carte: supplementation with the serotonin precursor 5-hydroxytryptophan Pharmacol Ther 2006 109 325 338 1:CAS:528:DC%2BD28Xnslylsg%3D%3D 16023217 https://doi.org/10.1016/j.pharmthera.2005.06.004
- ChaouloffF LaudeD ElghoziJL Physical exercise: evidence for differential consequences of tryptophan on 5-HT synthesis and metabolism in central serotonergic cell bodies and terminals J Neural Transm 1989 78 121 130 1:STN:280:DyaK3c%2FjvFarsA%3D%3D 2478662 https://doi.org/10.1007/BF01252498
- Leu-SemenescuS ArnulfI DecaixC MoussaF ClotF BoniolC TouitouY LevyR VidailhetM RozeE Sleep and rhythm consequences of a genetically induced loss of serotonin Sleep 2010 33 307 314 2831424 20337188
- FreemanMP HelgasonC HillRA Selected integrative medicine treatments for depression: considerations for women J Am Med Womens Assoc 2004 59 216 224 15354376
- LarzelereMM WisemanP Anxiety, depression, and insomnia Prim Care 2002 29 339 360 12391715 https://doi.org/10.1016/S0095-4543(01)00003-3 vii
- ThachilAF MohanR BhugraD The evidence base of complementary and alternative therapies in depression J Affect Disord 2007 97 23 35 1:STN:280:DC%2BD28jkvF2iuw%3D%3D 16926053 https://doi.org/10.1016/j.jad.2006.06.021
- HayashiY Jacob-VadakotS DuganEA McBrideS OlexaR SimanskyK MurrayM ShumskyJS 5-HT precursor loading, but not 5-HT receptor agonists, increases motor function after spinal cord contusion in adult rats Exp Neurol 2010 221 68 78 2812640 1:CAS:528:DC%2BC3cXotFWm 19840787 https://doi.org/10.1016/j.expneurol.2009.10.003
- YamamotoT NewsholmeEA Diminished central fatigue by inhibition of the L-system transporter for the uptake of tryptophan Brain Res Bull 2000 52 35 38 1:CAS:528:DC%2BD3cXisFGqsbY%3D 10779700 https://doi.org/10.1016/S0361-9230(99)00276-2
- HeckmanMA WeilJ Gonzalez de MejiaE Caffeine (1, 3, 7-trimethylxanthine) in foods: a comprehensive review on consumption, functionality, safety, and regulatory matters J Food Sci 2010 75 R77 87 1:CAS:528:DC%2BC3cXkvFOrsrg%3D 20492310 https://doi.org/10.1111/j.1750-3841.2010.01561.x
- IvyJL KammerL DingZ WangB BernardJR LiaoYH HwangJ Improved cycling time-trial performance after ingestion of a caffeine energy drink Int J Sport Nutr Exerc Metab 2009 19 61 78 1:CAS:528:DC%2BD1MXjvVWnsrY%3D 19403954
- GoldsteinE JacobsPL WhitehurstM PenhollowT AntonioJ Caffeine enhances upper body strength in resistance-trained women J Int Soc Sports Nutr 2010 7 18 2876999 20470411 https://doi.org/10.1186/1550-2783-7-18 1:CAS:528:DC%2BC3cXmslajt7w%3D
- Del CosoJ Muñoz-FernándezVE MuñozG Fernández-ElíasVE OrtegaJF HamoutiN BarberoJC Muñoz-GuerraJ Effects of a Caffeine-Containing Energy Drink on Simulated Soccer Performance PLoS One 2012 7 e31380 3279366 1:CAS:528:DC%2BC38XivFaqsbY%3D 22348079 https://doi.org/10.1371/journal.pone.0031380
- Del CosoJ SalineroJJ Gonzalez-MillanC Abian-VicenJ Perez-GonzalezB Dose response effects of a caffeine-containing energy drink on muscle performance: a repeated measures design J Int Soc Sports Nutr 2012 9 21 3461468 1:CAS:528:DC%2BC38XhtFCqsLrP 22569090 https://doi.org/10.1186/1550-2783-9-21
- Berube-ParentS PelletierC DoreJ TremblayA Effects of encapsulated green tea and Guarana extracts containing a mixture of epigallocatechin-3-gallate and caffeine on 24 h energy expenditure and fat oxidation in men Br J Nutr 2005 94 432 436 1:CAS:528:DC%2BD2MXhtFWit7jK 16176615 https://doi.org/10.1079/BJN20051502
- BelzaA ToubroS AstrupA The effect of caffeine, green tea and tyrosine on thermogenesis and energy intake Eur J Clin Nutr 2009 63 57 64 1:CAS:528:DC%2BD1MXjtFOquw%3D%3D 17882140 https://doi.org/10.1038/sj.ejcn.1602901
- EichenbergerP ColombaniPC MettlerS Effects of 3-week consumption of green tea extracts on whole-body metabolism during cycling exercise in endurance-trained men Int J Vitam Nutr Res 2009 79 24 33 1:CAS:528:DC%2BD1MXht12qu7bN 19839000 https://doi.org/10.1024/0300-9831.79.1.24
- VenablesMC HulstonCJ CoxHR JeukendrupAE Green tea extract ingestion, fat oxidation, and glucose tolerance in healthy humans Am J Clin Nutr 2008 87 778 784 1:CAS:528:DC%2BD1cXjsVagur8%3D 18326618
- EichenbergerP MettlerS ArnoldM ColombaniPC No Effects of Three-week Consumption of a Green Tea Extract on Time Trial Performance in Endurance-trained Men Int J Vitam Nutr Res 2010 80 54 64 1:CAS:528:DC%2BC3cXptVeksL4%3D 20533245 https://doi.org/10.1024/0300-9831/a000006
- ChenN BezzinaR HinchE LewandowskiPA Cameron-SmithD MathaiML JoisM SinclairAJ BeggDP WarkJD et al Green tea, black tea, and epigallocatechin modify body composition, improve glucose tolerance, and differentially alter metabolic gene expression in rats fed a high-fat diet Nutr Res 2009 29 784 793 1:CAS:528:DC%2BD1MXhsVKgsr3F 19932867 https://doi.org/10.1016/j.nutres.2009.10.003
- HurselR Westerterp-PlantengaMS Green tea catechin plus caffeine supplementation to a high-protein diet has no additional effect on body weight maintenance after weight loss Am J Clin Nutr 2009 89 822 830 1:CAS:528:DC%2BD1MXjtFGltbo%3D 19176733 https://doi.org/10.3945/ajcn.2008.27043
- AuvichayapatP PrapochanungM TunkamnerdthaiO SripanidkulchaiBO AuvichayapatN ThinkhamropB KunhasuraS WongpratoomS SinawatS HongprapasP Effectiveness of green tea on weight reduction in obese Thais: A randomized, controlled trial Physiol Behav 2008 93 486 491 1:CAS:528:DC%2BD1cXhslGnsbo%3D 18006026 https://doi.org/10.1016/j.physbeh.2007.10.009
- DiepvensK KovacsEM NijsIM VogelsN Westerterp-PlantengaMS Effect of green tea on resting energy expenditure and substrate oxidation during weight loss in overweight females Br J Nutr 2005 94 1026 1034 1:CAS:528:DC%2BD28XpvVCmtA%3D%3D 16351782 https://doi.org/10.1079/BJN20051580
- DiepvensK WesterterpKR Westerterp-PlantengaMS Obesity and thermogenesis related to the consumption of caffeine, ephedrine, capsaicin, and green tea Am J Physiol Regul Integr Comp Physiol 2007 292 R77 85 1:CAS:528:DC%2BD2sXisFGitL4%3D 16840650 https://doi.org/10.1152/ajpregu.00832.2005
- MuraseT HaramizuS ShimotoyodomeA TokimitsuI HaseT Green tea extract improves running endurance in mice by stimulating lipid utilization during exercise Am J Physiol Regul Integr Comp Physiol 2006 290 R1550 1556 1:CAS:528:DC%2BD28XlvVekurc%3D 16410398 https://doi.org/10.1152/ajpregu.00752.2005
- Fugh-BermanA MyersA Citrus aurantium, an ingredient of dietary supplements marketed for weight loss: current status of clinical and basic research Exp Biol Med (Maywood) 2004 229 698 704 1:CAS:528:DC%2BD2cXnsVeitrk%3D
- HallerCA BenowitzNL JacobP Hemodynamic effects of ephedra-free weight-loss supplements in humans Am J Med 2005 118 998 1003 16164886 https://doi.org/10.1016/j.amjmed.2005.02.034
- KimGS ParkHJ WooJH KimMK KohPO MinW KoYG KimCH WonCK ChoJH Citrus aurantium flavonoids inhibit adipogenesis through the Akt signaling pathway in 3T3-L1 cells BMC Complement Altern Med 2012 12 31 3350436 1:CAS:528:DC%2BC38XnvFSmsrc%3D 22471389 https://doi.org/10.1186/1472-6882-12-31
- PeixotoJS ComarJF MoreiraCT SoaresAA de OliveiraAL BrachtA PeraltaRM Effects of Citrus aurantium (bitter orange) fruit extracts and p-synephrine on metabolic fluxes in the rat liver Molecules 2012 17 5854 5869 1:CAS:528:DC%2BC38XnvFGlurs%3D 22592089 https://doi.org/10.3390/molecules17055854
- PreussHG DiFerdinandoD BagchiM BagchiD Citrus aurantium as a thermogenic, weight-reduction replacement for ephedra: an overview J Med 2002 33 247 264 12939122
- StohsSJ PreussHG KeithSC KeithPL MillerH KaatsGR Effects of p-synephrine alone and in combination with selected bioflavonoids on resting metabolism, blood pressure, heart rate and self-reported mood changes Int J Med Sci 2011 8 295 301 3085176 1:CAS:528:DC%2BC3MXmsFGrtbc%3D 21537493 https://doi.org/10.7150/ijms.8.295
- PittlerMH ErnstE Dietary supplements for body-weight reduction: a systematic review Am J Clin Nutr 2004 79 529 536 1:CAS:528:DC%2BD2cXivFyktrc%3D 15051593
- PittlerMH SchmidtK ErnstE Adverse events of herbal food supplements for body weight reduction: systematic review Obes Rev 2005 6 93 111 1:CAS:528:DC%2BD2MXkvFyrsrw%3D 15836459 https://doi.org/10.1111/j.1467-789X.2005.00169.x
- KangYR LeeHY KimJH MoonDI SeoMY ParkSH ChoiKH KimCR KimSH OhJH et al Anti-obesity and anti-diabetic effects of Yerba Mate (Ilex paraguariensis) in C57BL/6J mice fed a high-fat diet Lab Anim Res 2012 28 23 29 3315195 22474471 https://doi.org/10.5625/lar.2012.28.1.23
- RileyAJ Yohimbine in the treatment of erectile disorder Br J Clin Pract 1994 48 133 136 1:STN:280:DyaK2czgsVOmsg%3D%3D 8031688
- GuptaRS SharmaR SharmaA BhatnagerAK DobhalMP JoshiYC SharmaMC Effect of Alstonia scholaris bark extract on testicular function of Wistar rats Asian J Androl 2002 4 175 178 1:STN:280:DC%2BD38ngvFGksQ%3D%3D 12364971
- PorstH The future of erectile dysfunction (ED) Arch Esp Urol 2010 63 740 747 21048284
- KucioC JonderkoK PiskorskaD Does yohimbine act as a slimming drug? Isr J Med Sci 1991 27 550 556 1:STN:280:DyaK38%2FmsVCnsg%3D%3D 1955308
- SaxL Yohimbine does not affect fat distribution in men Int J Obes 1991 15 561 565 1:CAS:528:DyaK38Xls1U%3D 1960007
- deMarcaidaJA SchwidSR WhiteWB BlindauerK FahnS KieburtzK SternM ShoulsonI Effects of tyramine administration in Parkinson’s disease patients treated with selective MAO-B inhibitor rasagiline Mov Disord 2006 21 1716 1721 16856145 https://doi.org/10.1002/mds.21048
- ConlayLA MaherTJ WurtmanRJ Tyrosine’s pressor effect in hypotensive rats is not mediated by tyramine Life Sci 1984 35 1207 1212 1:CAS:528:DyaL2cXlt1ekt74%3D 6472051 https://doi.org/10.1016/0024-3205(84)90192-9
- EdwardsDJ Possible role of octopamine and tyramine in the antihypertensive and antidepressant effects of tyrosine Life Sci 1982 30 1427 1434 1:CAS:528:DyaL38Xhsleqsr4%3D 6177996 https://doi.org/10.1016/0024-3205(82)90556-2
- McDanielMA MaierSF EinsteinGO “Brain-specific” nutrients: a memory cure? Nutrition 2003 19 957 975 1:CAS:528:DC%2BD3sXptVWmu7Y%3D 14624946 https://doi.org/10.1016/S0899-9007(03)00024-8
- PolichJ GloriaR Cognitive effects of a Ginkgo biloba/vinpocetine compound in normal adults: systematic assessment of perception, attention and memory Hum Psychopharmacol 2001 16 409 416 1:CAS:528:DC%2BD3MXms1SrsrY%3D 12404561 https://doi.org/10.1002/hup.308
- BahrkeMS MorganWP StegnerA Is ginseng an ergogenic aid? Int J Sport Nutr Exerc Metab 2009 19 298 322 1:CAS:528:DC%2BD1MXosVaqs7c%3D 19574616
- EngelsHJ FahlmanMM WirthJC Effects of ginseng on secretory IgA, performance, and recovery from interval exercise Med Sci Sports Exerc 2003 35 690 696 12673155 https://doi.org/10.1249/01.MSS.0000058363.23986.D2
- GouletED DionneIJ Assessment of the effects of eleutherococcus senticosus on endurance performance Int J Sport Nutr Exerc Metab 2005 15 75 83 15902991
- HsuCC HoMC LinLC SuB HsuMC American ginseng supplementation attenuates creatine kinase level induced by submaximal exercise in human beings World J Gastroenterol 2005 11 5327 5331 4622803 1:CAS:528:DC%2BD2MXht1elurjP 16149140 https://doi.org/10.3748/wjg.v11.i34.5327
- HwangHJ KwakYS YoonGA KangMH ParkJH LeeBK KimSJ UmSY KimYM Combined effects of swim training and ginseng supplementation on exercise performance time, ROS, lymphocyte proliferation, and DNA damage following exhaustive exercise stress Int J Vitam Nutr Res 2007 77 289 296 1:CAS:528:DC%2BD2sXhsVWitrzI 18271284 https://doi.org/10.1024/0300-9831.77.4.289
- KulaputanaO ThanakomsirichotS AnomasiriW Ginseng supplementation does not change lactate threshold and physical performances in physically active Thai men J Med Assoc Thai 2007 90 1172 1179 17624213
- LiangMT PodolkaTD ChuangWJ Panax notoginseng supplementation enhances physical performance during endurance exercise J Strength Cond Res 2005 19 108 114 15744902 https://doi.org/10.1519/00124278-200502000-00019
- ReayJL ScholeyAB MilneA FenwickJ KennedyDO Panax ginseng has no effect on indices of glucose regulation following acute or chronic ingestion in healthy volunteers Br J Nutr 2009 101 1673 1678 1:CAS:528:DC%2BD1MXotlCntrs%3D 19017419 https://doi.org/10.1017/S0007114508123418
- EngelsHJ KolokouriI CieslakTJ WirthJC Effects of ginseng supplementation on supramaximal exercise performance and short-term recovery J Strength Cond Res 2001 15 290 295 1:STN:280:DC%2BD3MnmsV2mtA%3D%3D 11710653
- EschbachLF WebsterMJ BoydJC McArthurPD EvetovichTK The effect of siberian ginseng (Eleutherococcus senticosus) on substrate utilization and performance Int J Sport Nutr Exerc Metab 2000 10 444 451 1:STN:280:DC%2BD3MzitFSjtw%3D%3D 11099371
- FerrandoA VilaL VocesJA CabralAC AlvarezAI PrietoJG Effects of ginseng extract on various haematological parameters during aerobic exercise in the rat Planta Med 1999 65 288 290 1:CAS:528:DyaK1MXisFSksLs%3D 10232085 https://doi.org/10.1055/s-2006-960783
- FerrandoA VilaL VocesJA CabralAC AlvarezAI PrietoJG Effects of a standardized Panax ginseng extract on the skeletal muscle of the rat: a comparative study in animals at rest and under exercise Planta Med 1999 65 239 244 1:CAS:528:DyaK1MXisFSksrk%3D 10232069 https://doi.org/10.1055/s-1999-14081
- ZiembaAW ChmuraJ Kaciuba-UscilkoH NazarK WisnikP GawronskiW Ginseng treatment improves psychomotor performance at rest and during graded exercise in young athletes Int J Sport Nutr 1999 9 371 377 1:CAS:528:DC%2BD3cXjsFymsg%3D%3D 10660868
- AllenJD McLungJ NelsonAG WelschM Ginseng supplementation does not enhance healthy young adults’ peak aerobic exercise performance J Am Coll Nutr 1998 17 462 466 1:CAS:528:DyaK1cXmslCjtr8%3D 9791844 https://doi.org/10.1080/07315724.1998.10718795
- EngelsHJ WirthJC No ergogenic effects of ginseng (Panax ginseng C.A. Meyer) during graded maximal aerobic exercise J Am Diet Assoc 1997 97 1110 1115 1:STN:280:DyaK2svnslGmtg%3D%3D 9336557 https://doi.org/10.1016/S0002-8223(97)00271-X
- PieralisiG RipariP VecchietL Effects of a standardized ginseng extract combined with dimethylaminoethanol bitartrate, vitamins, minerals, and trace elements on physical performance during exercise Clin Ther 1991 13 373 382 1:STN:280:DyaK38%2FmtlGhug%3D%3D 1954639
- KarlicH LohningerA Supplementation of L-carnitine in athletes: does it make sense? Nutrition 2004 20 709 715 1:CAS:528:DC%2BD2cXltVGiuro%3D 15212755 https://doi.org/10.1016/j.nut.2004.04.003
- PaulyDF PepineCJ D-Ribose as a supplement for cardiac energy metabolism J Cardiovasc Pharmacol Ther 2000 5 249 258 1:CAS:528:DC%2BD3cXotlyrtrs%3D 11150394 https://doi.org/10.1054/JCPT.2000.18011
- KerksickC RasmussenC BowdenR LeutholtzB HarveyT EarnestC GreenwoodM AlmadaA KreiderR Effects of ribose supplementation prior to and during intense exercise on anaerobic capacity and metabolic markers Int J Sport Nutr Exerc Metab 2005 15 653 664 1:CAS:528:DC%2BD28XltVKksw%3D%3D 16521849
- KreiderRB MeltonC GreenwoodM RasmussenC LundbergJ EarnestC AlmadaA Effects of oral D-ribose supplementation on anaerobic capacity and selected metabolic markers in healthy males Int J Sport Nutr Exerc Metab 2003 13 76 86 1:CAS:528:DC%2BD3sXis1Gmsbo%3D 12660407
- BerardiJM ZiegenfussTN Effects of ribose supplementation on repeated sprint performance in men J Strength Cond Res 2003 17 47 52 12580655
- DunneL WorleyS MackninM Ribose versus dextrose supplementation, association with rowing performance: a double-blind study Clin J Sport Med 2006 16 68 71 16377979 https://doi.org/10.1097/01.jsm.0000180022.44889.94
- EijndeBO Van LeemputteM BrounsF Van Der VusseGJ LabarqueV RamaekersM Van SchuylenbergR VerbessemP WijnenH HespelP No effects of oral ribose supplementation on repeated maximal exercise and de novo ATP resynthesis J Appl Physiol 2001 91 2275 2281 1:STN:280:DC%2BD3Mrmtlertw%3D%3D 11641371
- HellstenY SkadhaugeL BangsboJ Effect of ribose supplementation on resynthesis of adenine nucleotides after intense intermittent training in humans Am J Physiol Regul Integr Comp Physiol 2004 286 R182 188 1:CAS:528:DC%2BD2cXot1Sltw%3D%3D 14660478 https://doi.org/10.1152/ajpregu.00286.2003
- HarrisRC SaleC Beta-alanine supplementation in high-intensity exercise Med Sport Sci 2013 59 1 17 https://doi.org/10.1159/000342372
- HoffmanJR EmersonNS StoutJR beta-Alanine supplementation Curr Sports Med Rep 2012 11 189 195 22777329 https://doi.org/10.1249/JSR.0b013e3182604983
- HarrisRC WiseJA PriceKA KimHJ KimCK SaleC Determinants of muscle carnosine content Amino Acids 2012 43 5 12 3374101 1:CAS:528:DC%2BC38XotlOhtrg%3D 22327512 https://doi.org/10.1007/s00726-012-1233-y
- CulbertsonJY KreiderRB GreenwoodM CookeM Effects of beta-alanine on muscle carnosine and exercise performance: a review of the current literature Nutrients 2010 2 75 98 3257613 1:CAS:528:DC%2BC3cXhsV2mtbo%3D 22253993 https://doi.org/10.3390/nu2010075
- HobsonRM SaundersB BallG HarrisRC SaleC Effects of beta-alanine supplementation on exercise performance: a meta-analysis Amino Acids 2012 43 25 37 3374095 1:CAS:528:DC%2BC38XotlOhtrY%3D 22270875 https://doi.org/10.1007/s00726-011-1200-z
- Smith-RyanAE FukudaDH StoutJR KendallKL High-velocity intermittent running: effects of beta-alanine supplementation J Strength Cond Res 2012 26 2798 2805 22797003 https://doi.org/10.1519/JSC.0b013e318267922b
- SaundersB SunderlandC HarrisRC SaleC beta-alanine supplementation improves YoYo intermittent recovery test performance J Int Soc Sports Nutr 2012 9 39 3470991 1:CAS:528:DC%2BC38XhvVSiur%2FF 22928989 https://doi.org/10.1186/1550-2783-9-39
- JagimAR WrightGA BriceAG DobersteinST Effects of beta-alanine supplementation on sprint endurance J Strength Cond Res 2012
- SaleC SaundersB HudsonS WiseJA HarrisRC SunderlandCD Effect of beta-alanine plus sodium bicarbonate on high-intensity cycling capacity Med Sci Sports Exerc 2011 43 1972 1978 1:CAS:528:DC%2BC3MXhtF2jtrzP 21407127
- KernBD RobinsonTL Effects of beta-alanine supplementation on performance and body composition in collegiate wrestlers and football players J Strength Cond Res 2011 25 1804 1815 21659893 https://doi.org/10.1519/JSC.0b013e3181e741cf
- WalterAA SmithAE KendallKL StoutJR CramerJT Six weeks of high-intensity interval training with and without beta-alanine supplementation for improving cardiovascular fitness in women J Strength Cond Res 2010 24 1199 1207 20386120 https://doi.org/10.1519/JSC.0b013e3181d82f8b
- SweeneyKM WrightGA Glenn BriceA DobersteinST The effect of beta-alanine supplementation on power performance during repeated sprint activity J Strength Cond Res 2010 24 79 87 19935102 https://doi.org/10.1519/JSC.0b013e3181c63bd5
- SaleC SaundersB HarrisRC Effect of beta-alanine supplementation on muscle carnosine concentrations and exercise performance Amino Acids 2010 39 321 333 1:CAS:528:DC%2BC3cXotVaisL4%3D 20091069 https://doi.org/10.1007/s00726-009-0443-4
- Van ThienenR Van ProeyenK Vanden EyndeB PuypeJ LefereT HespelP Beta-alanine improves sprint performance in endurance cycling Med Sci Sports Exerc 2009 41 898 903 1:CAS:528:DC%2BD1MXjtlOhtbo%3D 19276843 https://doi.org/10.1249/MSS.0b013e31818db708
- SmithAE MoonJR KendallKL GraefJL LockwoodCM WalterAA BeckTW CramerJT StoutJR The effects of beta-alanine supplementation and high-intensity interval training on neuromuscular fatigue and muscle function Eur J Appl Physiol 2009 105 357 363 1:CAS:528:DC%2BD1MXotVGlsg%3D%3D 18989693 https://doi.org/10.1007/s00421-008-0911-7
- KendrickIP KimHJ HarrisRC KimCK DangVH LamTQ BuiTT WiseJA The effect of 4 weeks beta-alanine supplementation and isokinetic training on carnosine concentrations in type I and II human skeletal muscle fibres Eur J Appl Physiol 2009 106 131 138 1:CAS:528:DC%2BD1MXkvValtLk%3D 19214556 https://doi.org/10.1007/s00421-009-0998-5
- StoutJR GravesBS SmithAE HartmanMJ CramerJT BeckTW HarrisRC The effect of beta-alanine supplementation on neuromuscular fatigue in elderly (55-92 Years): a double-blind randomized study J Int Soc Sports Nutr 2008 5 21 2585553 18992136 https://doi.org/10.1186/1550-2783-5-21 1:CAS:528:DC%2BC3cXksVKitLg%3D
- HoffmanJR RatamessNA FaigenbaumAD RossR KangJ StoutJR WiseJA Short-duration beta-alanine supplementation increases training volume and reduces subjective feelings of fatigue in college football players Nutr Res 2008 28 31 35 1:CAS:528:DC%2BD1cXptlahtg%3D%3D 19083385 https://doi.org/10.1016/j.nutres.2007.11.004
- ZoellerRF StoutJR O’KroyJA TorokDJ MielkeM Effects of 28 days of beta-alanine and creatine monohydrate supplementation on aerobic power, ventilatory and lactate thresholds, and time to exhaustion Amino Acids 2007 33 505 510 1:CAS:528:DC%2BD2sXpvVahu74%3D 16953366 https://doi.org/10.1007/s00726-006-0399-6
- EinatH BelmakerRH The effects of inositol treatment in animal models of psychiatric disorders J Affect Disord 2001 62 113 121 1:CAS:528:DC%2BD3MXlt1ykurk%3D 11172878 https://doi.org/10.1016/S0165-0327(00)00355-4
- SuredaA PonsA Arginine and citrulline supplementation in sports and exercise: ergogenic nutrients? Med Sport Sci 2013 59 18 28 https://doi.org/10.1159/000341937
- BescosR SuredaA TurJA PonsA The effect of nitric-oxide-related supplements on human performance Sports Med 2012 42 99 117 22260513 https://doi.org/10.2165/11596860-000000000-00000
- BendahanD MatteiJP GhattasB Confort-GounyS Le GuernME CozzonePJ Citrulline/malate promotes aerobic energy production in human exercising muscle Br J Sports Med 2002 36 282 289 1724533 1:STN:280:DC%2BD38zpsFyksQ%3D%3D 12145119 https://doi.org/10.1136/bjsm.36.4.282
- FigueroaA TrivinoJA Sanchez-GonzalezMA VicilF Oral L-citrulline supplementation attenuates blood pressure response to cold pressor test in young men Am J Hypertens 2010 23 12 16 1:CAS:528:DC%2BD1MXhsFKnsLfI 19851298 https://doi.org/10.1038/ajh.2009.195
- HicknerRC TannerCJ EvansCA ClarkPD HaddockA FortuneC GeddisH WaughW McCammonM L-citrulline reduces time to exhaustion and insulin response to a graded exercise test Med Sci Sports Exerc 2006 38 660 666 1:CAS:528:DC%2BD28Xktl2jtLk%3D 16679980 https://doi.org/10.1249/01.mss.0000210197.02576.da
- MeneguelloMO MendoncaJR LanchaAHJr Costa RosaLF Effect of arginine, ornithine and citrulline supplementation upon performance and metabolism of trained rats Cell Biochem Funct 2003 21 85 91 1:CAS:528:DC%2BD3sXhs1Sntrs%3D 12579527 https://doi.org/10.1002/cbf.1000
- NagayaN UematsuM OyaH SatoN SakamakiF KyotaniS UenoK NakanishiN YamagishiM MiyatakeK Short-term oral administration of L-arginine improves hemodynamics and exercise capacity in patients with precapillary pulmonary hypertension Am J Respir Crit Care Med 2001 163 887 891 1:STN:280:DC%2BD3M3ntFOmtQ%3D%3D 11282761 https://doi.org/10.1164/ajrccm.163.4.2007116
- Perez-GuisadoJ JakemanPM Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness J Strength Cond Res 2010 24 1215 1222 20386132 https://doi.org/10.1519/JSC.0b013e3181cb28e0
- SuredaA CordovaA FerrerMD PerezG TurJA PonsA L-citrulline-malate influence over branched chain amino acid utilization during exercise Eur J Appl Physiol 2010 110 341 351 1:CAS:528:DC%2BC3cXhtlWqsL3P 20499249 https://doi.org/10.1007/s00421-010-1509-4
- TakedaK MachidaM KoharaA OmiN TakemasaT Effects of citrulline supplementation on fatigue and exercise performance in mice J Nutr Sci Vitaminol (Tokyo) 2011 57 246 250 1:CAS:528:DC%2BC3MXovVyqtrs%3D https://doi.org/10.3177/jnsv.57.246
- KresslerJ Millard-StaffordM WarrenGL Quercetin and endurance exercise capacity: a systematic review and meta-analysis Med Sci Sports Exerc 2011 43 2396 2404 1:CAS:528:DC%2BC3MXhsV2mu7fN 21606866 https://doi.org/10.1249/MSS.0b013e31822495a7
- WuJ GaoW WeiJ YangJ PuL GuoC Quercetin alters energy metabolism in swimming mice Appl Physiol Nutr Metab 2012 37 912 922 1:CAS:528:DC%2BC38XpvFGmsLY%3D 22765761 https://doi.org/10.1139/h2012-064
- SharpMA HendricksonNR StaabJS McClungHL NindlBC Michniak-KohnBB Effects of short-term quercetin supplementation on soldier performance J Strength Cond Res 2012 26 Suppl 2 S53 60 22614228 https://doi.org/10.1519/JSC.0b013e31825cf22d
- O’FallonKS KaushikD Michniak-KohnB DunneCP ZambraskiEJ ClarksonPM Quercetin does not attenuate changes in markers of muscle function or inflammation after eccentric exercise Int J Sport Nutr Exerc Metab 2012
- KonradM NiemanDC HensonDA KennerlyKM JinF Wallner-LiebmannSJ The acute effect of ingesting a quercetin-based supplement on exercise-induced inflammation and immune changes in runners Int J Sport Nutr Exerc Metab 2011 21 338 346 1:CAS:528:DC%2BC3MXhtFKrtbjO 21813917
- AbbeyEL RankinJW Effect of quercetin supplementation on repeated-sprint performance, xanthine oxidase activity, and inflammation Int J Sport Nutr Exerc Metab 2011 21 91 96 1:CAS:528:DC%2BC3MXmtF2juro%3D 21558570
- NiemanDC WilliamsAS ShanelyRA JinF McAnultySR TriplettNT AustinMD HensonDA Quercetin’s influence on exercise performance and muscle mitochondrial biogenesis Med Sci Sports Exerc 2010 42 338 345 1:CAS:528:DC%2BC3cXpsVSntw%3D%3D 19927026 https://doi.org/10.1249/MSS.0b013e3181b18fa3
- GanioMS ArmstrongLE JohnsonEC KlauJF BallardKD Michniak-KohnB KaushikD MareshCM Effect of quercetin supplementation on maximal oxygen uptake in men and women J Sports Sci 2010 28 201 208 20054739 https://doi.org/10.1080/02640410903428558
- BigelmanKA FanEH ChapmanDP FreeseEC TrilkJL CuretonKJ Effects of six weeks of quercetin supplementation on physical performance in ROTC cadets Mil Med 2010 175 791 798 20968271 https://doi.org/10.7205/MILMED-D-09-00088
- UtterAC NiemanDC KangJ DumkeCL QuindryJC McAnultySR McAnultyLS Quercetin does not affect rating of perceived exertion in athletes during the Western States endurance run Res Sports Med 2009 17 71 83 19479626 https://doi.org/10.1080/15438620902901474
- DumkeCL NiemanDC UtterAC RigbyMD QuindryJC TriplettNT McAnultySR McAnultyLS Quercetin’s effect on cycling efficiency and substrate utilization Appl Physiol Nutr Metab 2009 34 993 1000 20029506 https://doi.org/10.1139/H09-099 1:CAS:528:DC%2BD1MXhsFymt7zN
- DavisJM MurphyEA CarmichaelMD DavisB Quercetin increases brain and muscle mitochondrial biogenesis and exercise tolerance Am J Physiol Regul Integr Comp Physiol 2009 296 R1071 1077 1:CAS:528:DC%2BD1MXkvVygurc%3D 19211721 https://doi.org/10.1152/ajpregu.90925.2008
- CuretonKJ TomporowskiPD SinghalA PasleyJD BigelmanKA LambourneK TrilkJL McCullyKK ArnaudMJ ZhaoQ Dietary quercetin supplementation is not ergogenic in untrained men J Appl Physiol 2009 107 1095 1104 1:CAS:528:DC%2BD1MXhtlGnsLzN 19679747 https://doi.org/10.1152/japplphysiol.00234.2009
- QuindryJC McAnultySR HudsonMB HosickP DumkeC McAnultyLS HensonD MorrowJD NiemanD Oral quercetin supplementation and blood oxidative capacity in response to ultramarathon competition Int J Sport Nutr Exerc Metab 2008 18 601 616 1:CAS:528:DC%2BD1MXhtVKhsbw%3D 19164830
- HensonD NiemanD DavisJM DumkeC GrossS MurphyA CarmichaelM JenkinsDP QuindryJ McAnultyS et al Post-160-km race illness rates and decreases in granulocyte respiratory burst and salivary IgA output are not countered by quercetin ingestion Int J Sports Med 2008 29 856 863 1:STN:280:DC%2BD1cjgs1Omuw%3D%3D 18213545 https://doi.org/10.1055/s-2007-989424
- NiemanDC HensonDA GrossSJ JenkinsDP DavisJM MurphyEA CarmichaelMD DumkeCL UtterAC McAnultySR et al Quercetin reduces illness but not immune perturbations after intensive exercise Med Sci Sports Exerc 2007 39 1561 1569 1:CAS:528:DC%2BD2sXpvFWgsro%3D 17805089 https://doi.org/10.1249/mss.0b013e318076b566
- NiemanDC HensonDA DavisJM Angela MurphyE JenkinsDP GrossSJ CarmichaelMD QuindryJC DumkeCL UtterAC et al Quercetin’s influence on exercise-induced changes in plasma cytokines and muscle and leukocyte cytokine mRNA J Appl Physiol 2007 103 1728 1735 1:CAS:528:DC%2BD2sXhtlyrtrzI 17717114 https://doi.org/10.1152/japplphysiol.00707.2007
- CampbellB DowningJ KilpatrickM La BountyP ElkinsA WilliamsS dos SantosMG The effects of a commercially available energy drink on resistance training and performance Med Sci Sports Exerc 2010 42 S315
- ForbesSC CandowDG LittleJP MagnusC ChilibeckPD Effect of Red Bull energy drink on repeated Wingate cycle performance and bench-press muscle endurance Int J Sport Nutr Exerc Metab 2007 17 433 444 1:CAS:528:DC%2BD2sXht1yktr%2FE 18046053
- HoffmanJR KangJ RatamessNA HoffmanMW TranchinaCP FaigenbaumAD Examination of a pre-exercise, high energy supplement on exercise performance J Int Soc Sports Nutr 2009 6 2 2621122 19126213 https://doi.org/10.1186/1550-2783-6-2
- CandowDG KleisingerAK GrenierS DorschKD Effect of sugar-free Red Bull energy drink on high-intensity run time-to-exhaustion in young adults J Strength Cond Res 2009 23 1271 1275 19528841 https://doi.org/10.1519/JSC.0b013e3181a026c2
- CuretonKJ WarrenGL Millard-StaffordML WingoJE TrilkJ BuyckxM Caffeinated sports drink: ergogenic effects and possible mechanisms Int J Sport Nutr Exerc Metab 2007 17 35 55 1:CAS:528:DC%2BD2sXjsFeks7k%3D 17460332
- AlfordC CoxH WescottR The effects of red bull energy drink on human performance and mood Amino Acids 2001 21 139 150 1:CAS:528:DC%2BD3MXotFKjs7c%3D 11665810 https://doi.org/10.1007/s007260170021
- CampbellB KilpatrickM WilbornC La BountyP ParkerB GomezB ElkinsA WilliamsS Dos SantosJA A commercially available energy drink does not improve peak power on multiple 20-second Wingate tests J Int Soc Sports Nutr 2010 7 P10 2951032 https://doi.org/10.1186/1550-2783-7-S1-P10
- GonzalezAM WalshAL RatamessNA KangJ HoffmanJR Effect of a pre-workout energy supplement on acute multi-joint resistance exercise J Sports Sci Med 2011 10 261 266 3761845 24149870
- AstorinoTA MateraAJ BasingerJ EvansM SchurmanT MarquezR Effects of red bull energy drink on repeated sprint performance in women athletes Amino Acids 2012 42 1803 1808 1:CAS:528:DC%2BC38XlsFert70%3D 21461905 https://doi.org/10.1007/s00726-011-0900-8
- HaffGG KochAJ PotteigerJA KuphalKE MageeLM GreenSB JakicicJJ Carbohydrate supplementation attenuates muscle glycogen loss during acute bouts of resistance exercise Int J Sport Nutr Exerc Metab 2000 10 326 339 1:CAS:528:DC%2BD3cXntlyks74%3D 10997956
- KulikJR TouchberryCD KawamoriN BlumertPA CrumAJ HaffGG Supplemental carbohydrate ingestion does not improve performance of high-intensity resistance exercise J Strength Cond Res 2008 22 1101 1107 18545201 https://doi.org/10.1519/JSC.0b013e31816d679b
- LambertCP FlynnMG BooneJBJr MichaudTJ Rodriguez-ZayasJ Effects of carbohydrate feeding on multiple bout resistance exercised J Appl Sport Sci Res 1991 5 192 197
- WalshAL GonzalezAM RatamessNA KangJ HoffmanJR Improved time to exhaustion following ingestion of the energy drink Amino Impact J Int Soc Sports Nutr 2010 7 14 2861014 20398312 https://doi.org/10.1186/1550-2783-7-14 1:CAS:528:DC%2BC3cXlsVyrtrc%3D
- CurrellK JeukendrupAE Validity, reliability and sensitivity of measures of sporting performance Sports Med 2008 38 297 316 18348590 https://doi.org/10.2165/00007256-200838040-00003
- LaursenPB FrancisGT AbbissCR NewtonMJ NosakaK Reliability of time-to-exhaustion versus time-trial running tests in runners Med Sci Sports Exerc 2007 39 1374 1379 17762371 https://doi.org/10.1249/mss.0b013e31806010f5
- ScholeyAB KennedyDO Cognitive and physiological effects of an “energy drink”: an evaluation of the whole drink and of glucose, caffeine and herbal flavouring fractions Psychopharmacology (Berl) 2004 176 320 330 1:CAS:528:DC%2BD2cXps1Wqur8%3D https://doi.org/10.1007/s00213-004-1935-2
- SmitHJ CottonJR HughesSC RogersPJ Mood and cognitive performance effects of “energy” drink constituents: caffeine, glucose and carbonation Nutr Neurosci 2004 7 127 139 1:CAS:528:DC%2BD2cXps12jsLw%3D 15526987 https://doi.org/10.1080/10284150400003041
- RaoA HuH NobreAC The effects of combined caffeine and glucose drinks on attention in the human brain Nutr Neurosci 2005 8 141 153 1:CAS:528:DC%2BD2MXpslyku70%3D 16117181 https://doi.org/10.1080/10284150500096994
- HowardMA MarczinskiCA Acute effects of a glucose energy drink on behavioral control Exp Clin Psychopharmacol 2010 18 553 561 1:CAS:528:DC%2BC3MXht1antLY%3D 21186930 https://doi.org/10.1037/a0021740
- PettittRW NiemeyerJD SextonPJ LipetzkyA MurraySR Do the non-caffeine ingredients of energy drinks affect metabolic responses to heavy exercise? J Strength Cond Res 2012 [Epub ahead of print].
- BloomerRJ Fisher-WellmanKH HammondKG SchillingBK WeberAA ColeBJ Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men J Int Soc Sports Nutr 2009 6 4 2645359 19175919 https://doi.org/10.1186/1550-2783-6-4 1:CAS:528:DC%2BC3cXksVKitb4%3D
- DullooAG GeisslerCA HortonT CollinsA MillerDS Normal caffeine consumption: influence on thermogenesis and daily energy expenditure in lean and postobese human volunteers Am J Clin Nutr 1989 49 44 50 1:CAS:528:DyaL1MXovVelsA%3D%3D 2912010
- JitomirJ NassarE CulbertsonJ MoreillonJ BufordT HudsonG CookeM KreiderR WilloughbyDS The acute effects of the thermogenic supplement Meltdown on energy expenditure, fat oxidation, and hemodynamic responses in young, healthy males J Int Soc Sports Nutr 2008 5 23 2637826 19087290 https://doi.org/10.1186/1550-2783-5-23 1:CAS:528:DC%2BC3cXksVKitLc%3D
- MendelRW HofheinsJE Metabolic responses to the acute ingestion of two commercially available carbonated beverages: a pilot study J Int Soc Sports Nutr 2007 4 7 2034594 17908290 https://doi.org/10.1186/1550-2783-4-7
- RudelleS FerruzziMG CristianiI MoulinJ MaceK AchesonKJ TappyL Effect of a thermogenic beverage on 24-hour energy metabolism in humans Obesity (Silver Spring) 2007 15 349 355 1:CAS:528:DC%2BD2sXosVamtbw%3D https://doi.org/10.1038/oby.2007.529
- TaylorLW WilbornCD HarveyT WismannJ WilloughbyDS Acute effects of ingesting Java Fittrade mark energy extreme functional coffee on resting energy expenditure and hemodynamic responses in male and female coffee drinkers J Int Soc Sports Nutr 2007 4 10 2098780 17919327 https://doi.org/10.1186/1550-2783-4-10
- WilbornC TaylorL PooleC BusheyB WilliamsL FosterC CampbellB Effects of ingesting a commercial thermogenic product on hemodynamic function and energy expenditure at rest in males and females Appl Physiol Nutr Metab 2009 34 1073 1078 20029516 https://doi.org/10.1139/H09-113 1:CAS:528:DC%2BD1MXhsFymt7zP
- RobertsMD DalboVJ HassellSE StoutJR KerksickCM Efficacy and safety of a popular thermogenic drink after 28 days of ingestion J Int Soc Sports Nutr 2008 5 19 2579279 18950510 https://doi.org/10.1186/1550-2783-5-19 1:CAS:528:DC%2BC3cXksVKitLw%3D
- DalboVJ RobertsMD StoutJR KerksickCM Acute effects of ingesting a commercial thermogenic drink on changes in energy expenditure and markers of lipolysis J Int Soc Sports Nutr 2008 5 6 2276475 18289388 https://doi.org/10.1186/1550-2783-5-6 1:CAS:528:DC%2BC3cXksVKit70%3D
- DalboVJ RobertsMD StoutJR KerksickCM Effect of gender on the metabolic impact of a commercially available thermogenic drink J Strength Cond Res 2010 24 1633 1642 20508469 https://doi.org/10.1519/JSC.0b013e3181db9bbd
- RashtiSL RatamessNA KangJ FaigenbaumAD ChilakosA HoffmanJR Thermogenic effect of meltdown RTD energy drink in young healthy women: a double blind, cross-over design study Lipids Health Dis 2009 8 57 2803475 20017916 https://doi.org/10.1186/1476-511X-8-57 1:CAS:528:DC%2BD1MXhsF2gurnO
- BloomerRJ CanaleRE BlankenshipMM HammondKG Fisher-WellmanKH SchillingBK Effect of the dietary supplement Meltdown on catecholamine secretion, markers of lipolysis, and metabolic rate in men and women: a randomized, placebo controlled, cross-over study Lipids Health Dis 2009 8 32 2728713 19656409 https://doi.org/10.1186/1476-511X-8-32 1:CAS:528:DC%2BD1MXhtVSksrjP
- StoutJ MoonJ TobkinS LockwoodC SmithA GraefJ KendallK BeckT CramerJ Pre-workout consumption of Celsius(R) enhances the benefits of chronic exercise on body composition and cardiorespiratory fitness J Int Soc Sports Nutr 2008 5 P8 3313119 https://doi.org/10.1186/1550-2783-5-S1-P8
- HigginsJP TuttleTD HigginsCL Energy beverages: content and safety Mayo Clin Proc 2010 85 1033 1041 2966367 1:CAS:528:DC%2BC3MXpt1yku7k%3D 21037046 https://doi.org/10.4065/mcp.2010.0381
- SepkowitzKA Energy drinks and caffeine-related adverse effects JAMA 2012 1 2 [Epub ahead of print]
- TorpyJM LivingstonEH Energy drinks JAMA 2012 1 1 [Epub ahead of print]
- HowlandJRDJ Risks of energy drinks mixed with alcohol JAMA 2012 1 2 [Epub ahead of print]
- ClausonKA ShieldsKM McQueenCE PersadN Safety issues associated with commercially available energy drinks J Am Pharm Assoc (2003) 2008 48 e55 63 https://doi.org/10.1331/JAPhA.2008.07055 quiz e64-57
- DuchanE PatelND FeuchtC Energy drinks: a review of use and safety for athletes Phys Sportsmed 2010 38 171 179 20631477 https://doi.org/10.3810/psm.2010.06.1796
- LockwoodCM MoonJR SmithAE TobkinSE KendallKL GraefJL CramerJT StoutJR Low-calorie energy drink improves physiological response to exercise in previously sedentary men: a placebo-controlled efficacy and safety study J Strength Cond Res 2010 24 2227 2238 19816213 https://doi.org/10.1519/JSC.0b013e3181aeb0cf
- PenningtonN JohnsonM DelaneyE BlankenshipMB Energy drinks: a new health hazard for adolescents J Sch Nurs 2010 26 352 359 20538866 https://doi.org/10.1177/1059840510374188
- WeissEP ArifH VillarealDT MarzettiE HolloszyJO Endothelial function after high-sugar-food ingestion improves with endurance exercise performed on the previous day Am J Clin Nutr 2008 88 51 57 2585377 1:CAS:528:DC%2BD1cXoslylsL8%3D 18614723
- PetitA LevyF LejoyeuxM ReynaudM KarilaL Energy drinks: an unknown risk Rev Prat 2012 62 673 678 22730801
- Why isn’t the amount of caffeine a product contains required of a food label?.http://www.fda.gov/AboutFDA/Transparency/Basics/ucm194317.htm,
- Health Canada’s proposed approach to managing caffeinated energy drinks.http://www.hc-sc.gc.ca/fn-an/legislation/pol/energy-drinks-boissons-energisantes-eng.php,
- McCuskerRR GoldbergerBA ConeEJ Caffeine content of specialty coffees J Anal Toxicol 2003 27 520 522 1:CAS:528:DC%2BD3sXos1Gksrg%3D 14607010 https://doi.org/10.1093/jat/27.7.520
- JinKN ChunEJ LeeCH KimJA LeeMS ChoiSI Subclinical coronary atherosclerosis in young adults: prevalence, characteristics, predictors with coronary computed tomography angiography Int J Cardiovasc Imaging 2012 [Epub ahead of print]
- ThieneG CarturanE CorradoD BassoC Prevention of sudden cardiac death in the young and in athletes: dream or reality? Cardiovasc Pathol 2010 19 207 217 19535269 https://doi.org/10.1016/j.carpath.2009.04.001
- RadojevicN BjelogrlicB AleksicV RancicN SamardzicM PetkovicS SavicS Forensic aspects of water intoxication: four case reports and review of relevant literature Forensic Sci Int 2012 220 1 5 1:CAS:528:DC%2BC38XptFansbs%3D 22306188 https://doi.org/10.1016/j.forsciint.2012.01.021
- HolmgrenP Norden-PetterssonL AhlnerJ Caffeine fatalities–four case reports Forensic Sci Int 2004 139 71 73 1:CAS:528:DC%2BD3sXpvVWqs7w%3D 14687776 https://doi.org/10.1016/j.forsciint.2003.09.019
- KerriganS LindseyT Fatal caffeine overdose: two case reports Forensic Sci Int 2005 153 67 69 1:CAS:528:DC%2BD2MXmsVWltL4%3D 15935584 https://doi.org/10.1016/j.forsciint.2005.04.016
- RudolphT KnudsenK A case of fatal caffeine poisoning Acta Anaesthesiol Scand 2010 54 521 523 1:STN:280:DC%2BC3c3osVOgtw%3D%3D 20096021 https://doi.org/10.1111/j.1399-6576.2009.02201.x
- NawrotP JordanS EastwoodJ RotsteinJ HugenholtzA FeeleyM Effects of caffeine on human health Food Addit Contam 2003 20 1 30 1:CAS:528:DC%2BD3sXhvFOktQ%3D%3D 12519715 https://doi.org/10.1080/0265203021000007840
- HigdonJV FreiB Coffee and health: a review of recent human research Crit Rev Food Sci Nutr 2006 46 101 123 1:CAS:528:DC%2BD28XhvVWqt70%3D 16507475 https://doi.org/10.1080/10408390500400009
- UsmanA JawaidA Hypertension in a young boy: an energy drink effect BMC Res Notes 2012 5 591 3507669 23106965 https://doi.org/10.1186/1756-0500-5-591
- WorthleyMI PrabhuA De SciscioP SchultzC SandersP WilloughbySR Detrimental effects of energy drink consumption on platelet and endothelial function Am J Med 2010 123 184 187 1:CAS:528:DC%2BC3cXpsleksw%3D%3D 20103032 https://doi.org/10.1016/j.amjmed.2009.09.013
- SteinkeL LanfearDE DhanapalV KalusJS Effect of “energy drink” consumption on hemodynamic and electrocardiographic parameters in healthy young adults Ann Pharmacother 2009 43 596 602 19299320 https://doi.org/10.1345/aph.1L614
- Adverse event reporting for dietary supplements: an inadequate safety valve.https://oig.hhs.gov/oei/reports/oei-01-00-00180.pdf,