“Energy Drinks” Implications for Student Athletes and Athletic Departments
The worldwide “energy drink” market has grown exponentially in the last decade. The primary targets of the industry’s marketing campaigns are young adults and as a result, university and college athletes are frequent consumers of these products. The effects of these beverages can be quite significant therefore their use by student athletes requires analysis. Athletic departments and coaches need to be cognizant of current trends and knowledgeable about the potential effects that these beverages may have on student athletes. In addition to this, they should also be able to provide direction to their athletes regarding the use of these drinks.
What is the consumption level of energy drinks by student athletes in the college and university setting and for what is the purpose in the utilization of these beverages? Are they aware of the contents of the energy drinks or understanding of the potential positive and negative aspects of their intake?
The topic is important for the overall wellness of student athletes. For that reason, knowledge of the issues regarding energy drink consumption is essential for coaches and athletic administrators. With the goal of improving performance, elite athletes often consider a variety of options to achieve goals, one of which may be to incorporate energy drinks into their training regime. Caffeine is the main ingredient in energy drinks and its ability to enhance performance under certain conditions has been well documented. Many of the marketing campaigns explicitly state that the beverage will improve functioning; inferring the likelihood that that their use will boost athletic performance.
Earlier research has indicated that to a greater extent than regular students, student athletes display a propensity to engage in “binge drinking”. This, in the context of energy drink consumption becomes a twofold concern, as it has become common practice to consume energy drinks as an alcoholic cocktail mix. The combination of alcohol and caffeine work to promote an increase in alcohol consumption resulting in greater levels of intoxication which can lead to serious consequences for the drinker.
Review of Literature
What is an Energy Drink?
With catchy slogans, exotic names and expensive marketing campaigns, energy drinks entered into the North American beverage market and now enjoy a significant portion of the industry. Energy drinks are now commonly sold alongside soft drinks in vending machines, convenience stores and on grocery store shelves. In addition to providing a boost of energy, companies have marketed their products as promoting wellness through their medicinal properties, as many usually contain vitamins and ingredients such as ginseng, guarana and taurine. In 2005 these claims prompted Health Canada to state, “energy drinks are meant to supply mental and physical stimulation for a short period of time” (Background section, para. 2). Regardless of their intended use or the purported benefits, energy drinks are now consumed for a variety of reasons which has grown to include: energy booster, thirst quencher, cocktail mix and they are constantly pioneering new applications such as the flavoring in popular beverages such as smoothies.
The term energy drink conveys a connection to activity; therefore, the uninformed consumer may assume that there is an inference to the benefits of consuming these drinks during physical exercise. This presumption is further reinforced on retail shelves as energy drinks are also typically located adjacent to traditional sport drinks such as Gatorade or Powerade, thus serving to further imply a positive relationship between their use and exercise. Caffeine, the central ingredient of energy drinks, has been well researched but the potential for use as a performance enhancer is at best questionable when considering the variance in individual tolerance to the drug and the accompanying range of possible adverse effects (Janzen, 2008).
The concept of energy drinks is not new as, given that the primary component of energy drinks is a high level of caffeine. Jolt Cola, the precursor to the current phenomena was first distributed in the 1980’s (Retelny, 2007). Although the current field of energy drinks are now marketed as a health product with medicinal ingredients; the beverage is laden with caffeine. First introduced in the United States in 1997, “Red Bull” was the forerunner of the modern energy drink and still remains as the most recognizable brand in the industry (Retelny, 2007). However, it now has considerable competition in the marketplace as five hundred new energy drinks were introduced to the worldwide market in 2006 (Fornicola, 2007). According to Cohen (2008) marketing research firm A.C. Nielsen indicated that worldwide sales rose from 3.5 billion dollars in 2006 to 4.7 billion in 2007. This speaks volumes for its profitability and potential markets as many companies continue to introduce new products to capture a share of a growing consumer base as the marketing of these products appear to be focused on the discretionary spending a of specific demographic group; young teens to young adults. In a bid to remain competitive, manufacturers continue to push the boundaries and are producing drinks that contain an increasing complexity of the “medicinal” ingredients, with higher levels of caffeine and an increase in the serving size (Fornicola, 2007).
Content labeling remains inconsistent across North American and is further complicated by the steady stream of new products into the energy drink market. The proliferation and popularity of these drinks have clearly caught the regulating agencies like Health Canada off guard and by all accounts, as they were ill equipped to respond to the initial claims purported by the various producers. In Canada, most energy drinks are now approved as “Natural Health Products”. This in itself is a controversial decision that was a result of the establishment of Health Canada’s Natural Health Products Directorate that began in 2004 (CBC, 2005). According to Marsden (as cited in CBC Marketplace, 2005) from the Ontario Association of Naturopathic Doctors: “Red Bull is more like sin in a tin, and makes a mockery of what he considers to be natural health products” (p. 2). However, the significance of this designation means detailed labeling is required that includes the amounts of medicinal ingredients, non-medicinal ingredients, recommended uses, doses as well as cautions.
In the United States, however, “the Food and Drug Administration (FDA) regulates the caffeine content in soft drinks but not in energy drinks” (Cohen, 2008, anxiety attack section, para. 9). The FDA could challenge the caffeine content in energy drinks but has typically not done so unless the amount of caffeine is greater than would be consumed from an average cup of coffee (Cohen, 2008). Manufacturers are not required to list ingredients in the United States, therefore it is very difficult for consumers to appreciate the amounts of caffeine ingested. This information can usually be located on the company websites but it is unlikely that consumers would typically be concerned enough about the composition of the product to visit the website as most take it for granted that the product is safe simply because it is on the shelves of food stores. While ingredient information is typically not listed on the products in the United States, some warning labels are present. However, these only provide information regarding recommendations of use.
The variety in the energy drink market makes a complete review of contents a daunting task. Sugar (glucose, sucrose, fructose, etc.) is found in most products and the effects of sugar are well known, but sugar-free varieties are now being consumed in significant numbers. Malinaukas, Aeby, Overton, Carpenter-Aeby, and Barber-Heidal (2007) found that 26% of college student energy drink users chose sugar-free versions with significantly more females than males opting for the low calorie choice. While many exotic components are found in various brands of energy drinks, it appears that there are four ingredients central to the majority of the marketed products: caffeine, taurine, glucuronolactone and vitamins.
The primary ingredient of energy drinks is the drug caffeine. Janzen (2008) states: “Caffeine is a stimulant which has been scientifically shown to increase heart rate and blood pressure, thereby increasing alertness and enhancing performance of certain tasks when consumed in small doses. “ (p. 1). In 2004, caffeine was removed from the restricted substances list of the World Anti-Doping Agency (WADA) but remains on WADA’s monitoring program (Desbrow & Leveritt, 2007). WADA’s decision implies that the performance enhancing ability of caffeine is limited and it appears that most research confirms just that; in that limited quantities, caffeine can improve mood and cognitive performance (Scholey & Kennedy, 2004). But, at high levels of consumption, many negative effects can materialize. As a result, caffeine’s beneficial effect on athletic performance is not universally accepted.
Janzen (2008) indicates that Red Bull contains 80 mg of caffeine in its 250 ml can while the concentration in caffeinated soft drinks ranges from 29-55 mg per 355 ml serving. Although it can vary, coffee typically contains 100 mg of caffeine in a 250 ml serving (Fornicola, 2007). Many popular energy drinks, such as Monster, Full Throttle and Rockstar contain similar concentrations of caffeine to Red Bull. However, in attempting to create a unique product some manufactures have created niche market energy drinks with significantly higher amounts of caffeine. The McLatchy – Tribune Business News (2008) identifies three drinks with extremely high caffeine levels: Boo-Koo Energy, 24 oz., 360 mg; Wired X344, 16 oz., 344 mg; Fixx, 20 oz., 344 mg” (para. 9).
When used in moderation the effects of caffeine are rarely visible. The acceptance and utilization of caffeine in our modern society is commonplace. The majority of caffeine is consumed in the morning via coffee to improve mood and produces no ill effects. However, many negative consequences of excess caffeine consumption have been identified and certain segments of the population are at particular risk. The negative effects of caffeine can become severe for people who are caffeine sensitive and in children who are usually of lower body weight than adults. In comparison to hot coffee, which is normally drank slowly; energy drinks may taste good, are cold and can be consumed quickly (Fornicola, 2007). This provides an opportunity for an injection of a high dose of caffeine to enter the body in a short period of time. High doses of caffeine can negatively affect concentration, attention, and behavior; produce irregular heartbeats, cause nausea, restlessness, headache and dehydration (Griffith, 2008). Energy drinks are also expensive compared to healthier alternatives such as juice, milk or water. Given the increased use and the negative outcomes for children it is not surprising that school officials are also becoming concerned about the availability of energy drinks to their students.
After caffeine, the most widely used, but perhaps least understood substance in energy drinks is taurine. Taurine is an amino acid that the body replenishes on its own” (Lidz, 2003). It is important in several metabolic processes and may have some anti-oxidant properties (CBC Marketplace, 2005). Typical human intake is about 60 mg per day (Laquale, 2007). A single serving of Red Bull contains 1000 mg of taurine. Most other energy drink manufacturers include similar amounts of taurine in their products. A 473 ml serving of “Monster” contains 2000 mg while the same sized container of “Rock Star” includes 1894 mg of taurine.
Energy drink manufacturers imply that a special synergy exists between all the ingredients and certainly; taurine would be identified as having a key part of that position. Laquale (2007) challenges that notion by suggesting that the benefits of taurine are only based on testing done on house cats from the 1970’s. The taurine contained in Red Bull has been promoted as both its secret and controversial ingredient. This was responsible for Red Bull’s delay and acceptance in many countries, including Canada where until recently to sell the product was deemed illegal (CBC Marketplace, 2005). Research into the effects of taurine is limited and inconclusive. Lidz (2003) states that, “the company itself admits that taurine’s main function is simply that of flavor enhancer” (p. 12). The German Institute for the Protection of Consumer Health suggests that claims of taurine’s value are misleading (Lidz, 2003). Alford et al indicated that Red Bull did improve aerobic endurance and anaerobic performance (Laquale, 2007). However, it was not determined whether the results were due to caffeine, taurine or a combination of all ingredients (Laquale, 2007). Griffiths states that consumers are being misled and that the effects of the drinks are dependent of the level of caffeine (Laquale, 2007). At this point, there is simply not enough research that has been done to substantiate a positive effect for taurine much less to investigate any potential long-term effects of consuming the high doses of taurine that are present in energy drinks.
Glucuronolactone is a carbohydrate that occurs naturally in the body and like taurine is suspected to detoxify the body (CBC, 2005). Red Bull includes glucuronolactone to increase energy and feelings of well being (Laquale, 2007). Not surprisingly, the hundreds of energy drink brands that have come on the market since the introduction of Red Bull also contain this substance. Laquale suggests that glucuronolactone has received notoriety due to undocumented reports that it was provided to American soldiers during the Vietnam War to provide energy, but was banned due to brain tumor related deaths. However, research to date has focused on animals making the effects on humans difficult to assess (CBC, 2005).
An assortment of B vitamins: B2 - riboflavin, B3 – niacin, B6 and B12 are the last ingredients common to the majority of energy drinks. While their importance to healthy living is undeniable, it would seem appropriate for ingestion to occur through a healthy balanced diet and not as a supplement of an energy drink.
Malinauskas et al. (2007) states that energy drinks are intended for young adults but little formal research has occurred to accurately describe the clientele of the multi-billion dollar business. Malinauskas et al. studied the consumption pattern of college students finding that 51% are energy drink users, meaning they had consumed more than one energy drink, per month, in the semester they were questioned. In Canada, energy drinks labeled as natural health products must identify cautions that comply with Health Canada’s Natural Health Products Directorate. These beverages are not recommended for: breastfeeding or pregnant women, caffeine sensitive persons or children. Product labeling also advises against mixing the beverage with alcohol and states a maximum daily dose. An analysis of the cautions listed on three popular energy drinks were found to all deliver the same messages except for the maximum daily dose. Red Bull and Rock Star advise to not exceed 500 ml per day while Monster’s advice allows 1000 ml per day.
While it is unclear how many adults are consuming energy drinks it is certain that, despite the warnings, many children are regular consumers. The Florida Poison Control Center has started to track cases of caffeine overexposure after 39 people ages 2 to 20 presented symptoms from January 2007 to March 2008 (Cohen, 2008). A school nurse in California sent three students to hospital by ambulance in the past year due to irregular heart rates brought on by consumption of energy drinks (Dorsey, 2008). Although energy drinks are not marketed directly to children and adolescents, it is clear that this age group contributes significantly to the total market. Energy drinks are not recommended for children but surprisingly there is currently no restriction on children purchasing them even though the effects of the caffeine due to body size and tolerance are more pronounced in children than in adults. As a result, some schools have banned the drinks from school property and many jurisdictions are contemplating trying to restrict their sale to children altogether. Also, studies suggest those with high blood pressure or heart disease should avoid energy drinks. The American Heart Association issued an alert in November, 2007 warning consumers about the dangers of consumption for those with known cardiovascular issues (Lofshult, 2008).
Energy drinks are marketed with colorful descriptions and provocative names that make them sound fun and exciting. Rockstar, Monster, Full Throttle, Throw Down and Sobe No Fear are just a sample of the inviting names that fill the store shelves. Marketing slogans are developed to stimulate interest in the product and distinguish themselves from the competition: “Get Spiked”, “Party like a Rockstar”, and “Feel the Freak” are just a sample of the slogans and marketing strategies of the energy drink companies. More notably the language and image targeted in the advertising are not directed to adults. If anything the marketing of these products remove the ambiguity and remove all doubt as to whom these products are intended for; teens and young adults.
Red Bull remains the leader in energy drink sales with 40% of the market share (Agri-Food Trade Service, 2008) and not surprisingly the “Red Bull gives you wings” slogan is very recognizable. Red Bull developed its image over the past decade by sponsorship of extreme sports and targeting of college age students (Lidz, 2003). Clearly, their message is that one who consumes Red Bull is living life to the fullest and to the edge. Many have been enticed into the fashion of the Red Bull “It is not a drink, it is a lifestyle” (Red Bull, 2008) campaign and contributed to the company’s success. Red Bull’s marketing campaign, more than other brands, has created a connection to sport and fitness with the implication that one will achieve greater performance in athletics by using their product. The phrase “Vitalizes body and mind” is found on Red Bull’s current containers. Lidz (2003) identified other slogans that have been associated with Red Bull including: “increases concentration”, “improves reaction speed”, “stimulates metabolism” and “Red Bull’s effects have been recognized by world-class athletes”. Miller (2008) suggests others have copied Red Bull’s strategy as, “Energy drink advertising consistently emphasizes a physically active lifestyle featuring a range of extreme sports…” (p. 481). Miller goes on to suggest that the marketing strategies are similar to those used to sell tobacco and alcohol to youths (p. 488). This is incongruent with promotion of energy drinks as healthy natural products.
The long-term effects of energy drink consumption are unknown. Many studies have analyzed the extended use of caffeine with mixed results, although the moderate use of caffeine is commonly accepted to pose little health risk to individuals. Fornicola (2007) indicates that adults consume on average 200 mg per day which equates to about two cups of coffee. Although caffeine is undoubtedly the greatest contributor to the effects that energy drinks produce, the fact remains that there is no research into possible problems associated with long-term ingestion of the high concentrations of taurine or glucuronolactone.
The Red Bull Company (2008), states that the short-term positive effects of Red Bull and its combination of ingredients are proven by academic studies and are publicly available. However, they do not provide any direction or links to those studies. The majority of current research clearly disputes those claims while recognizing the effects of caffeine in that the short-term effects of increased energy are quantifiable and have been primarily attributed to caffeine (Malinauskas et al., 2007).
There remains considerable concern regarding the negative effects of energy drinks. Emergency room visits from effects of energy drink consumption are becoming commonplace. Child Health Alert (2008) reports on one such incident when a 23 year old was hospitalized with a dangerously high heart rate after consuming the energy drink GNC Speed Shot followed by a Mountain Dew soft drink which also contains caffeine. As indicated in the Child Heart Alert article, the GNC Speed Shot website itself warns against using their product with others that contain caffeine. Numerous countries including France, Denmark and Norway still ban the sale of Red Bull and some high profile deaths linked to energy drinks fuel an ongoing suspicion. One such tragedy occurred when a healthy 18 year old Irish basketball player collapsed from cardiac arrest after consuming four cans of Red Bull’s prior to the game (Laquale, 2007).
As previously stated, Malinauskas et al. (2007) found that 51% of college students consume energy drinks. Logic would dictate that student athletes in college and university would consume the product in similar or even greater numbers due to the connection of sport and energy drinks created by the industry. Promotional statements for Red Bull suggest that their product be consumed prior to demanding athletic contests, races and sport games (Red Bull energy drink, 2008). Miller (2008) confirmed the presence of phenomena labeled ‘Toxic Jock Identity’, “defined as a sport-related identity predicated on risk taking and hyper masculinity” (p. 481) in association with energy drink consumption. An increase in compromising behavior could be a result of toxic jock identity and consumption of energy drinks could be a predictor of the phenomena (Miller, 2008). The temptation to improve athletic performance and conform to the athletic identity could influence student athletes to be greater consumers of energy drinks compared to the general student body.
Does ingestion of an energy drink really boost athletic performance? Caffeine is the only ingredient in energy drinks that has been studied in depth and has proven effects. The short and long term effects of consuming high doses of taurine and glucuronolactone require additional study. Athletes have used caffeine prior to competition and training for years. However, the fact remains that to date the drug is still not well understood by most athletes. The literature also provides mixed messages regarding the performance enhancing capability of caffeine and the value in consuming it prior to exercise. Fornicola (2007) states that there is no need to use energy drinks to gain an advantage and that catching a quick caffeine fix is not very intelligent. Janzen (2008) indicates that endurance athletes successfully use caffeine’s ability to utilize fat as an energy source early in competition leaving greater amounts of muscle glycogen to be available later on. However, Janzen also stated that “4% dehydration equals 20% of performance lost” (pg. 1). As caffeine also leads to dehydration, the amount necessary to enhance performance has to be very precise. Desbrow and Levitt (2007) demonstrated that the majority of elite level triathlon athletes use caffeine to improve physical performance and concentration. However, athlete knowledge of caffeine containing products and amounts was limited (Desbrow and Levitt). Umana-Alvarado and Moncada-Jimenez (2005) conducted a study on the effects of energy drink consumption on male athletes and aerobic activity. No significant difference was found between the control group and the placebo group but, those that had consumed energy drinks had a lower perceived exertion. As caffeine is a diuretic, it also has the capacity to further the level of dehydration that athletes will encounter during competition. Even Red Bull Company itself acknowledges this and encourages individuals to drink lots of water during exercise (Red Bull, 2008).
Alcohol mixed with energy drinks
Studies have shown student athletes are prone to binge drinking at higher rates than the average student. Grossman, Wechsler, Davenport, and Dowdall (1997) found college athletes engaged in binge drinking and used chewing tobacco at greater rates than non-athletes but were less likely to smoke cigarettes or marijuana. Additional research indicates those involved in team sports are even more likely to engage in high risk alcohol consumption (Brenner and Swanik, 2007). When the current trend of mixing energy drinks and alcohol is assessed, athletes may be particularly at risk.
Although many of the energy drink companies provide cautions against mixing energy drinks and alcohol, it is clearly very popular to do so. Miller (2008) indicated that the website Drinknation.com contained 201 Red Bull based alcohol recipes alone. Even though the Red Bull label advises to not mix Red Bull with alcohol, the company continues to glamorize the combination on their website when it states that Red Bull can be used for more than non-stop partying (Red Bull, 2008).
The effect of combining alcohol and energy drinks lessens subjective intoxication (O’Brien et al., 2008). This means an individual may consume more alcohol than usual as they believe themselves to be less intoxicated. They may also not feel the fatigue, due to the effects of caffeine; that would normally limit alcohol consumption (Dunlap, 2008).
The combination of a depressant (alcohol) and stimulant (energy drink) clearly has the potential to exacerbate typical issues surrounding alcohol consumption. This situation, combined with the tendency of student athletes to binge drink should raise concern. O’Brien et al. (2008) indicated “students who reported consuming alcohol mixed with energy drinks had significantly higher prevalence of alcohol–related consequence, including being taken advantage of sexually, taking advantage of another sexually, riding with an intoxicated driver, being physically hurt or injured, and requiring medical treatment” (p. 453). Further, the U.S. Surgeon General reported that close to 5000 people under the age of 21 die each year in the United States due to alcohol related injuries (Dunlap, 2008).
Students have used caffeine to stay awake for study purposes long before the infiltration of energy drinks. The available selection of these beverages allows students that may not like coffee to obtain a more palatable source of caffeine. If used in moderation, consumption of energy drinks to aid the learning process would appear to be a harmless event. In the context of educating student athletes, knowledge of the negative effects of excess caffeine need to be detailed to assist them in making appropriate choices in all situations which includes for studying purposes. Coaches and athletic directors need to provide information to student athletes to assist them in making responsible choices in situations that are presented to them.
The casual consumption of energy drinks has been the most significant reason for the rapid rise in popularity. They are now available everywhere and it is common for someone to select an energy drink in place of a soft drink or coffee. The market seems poised for continued expansion with aggressive marketing meaning their use will become even more common and accepted by society. Unless provided with the information necessary to make the best choices to enhance athletic performance and personal health, student athletes will correspondingly follow and increase their consumption patterns of energy drinks.
Summary and Conclusions
Given the proliferation in consumption of energy drinks, the potential for significant use by student athletes and the possible negative effects resulting form energy drink abuse, coaches and athletic departments should take more initiative in educating their athletes on this issue. The energy drink companies have aggressively marketed their products to college students and continue to advertise the benefits of consuming these beverages. This places significant influence on students to be an energy drink consumer and for the uniformed student athlete the results may possess negative consequences.
While the purported benefits of the taurine and glucuronolactone found in energy drinks are unproven, the potential positive and negative effects of caffeine are well documented. The choice to use caffeine prior to training or competition needs to be a personal one based on knowledge of the pros and cons, as well as past experience with caffeine. Student athletes should be encouraged to use caffeine in moderation and also be provided with information regarding the concentrations in various food and beverages so that caffeine intake can be monitored. The fact is that most energy drinks do not contain more caffeine than a cup of coffee, although there is a noticeable trend as serving size has been steadily increasing. If consuming an energy drink before a competition improves mood and concentration it would be difficult to suggest that it poses significant danger. The negative effects of caffeine will likely only become evident if intake becomes considerably higher or if the user is caffeine sensitive. Although there have been deaths associated with energy drink consumption and sport, they seem to be isolated cases involving multiple servings and with high levels of caffeine.
While providing accurate information to athletes regarding the use of energy drinks and caffeine as it relates to athletic performance is important, the greater concern for athletic departments should be with the combination of alcohol and energy drinks. A typical pattern exists of athletes consuming alcohol after a game when they are already dehydrated. This could be a recipe for disaster when adding in the double diuretic effect of the caffeine in energy drinks combined with the diuretic properties of alcohol. Further, the masking of intoxication that caffeine provides promotes greater alcohol consumption, which leads to severe consequences as it is common for young adults to make poor choices after consuming alcohol, often with negative to disastrous results. The growing trend of mixing alcohol with energy drinks is likely to lead to increased intoxication followed by impaired judgment, more poor choices and negative consequences. Patterns of energy drink consumption are still increasing therefore athletes need to be better informed of the dangers of engaging in this practice. Athlete education on all aspects of energy drink and caffeine consumption needs to become a priority for athletic departments to ensure the wellness and safety of their athletes.
Agri-Food Trade Service (January 2008). The Energy Drink Segment in North America Retrieved July 10, 2008 from http://www.ats.agr.gc.ca/us/4387_e.htm
Brenner, J. & Swanik, N. (2007) High-Risk Drinking Characteristics in Collegiate Athletes. Journal of American College Health, 56(3), 267.
Caffeine—Watch Out For “Energy Drinks”. (2008) Child Health Alert. Professional Development Collection. 26, 2-3.
CBC Marketplace (2005). Raging Bull: Health warnings over popular energy drink being brushed off? Retrieved July, 10, 2008 from http://www.cbc.ca/consumers/market/archive/files/health/redbull/
Cohen, H. (2008. April 2) Kids + energy drinks = dangerous mix. Seattle Times. Retrieved June 5, 2008, from http://seattletimes.nwsource.com/html/health/2004322357_zhea02energy .
Desbrow, B. & Leveritt, M. (2006) Awareness and use of caffeine by athletes competing at the 2005 Ironman Triathlon World Championships. International Journal of Sport Nutrition & Exercise Metabolism. 17(4), 545-558.
Dunlap, L. (2008) Wake up to the Facts: Energy Drinks & Alcohol Don’t Mix. The Journal of the Air Mobility Command’s Magazine. 17(2), 20-21.
Energy drinks’ buzz may pose some risk (2008, January 30) McClatchy – Tribune Business News. Retrieved June 5, 2008 from http://proquest.umi/compqdweb?did=1420710411&sid=1&Fmt=3&clientld=32919&RQT=309-&VName=PQD.
Fornicola, F. (2007) Energy Drinks: What’s All the “Buzz” About? Coach & Athletic Director 76(10), 38.
Griffith, D. (2008, May 11) Energy drinks make caffeine the drug of choice among California youth. Sacramento Bee. Retrieved June 5, 2008, from http://search.ebscohost.com/login.aspx?direct=true&db=nfh&AN=2W62W6639513775&site=ehost-live .
Add Grossman, S.J., Wechsler, H., Davenport, A.E., & Dowdall, G.W. (1997) Binge drinking, tobacco, and illicit drug use and involvement in college athletics: a survey of students at 140 American colleges. Journal of American College Health. 45(5) 195-200.
Janzen, J. (2008). CAFFEINE – Performance Enhancement or Hindrance? Sport Medicine Council of Manitoba. Retrieved June 30, 2008 from http://www.sportmed.mb.ca/uploads/pdfs/Caffeine%20good%20and%20bad.pdf
Lidz, F. (2003) The fuel of extremists (or, Taurine in your tank). Sports Illustrated 99(4), 8-16.
Lofshult, D. (2008) energy drinks may present danger. Idea Fitness Journal 5(4), 58.
Malinauskas, B. M.,Aeby, V. G., Overton, R. F., Carpenter-Aeby, T. & Barber-Heidal, K. (2007) A survey of energy drink consumption patterns among college students. Nutrition Journal. 6(35), 35.
Miller, K. E. (2008) Wired: Energy Drinks, Jock Identity, Masculine Norms, and Risk Taking. Journal of American College Health. 56(5), 481-490.
O’Brien, M. C., McCoy, T. P., Rhodes, S. C., Wagoner, A. & Wolfson, M. (2008) Caffeinated Cocktails: Energy Drink Consumption, High-risk Drinking, and Alcohol-related Consequences among College Students. Academic Emergency Medicine. 15(5), 453.
Red Bull Energy Drink (2008). FAQ. Retrieved July 10, 2008 from http://www.redbull.com/#page=ProductPage.FAQS
Red Bull, “It’s Not A Drink, It’s a Lifestyle” (2008). Retrieved July 10, 2008 from http://www.slideshare.net/yellowpod/326475-red-bull-its-not-a-drink-its-a-lifestyle/
Red Bull: The Other Energy Drink and its Effect on Performance. (2007) Athletic Therapy Today, 12(2), 43-44.
Retelny, V. S., (2007) Energy Drinks. Obesity Management. 3(3), 139.
Safe Use of Energy Drinks (2006). Health Canada. Retrieved June 20, 2008 from http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/prod/energy-energie-eng.php.
Umaña-Alvarado, M. & Moncada-Jiménez, J. (2005) Consumption of an ‘Energy Drink’ does not Improve Aerobic Performance in Male Athletes. International Journal of Applied Sports Sciences. 17(2), 26.