Everyone needs a quick pick-me-up now and then, but are we becoming a nation of energy addicts? So it would seem, based on skyrocketing sales of caffeine-infused products. Today’s 24/7 culture, long work hours and poor sleep habits drain stamina and encourage us to guzzle liquid pep to combat daily sluggishness. Energy drinks, with edgy names and catchy slogans, have captured the youth market, igniting sales—and side effects (Seifert et al. 2011).

Energy beverages can invigorate consumers with a combination of sugar, caffeine and other ingredients, but they are also inviting increased public and medical scrutiny thanks to a plethora of reports linking their consumption to serious secondary effects and even deaths (Blankson et al. 2013). Energy drinks can cause significant health problems if consumed in large amounts or by certain populations.

Caffeine, the major ingredient, has been used for decades as a safe ergogenic aid, yet reports suggest it is causing many of these adverse effects. An avalanche of conflicting information has left many fitness professionals puzzling over how to advise clients on the risks and benefits of caffeinated energy boosters. This article highlights the latest information about energy drinks and their kin, providing strategies to support their safe consumption.

Jazzed on Drinks

Taisho Pharmaceuticals invented the first energy drink, Lipovitan D, a half-century ago (Meier 2013) to help night employees stay awake. Still available today, Lipovitan D counts taurine, B vitamins, nicotine and caffeine among its ingredients. In the 1980s, super-caffeine-infused Jolt® Cola became a hit on college campuses. Red Bull®, the king of today’s market, was introduced to the United States in 1997 (Meier 2013). Since then, hundreds of energy products, from beverages to candy, have flooded the market, promising increased focus and physical agility.

The alertness industry is big business, with energy drinks and shots netting $12.5 billion in 2012, a 60% jump from 2006 (Meier 2013; Packaged Facts 2013). Energy drink manufacturers see teens and college students as their biggest customers, with 30%–50% of this age group regularly consuming energy drinks to lift mental fog and boost athletic performance (Seifert et al. 2011). Shrewd marketing catapults the popularity of these drinks by enticing young males, in particular, with the assurance of gaining a competitive edge. Young consumers cite sleep deprivation, peer pressure, need for energy and sports performance as reasons for gulping energy brews (Taddeo, Harvey & Boutin 2012).

Safe or Scary?

The U.S. Food and Drug Administration is investigating unconfirmed reports of 13 deaths and various adverse events allegedly linked to energy products (FDA 2012a; FDA 2012b). While some drinks serve up moderate levels of caffeine and B vitamins in 8- to 24-ounce cans, there are also high-octane varieties called energy shots, which cram excessive doses of caffeine and B vitamins into 2-ounce servings and have been linked to numerous health complications (FDA 2012a).

Energy drinks have been associated with seizures, headaches, rapid heart rate, chest pains, irritability and anxiety (Iyadurai & Chung 2007). New-onset seizures are linked to heavy consumption (>24 ounces) on an empty stomach or if combined with another high-caffeine product (Iyadurai & Chung 2007). Deaths and other serious events occurred in children (Bronstein et al. 2011) and teens with pre-existing cardiac conditions (Meier 2012).

Combining energy drinks with alcohol is a hazardous college trend (Marc­zinski 2011). This duo can mask alcohol’s sedative effect, and each raises dopamine levels, stimulating the desire to drink both (Greenemeier 2010). College students with a history of consuming this volatile mixture are more likely to participate in or be the victim of risky behaviors (Howland & Rohsenow 2013).

But Don’t They Boost Performance?

Energy drinks are frequently used to increase athleticism. In a survey of U.S. college students (Hoyte, Albert & Heard 2013), 80% of those who said they participated in sports at various levels reported having used an energy drink within the past year to enhance athletic performance. Among sports players, 84% men and 74% of women said they consumed energy drinks. Semipro and intercollegiate players were more likely to use energy drinks than their intramural and club peers.

The International Society of Sports Nutrition’s (Campbell et al. 2013) position paper on energy drinks states that the ergogenic value of caffeine is well supported. Energy drinks can improve mental focus and anaerobic and/or endurance performance if consumed 10–60 minutes before exercise, the paper states, but it adds that many energy drinks contain additional ingredients whose benefits or other effects are not yet known. Low-calorie energy beverages may help with weight loss, but sugary energy drinks may incite weight gain and spike insulin levels (Campbell et al. 2013).

Athletes should consider the high sugar concentration when selecting an energy drink. Children and adolescents should use energy drinks only under parental supervision and be able to recognize the side effects. Indiscriminant use is not recommended. People with diabetes, cardiovascular disease or other metabolic or physical disorders should avoid energy drinks (Campbell et al. 2013).

What is it about energy drinks that produces negative health effects? Most point the finger at caffeine, but is this generally recognized as safe (GRAS) ingredient the culprit?

The Buzz on Caffeine

Caffeine is a central nervous system stimulant that is easily absorbed; blood values peak within an hour after ingestion. The half-life of caffeine is 5–12 hours, but alcohol will extend its stay in the body (Campbell et al. 2013). Most adult men and nonpregnant women can tolerate 500 milligrams a day (about four or five 8-ounce cups of coffee) without significant side effects (Sepkowitz 2013). Children may experience caffeine-induced irritability, anxiety, cardiac abnormalities and sleep issues with lower doses, so their caffeine intake should be <100 mg/day (Torpy & Livingston 2013; Health Canada 2011). Highly caffeinated energy drinks have no place in the diets of children or adolescents, according to the Committee on Nutrition and the Council on Sports Medicine and Fitness (2011).

Caffeine is frequently used as an ergogenic aid despite its diuretic effect. >> Consumed 45–60 minutes prior to anaerobic exercise, energy drinks containing about 2 mg of caffeine per kilogram of body mass may improve total lifting, but they have no effect on repeated high-sprint or agility performance (Davis & Green 2009; Campbell et al. 2013). However, performance may improve if caffeine is consumed 10–40 minutes before an aerobic activity such as cycling or running (Campbell et al. 2013). Sugar-free versions of energy drinks produced no improvement in high-intensity run time to exhaustion in young adults (Candow et al. 2009).

The FDA limits caffeine in soft drinks to 71 mg per 12 ounces, but it does not regulate caffeine in dietary supplements like energy drinks or products. Supplement manufacturers must list caffeine in the ingredients but do not need to list actual quantities (Rath 2012). Energy beverages contain different amounts of caffeine, and the quantities listed on labels are often inaccurate (Consumer Reports 2012; Blankson et al. 2013).

Many energy drinks contain guarana, a South American botanical packed with 40 mg of caffeine per gram. Caffeine from guarana is not typically included in the caffeine tally listed on energy drink labels (Blankson et al. 2013).

Caffeine-infused candy, chewing gum, marshmallows, Cracker Jack®, energy sheets that dissolve on the tongue and potato chips have inundated today’s market. Ingesting caffeine from multiple sources throughout the day can add up, triggering insomnia, irritability, rapid heartbeat and anxiety (Wolk, Ganetsky & Babu 2012).

´╗┐Tips for Taming Energy Drink Addiction


´╗┐´╗┐´╗┐For adults over 18 who have an appetite for energy drinks, here are some tips to avoid crashing:

  • Limit intake to 16 or fewer ounces and read label serving sizes.
  • Consume within the hour before playing a sport.
  • Limit total caffeine intake to <500 mg/day.
  • Drink water.
  • Avoid caffeine within 4-6 hours of bedtime.
  • Don’t combine with alcohol.
  • Don’t quit cold turkey. Gradually decrease daily intake.
  • If you have a health condition or take medications, talk to your doctor about how excessive caffeine might affect your health.
´╗┐All Those Ingredients Add Up

´╗┐´╗┐Trent is a 20-year-old college student and intercollegiate football player who works outs daily and wants that extra competitive edge. Trent tells his trainer he’s been experiencing headaches, insomnia, rapid heart rate, irritability, upset stomach and facial flushing. He wonders if energy drinks are causing his misery. The team trainer sends Trent to the dietitian, who asks him to complete a food record and to return the next day with a can of energy drink, all of his supplements and the completed food record.

Trent is drinking three 16-ounce cans of SuperXX energy drink daily. Each can contains 160 mg of caffeine and 200% of the Daily Value (DV) for niacin and B6, plus guarana, taurine, carnitine and 100 mg of ginseng. He takes two mega-multivitamins every day and uses a protein powder. His total niacin intake from supplements is 153 mg. Trent’s caffeine from energy drinks is 480 mg, but he buys a 16-ounce breakfast-blend coffee every morning; he doesn’t drink much water.

The dietitian surmises that Trent’s headaches, irritability and rapid heart rate are likely due to excessive caffeine intake from a combination of energy drinks and coffee. Guarana, ginseng and/or dehydration are probably contributing too. His excessive niacin intake is likely causing the facial flushing. High sugar content in the energy drinks and lack of water explain the stomach trouble.

The dietitian recommends an immediate appointment with the team doctor and suggests that Trent do the following:

  • Drink at least 8 glasses of water every day.
  • Take one multivitamin.
  • Find a protein powder with lower B vitamin levels.
  • Decrease his intake of energy drinks—gradually, to avoid caffeine withdrawal. The dietitian suggests decreasing consumption by one can a day every 2-3 days so that after a week, Trent is drinking just one can per day. Then he should switch to a smaller serving size.
  • Drink the energy drink within an hour before playing a sport and avoid consuming it close to bedtime.
  • Decrease morning coffee intake by buying a smaller size or by switching to a 16-ounce half-caf.

After 10 days, Trent reports that his headaches are gone, he’s sleeping better and his mood has improved. He still drinks one energy drink a day but does so within the hour before playing football. Trent sticks with water or a low-sugar sports drink most of the time.

It’s Not Just the Caffeine

Many are quick to blame caffeine for adverse reactions, but energy drinks are loaded with other ingredients that may trigger rapid heart rate, high blood pressure or heart palpitations when taken in excess (Higgins, Tuttle & Higgins 2010).

Guarana. The Brazilian cocoa seed contains guaranine, a caffeine equivalent that has not been evaluated by the FDA.

Sugar. Energy drinks contain 10%-12% sugar from glucose, sucrose or fructose. The combo of sugar and caffeine may boost athletic and cognitive performance, but this much sugar can cause gastrointestinal upset if consumed before sporting events. Diabetics should avoid high sugar concentrations (Campbell et al. 2013).

Taurine. A conditionally essential amino acid, taurine is abundant in food. Limited evidence suggests it may improve postexercise muscle repair (Higgins, Tuttle & Higgins 2010).

B6 and B12. B vitamins help with digestion and energy utilization. Energy drinks contain >100% of the Daily Value. One 5-hour Energy® shot contains >8,000% of the DV for B12 and 40 mg of B6 (>2,000% DV). Over 100 mg of B6 can trigger a rapid heart rate.

Niacin. Required for energy production, niacin may cause facial flushing and heart palpitations in adults consuming > 150 mg. Many energy drinks contain over 200% of the DV. Children drinking energy beverages will exceed their Recommended Dietary Allowance and may develop flushing and rapid heartbeat more quickly.

Ginseng. This herb is touted as a means of improving athletic performance, mood and immunity. Therapeutic doses, 100-200 mg per day, may cause insomnia, rapid heart rate and hypertension (Higgins, Tuttle & Higgins 2010).

L-carnitine. An amino acid that participates in fat metabolism, L-carnitine may stimulate recovery from exercise stress (Higgins, Tuttle & Higgins 2010).


It’s Not Kids’ Stuff

´╗┐Trendy energy products promise to propel consumers into a state of strength and vitality, but concerns are mounting as reports indicate an increase in emergency room visits by young people whose intake is high.

Most adults can safely enjoy an occasional energy brew, but children need to steer clear of these beverages. Fitness practitioners are in a unique position to educate clients on the potential side effects of caffeine-infused products and to instruct on their safe use as an effective ergogenic aid.


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Campbell, B., et al. 2013. International Society of Sports Nutrition position stand: Energy drinks. Journal of the International Society of Sports Nutrition, 10, 1.

Candow, D.G., et al. 2009. Effect of sugar-free Red Bull energy drink on high-intensity run time-to-exhaustion in young adults. Journal of Strength and Conditioning Research, 23 (4), 1271-75.

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FDA. Center for Food Safety and Applied Nutrition Adverse Event Reporting System. 2012b. Voluntary and mandatory reports on Red Bull Energy Drink. January 1, 2004-October 23, 2012.
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Martina Cartwright, PhD, RD

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