Energy Drinks and Caffeine: Safety and Effectiveness

Written by | Posted under Nutrition | 6 years ago


Caffeine is a drug that is present in the beans, leaves, or fruit of over 60 plants.  It is also one of the main ingredients in the ECA stack. History of it’s use by humans dates back to 2737 B.C. in China, when Emperor Shen Nung is said to have enjoyed the fist cup of tea.  The Olmecs of the Gulf Coast of Mexico are said to have begun cultivating the cocoa tree by around 1000 B.C.  And the coffee bean was discovered around 900 A.D. by a shepherd in Ethiopia, after noticing that his animals became particularly energetic after eating the berries of a coffee plant.  Now, 1,100 years later, Americans consume an average of 400 million cups of coffee per day!

In recent years the energy drink market has become a multi-billion dollar industry, with more than 30% of American adolescents using these supplements regularly.  Energy drinks are the most popular supplement being used by young people and athletes today.  Red Bull began as an adaptation of a Thai energy drink, and was first released in Austria in 1987.  It was later released in the United States in 1997, and in it’s wake, many other energy drink brands emerged, such as AMP, Monster, Redline, and Rockstar.   People often question the safety and effectiveness of energy drinks and caffeine.  I will address these two issues, and provide evidence based on the latest research.  My goal is not to necessarily answer the questions, but to provide information to you, the consumer, so that you can make an educated decision.


The primary active ingredient in energy drinks is caffeine.  Caffeine is a mild stimulant with many physiological and psychological effects, such as: increased heart rate, increased metabolic rate, elevated mood, decreased fatigue and drowsiness, and increased alertness.  Some negative consequences of caffeine use (usually excessive) include insomnia, nervousness, headache, tachycardia (rapid heart rate), diarrhea, and anxiety. Recent studies have suggested that caffeine does not increase dehydration or impair thermoregulation, two widely held beliefs.  More research needs to be done to validate these results.  When combined with alcohol, caffeine can affect the heart, and people who are predisposed to cardiac conditions such as arrythmias may increase their risk of a devastating cardiac event.

Most people don’t know or don’t pay attention to the amount of caffeine in energy drinks.  Let’s put it into perspective.  Soda manufacturers are allowed to put up to 71 milligrams (mg) of caffeine into a 12-ounce serving.  An average 12-ounce can of Coca-Cola has approximately 34.5 mg of caffeine in it.  Depending on how drip coffee is prepared and on the size of the serving, you can bet on between 65 – 200 mg of caffeine per cup of joe.  Energy drinks generally fall into this range of 65-200 mg/serving, such as Red Bull with 80 mg caffeine per serving.  Rockstar and Monster also contain 80 mg caffeine/serving, but they contain 2 servings per can.  There are  energy drinks, such as Celsius and JavaFit Energy Extreme, that exceed 200 mg/serving.

If you are a coffee drinker this doesn’t sound like too much caffeine.  But there is much more to energy drinks than caffeine.  Red Bull contains 27 grams of sugar per serving (unless you buy sugar-free Red Bull of course).  Monster also contains 27 grams sugar/serving, but there are 2 servings in each can!  Rockstar contains 30 grams sugar/serving (x 2).  Sugar is a carbohydrate that adds empty calories to your diet and also poses potential problems for blood sugar regulation.

Aside from caffeine and sugar, there are many other ingredients in these energy drinks.  Some of these ingredients include taurine, guarana extract, green tea leaf extractevodiamine, and many others that have been heavily researched.  However, many ingredients being used in energy drinks have not undergone such extensive research, and therefore should be approached with caution.  Also, the effects of a particular ingredient, such as caffeine, in isolation may not be equivalent to it’s effects when added to other ingredients (it’s effects may be enhanced or dulled-down).  An example of this is the enhancement of caffeine’s effects in combination with ephedra (but we saw how that turned out).  More research needs to be done in the area of in ingredient interaction.

Lastly, and redundantly, caffeine is a drug.  Issues associated with this include issues of dependence, withdrawal, and tolerance.  These issues have been studied with regards to caffeine itself, but not directly with regard to energy drinks.  Symptoms of caffeine withdrawal include headache, tiredness/fatigue, sleepiness, and irritability.  Because caffeine is the primary ingredient in energy drinks, it is reasonable to assume that this can occur with habitual use of energy drinks as well.



The answer to this question depends upon further clarification.  Previous research in this area has focused on caffeine by itself, but recent research has studied many different energy drinks.  I will not differentiate between energy drink brands in this article.

With regards to athletic performance:

  • Energy drinks are effective in enhancing alertness (concentration and memory), focus, and reaction time to various stimuli.  They can decrease an athlete’s perception of effort.
  • Energy drinks are effective in increasing exercise endurance and improving the quality of a resistance training workout.  This means that the time to fatigue and the volume of activity performed is increased.  However, energy drinks are not effective at increasing power or strength, such as increasing your 1-repetition maximum (a common measure of strength).
  • Recent evidence suggests that caffeine may play a role in recovery from a workout and help decrease pain and soreness, but more research is needed to validate these results.
  • Recommendation for use: Check with a physician before using caffeine as an ergogenic aid, especially if you have any cardiac risk factors.  Caffeine enters the blood stream within 15-45 minutes and it’s effects last between 2.5 and 7.5 hours.  It is most beneficial to ingest the caffeine between 30 -60 minutes before a workout.  Dosages of caffeine should not exceed 6 mg/kg body weight (2.2 lbs) in those not sensitive to caffeine.  Ergogenic effects have been observed with dosages ranging from 2 to 6 mg/kg body weight.
  • Caffeine is a banned stimulant at urinary levels of 12 micrograms/milliliter and over for any athlete competing in National Collegiate Athletic Association or International Olympic Committee events.

With regards to weight loss:

  • Energy drinks have been shown to increase fat expenditure and enhance fat utilization.    Caffeine alone has been shown to be effective in enhancing lipolysis (breakdown of fat), fat oxidation (breakdown and use of fat for energy), and reducing glycogen breakdown.  Also, consumption of energy drinks has been shown to increase caloric expenditure during activities.  Other indicators of weight loss such as body mass, body fat, insulin sensitivity, and lipid profiles have been shown to decrease as a result of consuming energy drinks.
  • Recommendation for use: Check with a physician before using caffeine as a dietary supplement, especially if you have any cardiac risk factors.  Research has shown that consuming 2 mg of caffeine per kilogram of body weight (2.2 lbs) can increase your resting energy expenditure (the amount of calories you burn at rest).

*All evidence from the February issue of the National Strength and Conditioning Association’s Strength and Conditioning Journal


As a final word of warning, the Food and Drug Administration (FDA) does not regulate the supplement industry in the same way that they regulate conventional food and drug products.  Under the Dietary Supplement Health and Education Act of 1994, supplement manufacturers are responsible for ensuring the safety of their product.  Manufacturers are not even required to receive FDA approval before producing or selling a product.  They are simply required to label their products in a “truthful manner that is not misleading”.  The FDA is only responsible for taking action against an unsafe supplement after it reaches the market.  Because the FDA is not involved in safety regulations before dietary supplements reach the market there is the possibility that some of these supplements are unsafe.  There is also the possibility of the manufacturer fabricating the ingredients and potential benefits.  If you choose to use dietary supplements of any kind, it is important that you find a company with a good reputation that you can trust.  Proceed with caution! If you are just looking to lose a few pounds, it might be better for you to find other safer alternatives, such as incorporating food that burns fat into your diet.


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