The purpose of this study was to examine whether if there effects of energy drinks on cognitive performance or not. Popularity of energy drinks has increased significantly in recent years because of the talking of the ability of these drinks to increase both cognitive performance and physical energy. The energy drink Red Bull was tested to consider the validity of claims of the manufacturer about the ability of increasing cognitive performance. Giving the participants the stroop effect test was the way for testing cognitive performance. Participants’ task was to pronounce the color of ink on two sheets of words, the first sheet containing ordinary usage words and the second containing color names which were printed in an incongruent color. Participants then consumed a can of Red Bull energy drink and repeated the stroop effect test after 10 minutes. The results indicated that Red Bull energy drink didn’t keep down the interference and therefore did not improve cognitive performance. Red Bull Energy Drink has an improvement in reaction times of participants, which allowed them to finish the stroop test quicker than the rest of the participants who did not drink Red Bull.
Energy drinks can be defined as any drink with multi-energy enhancing ingredients such as vitamins and caffeine. Energy drinks are soft drinks that provide energy to improve physical activity of the user, as compared to a typical drink. Rather than providing food energy (as measured in calories), these drinks are designed to increase a user’s mental alertness, cognitive and physical performance by the addition of caffeine, vitamins, and herbal supplements which may interact to provide a stimulant effect over and above that obtained from caffeine alone.
The purpose of this study is to examine at the effect of energy drinks on human cognitive performance. The hypothesis is that energy drinks will have positive effect by improving person’s cognitive performance.
Review of literature
What are Energy Drinks?
Cathy Wong (2006) said that energy drinks are drinks that sold in cans or glass bottles which are typically found in stores, shops and bars. Most energy drinks contain large amounts of caffeine and sugar, in addition to other ingredients such as vitamin (b) and amino acids (taurine, for example), and herbs such as guarana.
People aged between 18 and 30 years are the target of these drinks which marketed to them as a catalyst and tonic under the meanings of terms such as power, speed and energy, such as Red Bull Energy Drink.
The effects of energy drinks:
According to Mr. Burgundy (2007) heart rate and blood pressure are the most important health risks related to the consumption of high doses of caffeine found in energy drinks. Therefore, may accelerate the heart rate to the person who drinks such high doses of energy drinks, so it is best to avoid these drinks for people who suffer from heart disease.
George Dvorsky (2009) mentioned that ” Energy drinks, which are typically laden with caffeine, taurine, ginseng and guarana, can improve mental and cognitive performance as well as increase subjective alertness. I can certainly vouch for these effects; after one drink I almost immediately feel the drowsiness dissipate. My mood is given a bit of a lift and I can re-focus on the task at hand ”.
Heneman, et al (2007) stated that improving physical and mental performance by using energy drinks has limited evidence that proof this benefit of consumption these drinks. Regrettably, because of the limitation of literature views, it’s unknown that this improvement is due to the caffeine, other herbal ingredients, or because of mixing ingredients found in these energy drinks.
Seidl et al. (2000) have conducted a study on mental performance by participation 10 graduate students, 6 female and 4 male, ages between 20 and 28 were selected for the experiment. Half of the students were non-caffeine users and the second half were regular caffeine users. Every individual abstained from consuming caffeine for 24 hours before each test session. Then, participants had the choice of consuming 7 tablets contain of caffeine, taurine, and glucuronolactone found in a can of Red Bull or 7 placebo tablets. After one hour, the tests would start. The participants’ eyes were closed and they listened to chain of frequent and infrequent sounds. Participants were instructed to conduct a silent count for infrequent tones and to ignore the frequent tones then prepare a report about the counted tones at the end of each session.
Also another test has been carried to measure the ability of attention in situations of tension in addition to the mood and the situation of the individual.
Results of these experiments, which ended after the consumption of the tablet containing caffeine, taurine, and glucuronolactone, an improvement occurred in the reaction time compared with the placebo tablets. Added to that, the caffeine, taurine, and glucuronolactone group experienced rising attention in a stressful situation and the total concentration compared with the placebo group. About the mood, the caffeine, taurine, and glucuronolactone group experienced no decrease in mood, whereas the placebo tablet caused a decrease in mood. So, the experiment showed that the mixing of caffeine, taurine, and glucuronolactone found in a can of the energy drink Red Bull has positive effects on both mood and cognitive performance. (cited in Levy, 2009).
The issue of energy drinks is quite complicated. Different aspects of this issue should be dealt with: what is energy drinks, its effects, its relationship with the cognitive performance which are sometimes hard to observe. Therefore, the researcher decided to apply the experimental approach which would enhance and examine the understanding of the issue.
Sixteen students (11 males, 5 females) from MSA University were volunteered for the researcher experiment.
Two stroop test sheets were constructed on A4 white paper. The color condition contained 15 words consisting of six names of colors (red, green, black, blue, yellow, and orange) printed in clear font which is Arial and 30 for the size of font for better vision. The words were printed in the same font and size. The color names were randomly arranged. The first sheet containing words in common usage and the second sheet containing words were filled in using the same six colors and in a model so that the color of the ink was incongruent with the color name printed on the paper. Red Bull, a popular energy drink was also used by giving a can for those in the Red Bull energy drink condition.
Participants were randomly assigned to either the Red Bull energy drink condition or the no Red Bull condition by test group. Each test group consisted of 8 participants. Every test group was told to them that they would be required to complete a short exercise. Participants were instructed to define the color of each word in the list of words printed as quickly as they can. Participants were told that if they committed any mistake, the researcher will notified them about the mistake, and they should correct their mistake before going to the next word. Participants were told that the time would start after the researcher gives them the test sheet and said “Ready? Start”. Time would be stopped upon completion of the correction for each test sheet. Participants were randomly selected to finish the exercise in the order of word, color, color, word or color, word, word, color in order to balance for the order effect. Participants were then parted and performed the exercise alone. Upon finishing of this exercise, participants were brought together again. The group that was randomly assigned to the Red Bull condition then was given a can of Red Bull energy drink. Participants were instructed to drink Red Bull as soon as they can, but not in quick way that may affect them badly. Most of the participants did not face any problems in the consumption of this drink in less than a one minute. The No Red Bull condition was not given any beverage. After ten minutes, participants started to complete the first exercise again in the same way. After finishing of the exercise for the second time, the participants were thanked.
The experiment was conducted to test the effects of Red Bull Energy Drink on cognitive performance. Stroop effect test was the way for determining and measuring the cognitive performance. There was no significant interaction between the consumption of Red Bull and the stroop effect. This indicates that Red Bull did not have control on the interference and confusion created by stroop effect. There was a significant primary effect for the Stroop effect which interference time to the condition of color more than the word. There was also a significant main effect for Red Bull Energy Drink; Red bull caused an improvement in times in both the color and word conditions. This suggests that Red Bull Energy Drink causes greater improvements on Stroop Effect Tests, but does not reduce the interference caused by the color condition.
Energy drinks are always showed as drinks that help to increase physical energy as well as improve mental performance. In this study, Red Bull Energy Drink was expected to decrease the amount of interference that caused by the stroop effect. In stroop effect test, the color incongruence was used as it is the most evincive of the effects of interference. Contrary to expectations completely, the energy drink Red Bull did not reduce or have a clear effect on interference created by the stroop effect tests. However, the energy drink Red Bull significantly made the participants complete the stroop effect test faster than the participants who did not receive the energy drink which is likely due to the caffeine in the energy drink which increase current energy and also decrease the sleepy feeling. These results indicate that although the energy drink Red Bull did not increase cognitive performance of participants but played down the reaction times. In other words, participants who consumed Red Bull made them faster but did not make them smarter in stroop effect test.
It’s possible that the stroop effect test may haven’t been the best measure of cognitive performance. Generally, stroop effect test is short and scores can improved due to continuous practice. Future research should expand and focus on the functions of guidance to the cognitive performance.
Dvorsky, G. (2009). Improve your performance with energy drinks. Retrieved December 7, 2009, from
Heneman, et al. (2007). Health Effects of Energy Drinks. Some Facts about Energy Drinks. Retrieved December 9, 2009, from
Levy, J. (2009) Energy Drinks: Potential Performance-Enhancers or Publicity Hype. Cognitive Performance. Retrieved December 11, 2009, from
Mr. Burgundy. (2007). The Health Effects of Energy Drinks. Retrieved December 5, 2009, from
Wong, C. (2006). Energy drinks. Retrieved December 5, 2009, from