Substances that humans intake in food or drink contain various chemicals that affect the normal bodily functions of the consumer. Stimulants are drugs which when absorbed into the body raises physiological or nervous activity. The Red Bull Energy Drink is a stimulant, which contains psychoactive ingredients such as taurine, glucuronolactone and caffeine. Sportsmen and people requiring large amounts of energy or mental stimulation consume Red Bull because the beverage claims to “increase concentration and reaction speed”. Due to Red Bull’s claim, and its increasing popularity amongst teenagers in my grade, I wanted to test if the drink did actually affect the consumer psychoactively, and to how significant an extent.
To test the claim, I decided to assess 20 subjects in their psychomotor performance (reaction time/concentration) both at a normal bodily function state, and then under the influence of the chemical stimulant Red Bull.
Such a test would involve many variables that had to be kept constant. Hence, this test involved 20 male subjects aged 18 to 19 years of age, who were informed beforehand of the assessment procedure.
These subjects were given instructions to have at least 8 hours of sleep the night before the experiment, and were told to be present for the assessment on an empty stomach. These subjects were also not allowed to consume any other food or drink substances during the window period of testing, and the entire experiment was conducted on the same day in a 3 hour window (8:30am to 11:30am). Each subject was to consume 250ml of water (experiment control) and 250 of Red Bull.
Also, to allow the substances to absorb into the body of the consumer, reaction tests were conducted only 45 minutes after consumption of the substance. Such variables were important to have been kept in order to ensure that no other environmental factors or other chemicals being absorbed into the body will affect the experiment. The reaction speed assessment is conducted electronically. Each assessment consists of the subject concentrating on a yellow spot on the screen, which will turn red. Upon changing colour, the subject has to click using a provided mouse as fast as possible, and the reaction time is calculated electronically. Each assessment consists of 5 trials. A 2 sample t-test will be used to assess the if there is a significant difference between the reaction time of the subjects under the influence of water, versus under the influence of Red Bull.
Is there a significant difference between the reaction speed of 18-19 year old males under the influence of water and under the influence of Red Bull Energy Drink? Hypothesis I believe that the reaction speed of the subjects under the influence of Red Bull Energy Drink is shorter than under the influence of water. Considering how consumers drink Red Bull to boost themselves when feeling lethargic, or having difficulties focusing, Red Bull must have a significant effect on the body’s psychoactivity. I also believe that an increase in the chemical stimulants (taurine, glucuronolactone and caffine) as well as high sugar levels will cause an increase in psychoactivity within the consumer’s body due to the nature of the chemical stimulants.
(A sample sign-up form can be found on the following page.)
2. Measure 250ml of water and pour it into the large cup.
3. Repeat step 2 20 times. This is to prepare the initial control for the subjects to consume.
4. Give a cup to each subject. Subjects consume the 250ml of water at about 2 minute intervals from each other. Start the stopwatch once the first subject has begun drinking.
5. Prepare a computer terminal with the reaction test given in the following link below. Instructions on how to conduct the test are provided on-site. You may need a computer lab to carry out the test. Each test involves five trials. http://www.steriley.com/speed/
6. When 45 minutes has passed, allocate the first subject to the computer. Instruct him/her to carry out the test. Assist any volunteer who may require extra help.
7. When the subject has completed the test, collect the results into a table. Allocate the next subject to begin the test. This step should be completed in exactly 2 minutes.
8. Repeat steps 3-7 once more, but instead give each subject a can of Red Bull instead of water.
Investigate How Red Bull Energy Drink Affects The Reaction Time of 18-19 Year Old Human Males. (Sign-up sheet)
Venue: St Josephs Institution International
Date: 11 June 2011
Time: 8:30am – 11:30am (please be punctual)
Instructions (read carefully before signing up):
* Volunteers must be male and between the ages of 18 and 19.*
* Volunteers must receive 8 hours of sleep before the experiment day.
* Volunteers must not have consumed any food or drinks at least 3 hours before the experiment.
* Volunteers are not to consume any food or drink during the experiment period.
* Volunteers are not allowed to do any strenuous activities during the experiment period. This includes running, and other forms of exercise.
Std. Dev:| 0.033| 0.019|
Graph showing mean reaction times of 20 males, ages 18-19 under influence of water and of Red Bull:
From the graph, we can already infer that there is quite a large difference between the reaction times of the subjects under the influence of Red Bull as compared to water. The t-test to follow will show if this difference shown on the graph is a significant difference or not.
I will now use a t-test to prove whether there is a significant difference between the reaction times of an 18-19 year old male under the influence of water or Red bull. Null Hypothesis (H0): There is no significant difference between the reaction times of an 18-19 year old male under the influence of either water or Red Bull Energy Drink. Alternate Hypothesis (H1): There is a significant difference between the reaction times of an 18-19 year old male under the influence of Red Bull Energy Drink as compared to water.
For this experiment, the degrees of freedom is calculated to be: 20+20-2=38. The t-value as provided by the GDC is 6.2966 or 6.30 corrected to 3 significant figures. The p-value as provided by the table is 1.684 (at 40 d.f) with a confidence level of 95%. 6.30>1.684,
The value of t is larger than p.
The P-value as calculated by the GDC is 2.232737 x 10 -7 or 0.000000223 (3.s.f.) P<0.05
By conventional criteria, this difference is considered to be extremely statistically significant.
CONCLUSION AND EVALUATION
Because the P-value as provided by the GDC is less than 0.05, we reject the null hypothesis (H0) in favour of the alternate hypothesis (H1). Therefore, we can conclude at the end of this experiment, that there is a significant difference between the reaction times of an 18-19 year old male under the influence of Red Bull Energy Drink as compared to water. Red Bull, therefore, does “increase concentration and reaction speed” as it claimed. This proves my hypothesis to be correct, which shows that the chemical stimulants like taurine, glucuronolactone and caffeine found within Red Bull do indeed speed up the body’s psychoactive function significantly. Furthering my research, my hypothesis is further proved by another similar study on the effects of Red Bull. The test consisted of 80 subjects aged 20 years old, and they were provided questionaires testing different cognitive functions such as impulsiveness, attention, stimulation, sedation, mental fatigue and behavioural control. The results had shown that “Red Bull decreased reaction times on the behavioural control test. It also increased the subjects’ own ratings of how stimulated they felt and decreased their feelings of how mentally fatigued they felt.”
Although I have proven my hypothesis correct in this experiment, there are many areas that can be improved on in my method. I will be discussing them in this following section. Firstly, I feel that the results I have received from the experiment are precise and accurate. This is because no human error involved in taking measurements of the reaction time, and reaction time is calculated electronically precisely to 0.001s. Also, each reaction speed assessment involved 5 trials, which improved the reliability of the result. However, in the future to increase reliability of the results, more trials could be taken (such as 10 trials) per reaction speed assessment. Nevertheless, I the results reflect a strong trend that for all test subjects, their average reaction times between under the influence of Red Bull dropped as compared to under the influence of water. There were no anomalous results as such.
Secondly, I could improve on the method nonetheless by increasing the number of test subjects from 20 to a larger sample size, like 30. Perhaps also, the experiment could be widened further to involve female subjects as well. The reason why I did not choose to do so was because as Red Bull was high in sugar content, it was relatively difficult to find a large sample size of female volunteers, and also due to time constraint, I decided to limit the experiment to males, aged 18-19 only.
Thirdly, throughout the experiment, I ensured that my controlled variables were controlled strictly using the apparatus on the list. However, an improvement can be made to the controlled variable “Interval of time subjects are given between the consumption of fluid and reaction assessment”. I realized during the experiment that some subjects found difficulty in consuming the liquid all at one go, especially with Red Bull which was sickly sweet. Hence, some subjects finished sooner than others, and even though that amount of time (± approximately 2 minutes) can be considered negligible, it may affect the result. Also, perhaps I could increase the waiting interval of 45 minutes to 1 hour or slightly longer. That may allow the body more time to absorb the fluids and that could increase the reliability of the results attained.
Fourthly, some of the test subjects in the experiment found a slight difficulty in being able to react as quickly during the reaction speed assessment because they felt the coloured circle on the screen rather small. In the future, a better electronic reaction speed test could be used, one where changes can be detected with more ease. Also, some subjects felt distracted during the reaction speed assessment because of things happening outside the room, or sudden noises that cause a disturbance. In the future a more conducive location could be used for the test, perhaps quieter with lesser windows.
Lastly, after the experiment I began to consider if the drink Red Bull had a placebo effect to it. Perhaps the chemical stimulants really do affect the mind, but I wondered if subjects would have faster reaction speeds on Red Bull as compared to water if they were not told that they were consuming Red Bull. Perhaps because of Red Bull’s claim of being able to “increase concentration and reaction speed” that consumers are already psychologically influenced that their psychoactivity will be increased and hence become more alert and focused. In the future, perhaps a placebo fluid could be given to the subjects to test if their reaction speeds remain faster than when under the influence of water or not. However, such a placebo drink would be hard to make, as it has to taste similar to Red Bull in order for it to work.
[ 1 ]. C Alford, H Cox, R Wescott. The Effects of Red Bull Energy Drink on Human Performance and Mood. http://www.nootropics.com/red-bull/index.html
[ 2 ]. G Matthew, S Darren, S Jason, H Melanie, G Kimberly. Attention and Reaction Time in University Students Following the Consumption of Red Bull. http://www.gustrength.com/nutrition:redbull-and-reaction-time [ 3 ]. FYI Living. Red Bull May Decrease Reaction Time.