The Influence of Red Bull on Exercise Heart Rate, Lab Report Example

Research Question

Does drinking Red Bull immediately before exercise influence the heart rate of healthy teenagers? To determine whether drinking Red Bull before exercise influences heart rate, the difference maximum heart rate (HR_max) will be determined by examining high school students who drink water before exercise and those who drink Redbull before exercising.

Background Information

A current media sensation indicates that drinking Red Bull contributes to an increased risk of heart disease (Macrae, 2008). However, there are no peer reviewed journals that attempt to validate this belief. Red Bull is formulated with many natural ingredients that contribute to energy storage such as glucose and sucrose. The concentration of these two components surpass levels that one would typically expect, at 5,250 and 8,600 mg, respectively. Furthermore, these high sugar concentrations are complemented with caffeine, taurine, and several forms of vitamin B, which are expected to supplement these effects. Since all of these chemicals work to produce energy, the physiological responses that are produced to intake include palpitations, tremors, gastrointestinal upset, chest pain, dizziness, insomnia, respiratory distress, and headache (Caffeine Informer, 2014).

Many teenagers consume energy drinks like Red Bull to assist their ability to stay awake in class and while studying. Furthermore, high school athletes use the drink to boast their energy and performance before games. Since this product is consumed frequently by active members of this age group, it would be helpful to determine whether there are any adverse health effects associated with its use. Although many side effects related to energy drink use have been reported, teenagers typically don’t report notice of these symptoms, which may be due to their age-related health status. Teenagers are typically in better physical and mental shape than their adult peers and are less likely to be affected by minor ailments. Therefore, there is a need to detect their reaction to energy drink consumption using variables that are not readily observable.

A useful way to determine whether Red Bull consumption has an impact on heart health of teenagers would be to measure their heart rate before and after consumption of the drink. Healthcare professionals typically rely on two measurements to determine heart rate of their patients. The first is known as basal heart rate (HR_rest), which measures an individual’s heart rate when they are at rest but not sleeping. The second is known as maximum heart rate (HR_max), which is the highest heart rate than an individual can achieve without causing themselves cardiac stress. HR_rest and HR_max can be measured using a heart rate monitor. However, HR_max is occasionally measured using a cardiac stress test in which the subject is asked to exercise while wearing an ECG that detects heart patterns (Froelicher et al., 2006).

Hypothesis

If the HR_max of individuals who consume Red Bull for exercise is greater than those who consume water before exercise, the hypothesis that Red Bull increases HR_max will be proven. It is expected that Red Bull will act as a stimulant that increases HR_max past its normal capacity.

Variables

Independent Variable

The independent variable in this experiment is exposure to Red Bull.

Dependent Variable

The dependent variable in this experiment in the difference between the maximum heart rate and the basal heart rate (HR_max – HR_rest).

Control Variable (Constant)

The control variable in this experiment in exposure to water, which will act as a placebo, rather than Red Bull.

Control of Variables

The HR_rest of all participants will be measured after sitting down for 5 minutes in silence. All heart rate readings will be conducted using the same heart rate monitor. Participants will be asked to perform the same exercise for the same amount of time, and be required to consume either the water (placebo) or Red Bull provided in less than 5 minutes. Participants will be asked to wear sneakers and a comfortable running outfit during the physical component of the experiment. Timing aspects will be measured using the iPhone timer application.

Materials

• Timex Personal Trainer Heart Rate Monitor watch
• 25x 20 oz. Red Bull original formula
• 25x 20 oz. Poland Spring water bottles
• iPhone with timer application installed
• Chair

Method

Ten high school students were selected for study by random sampling from my high school. Participants were approached and asked if they would be willing to participate in my study and that they would get either free bottled water or cans of Red Bull in exchange for their participation. They were asked to attend the experiment wearing sneakers and comfortable clothing that would allow free range of movement. Using the random number generator function in Microsoft Excel, 5 participants were randomized into group 1, the control group, and 5 participants were randomized into group 2, the experimental group.

The experiment took place over a 5 day period. All participants were asked to sit still in a chair upon arrival to the test site and to avoid movement, talking, and cell phone use during this period. At the beginning of this phase, they were given the same Timex Personal Trainer Heart Rate Monitor watch to wear. All participants were asked to sit in a chair for at least 5 minutes. The HR_rest value reported on the heart rate monitor watch was then recorded in beats per minute (BPM). Control participants were then given a 20 oz. bottle of Poland Spring water and experimental participants were given a 20 oz. can of Red Bull. They were then asked to consume their respective drinks in less than 2 minutes; time was tracked using the iPhone timer application. Immediately after drink consumption, participants were asked to run in a circle for 3 minutes without stopping as vigorously as they could. At the end of this 3 minutes, heart rate was again recorded using the heart rate monitor watch (in BPM). To retrieve additional data points, this experiment was repeated every day for 5 days.

To protect participant personal information, their names will be removed from records and coded for the purpose of data analysis. To determine the association between heart rate and Red Bull, the HR_rest will first be subtracted from the HR_max of each participant in each trial and then the difference in heart rate will be averaged. Descriptive statistics will be measured to determine the central tendency of this data.The correlation of heart rate change and consumption of Red Bull will then be calculated using a Pearson correlation test. For the purpose of statistical testing, the spread of all data will be assumed normal. To confirm whether there is an association between Red Bull consumption and heart rate, a student’s t-test will be performed. For all statistical tests, a p-value of 0.05 or less will be considered statistically significant and all calculations will be performed using Microsoft Excel. Lastly, a percent change calculation will be performed to determine the extent of the increase or decrease in heart rate. A percent change of greater than 5% will be considered significant.

Data Collection and Processing

Raw Data

Table 1. HR_max and HR_rest for participants drinking water immediately before exercise.

Table 2. HR_max and HR_rest for participants drinking Red Bull immediately before exercise.

Processed Data

Table 3.  Average HR_max and HR_rest for participants drinking water immediately before exercise.

Table 4.  Average HR_max and HR_rest for participants drinking Red Bull immediately before exercise.

 Table 5. Difference in HR_max and HR_rest for participants drinking water immediately before exercise.

Table 6. Difference in HR_max and HR_rest for participants drinking Red Bull immediately before exercise.

Tables 3 through 6 are a brief summary of the raw data generated in tables 1 and 2. The difference between HRmax and HRrest will be used for this analysis. As seen in table 5, the average difference between HRmax and HRrest in the control group is 117.24 BPM. The standard deviation of this value is 3.77 BPM. The median difference is 117.6 BPM; since the average and the median are approximately equal, we can assume that this data set follows a normal distribution. Lastly, the range of these values is 6.8 BPM. As seen in table 6, the average difference between HRmax and HRrest in the experimental group is 128.64 BPM. The standard deviation of this value is 1.86 BMP. The median difference is 129.4 BPM; like the control group, we can assume that the experimental data set is normal. The range of these values is 129.4. The average difference in BPM between the control group and experimental group is 11.4 BPM.

To determine the difference between the experimental and control groups, a percent change in heart rate was calculated using the average difference in heart rate. It was found that there was a 9.73% increase in heart rate of individuals who consumed Red Bull before exercise compared to those who only drank water. According to the standards defined in the methods section, this value is significant. In addition, a t-test was performed to determine the association between Red Bull consumption and heart rate. The null hypothesis for this test is that there would be no difference in average heart rate between the study groups after exercise. The p-value retrieved from this analysis was 0.0006; since this is less than 0.05, this is significantly significant and the null hypothesis can be rejected.

To determine the correlation between Red Bull consumption and increased heart rate after exercise, Pearson’s correlation was performed. The results can be seen below in figure 1.

Figure 1. There is a positive relationship between red bull consumption and heart rate.

In this figure, participants 1 to 5 were given water before exercise and 6 to 10 were given Red Bull. It is clear that the participants were given Red Bull had a higher HR_max than those given water. The coefficient of determination is 0.51 and the Pearson’s correlation coefficient is 0.71. Thus, there is a strong positive correlation between the consumption of Red Bull and high heart rate.

Conclusion and Evaluation

Conclusion

The results of this study suggest that consumption of Red Bull before exercise will lead to an increase in heart rate that is above normal levels. The analysis found that there is a percent increase in heart rate of 9.73% between individuals who consume Red Bull before exercise and those who do not. Furthermore, the statistically significant value given by the t-test indicates that these two variables associated. Lastly, the Pearson’s correlation coefficient for the relationship 0.71, indicates that this relationship is strong. Therefore, it is recommended that teenagers do not consume Red Bull for exercise. The ideal resting heart rate for high school students range from 80 to 90 BPM while the target active heart rate for high school students range from 186 to 202 BPM. The average difference in heart rate for individuals who consume Red Bull before exercise is 128.64 BPM. Therefore, there is a significant difference between the medically accepted exercise target heart rate and the heart rate experienced after Red Bull consumption.

Evaluation

Random error was accounted for by repeating the experiment 5 times for each individual. While we cannot expect the heart rate monitor measurement to be completely accurate each time, the collection of several data points increases the likelihood that the average of the data is accurate. Although individuals who did not consume the energy drink before exercise were used as the control group, an alternative method that may increase accuracy of results is the use of individuals in the experimental group as their own controls. Instead of the study occurring for 5 days, it will take 5 days; on the first 5 days the participants will be given water before exercise while on the second 5 days the participants will be given Red Bull before exercise. Even though this is an ideal study design, it was avoided due to the unfeasible length of the trial.

Improvements

Several improvements can be made to the study. First of all, use of a larger sample size would ensure that the average difference in heart rate is closer to that of the overall population. Doing so would ensure that the results have external validity for the student population at my high school. Second, it would be useful to determine whether the heart patterns of the subjects were impacted by Red Bull consumption in any way. Therefore, future studies should consider the use of ECG monitoring in addition to measures of heart rate. Lastly, it would be helpful to consider other factors that impact an increase in heart weight. The study participants all have different biological characteristics, including gender, body weight, height, and diet. It would be interesting to determine whether these factors play a role in the relationship between Red Bull consumption and increased heart rate.

References

Caffeine Informer. (2014). Energy Drink Side Effects. Retrieved from http://www.caffeineinformer.com/energy-drink-side-effects

Froelicher V, Myers J. (2006). Exercise and the Heart (fifth ed.). Philadelphia: Elsevier.

Macrae F. (2008).  Red Bull gives you…. increased risk of heart disease, say scientists. Mail Online. Retrieved from http://www.dailymail.co.uk/health/article-1045195/Red-Bull-gives—increased-risk-heart-disease-say-scientists.html