Muscle Fatigue Resistance via Energy Drink Consumption – Assessment of Pre- and Post- Experiment Participant Feedback

Robbins, Mary Kathleen (2015) Muscle Fatigue Resistance via Energy Drink Consumption – Assessment of Pre- and Post- Experiment Participant Feedback. Undergraduate thesis, under the direction of Carol Britson from Department of Biology, The University of Mississippi.


Download (387kB) | Preview


Energy drink consumption poses a health risk among college students, and long-term health implications are unclear. Because energy drinks are classified as dietary supplements, the FDA is not responsible for proving consumption is safe for the consumer. This research project studies the consumption of an energy drink and an energy bean’s effect on muscle fatigue using a grip force transducer, subjective perceptions of the participants after consumption across the two trials, and subjects’ opinion of energy drinks after the conclusion of the experiment. All subjects, ages 18-24 and regular users of caffeine, were recruited through email at the University of Mississippi to participate in this blind study where the investigator was aware of whether the subject consumes the caffeine-containing energy drink/bean or the placebo, but the subject was not. Grip strength (MVC), time-to-fatigue, heart rate, and pulse rate before and after consumption of the energy drink, or energy bean, were measured. Subjects consumed 8 ounces of an energy drink (containing 80 mg of caffeine or placebo) or 42.5 g of energy beans (containing 75 mg of caffeine or placebo). 10 minutes after consumption the subject was asked to squeeze a grip force for as long and hard as possible until fatigued. After measuring the physiological time-to-fatigue, grip strength, heart rate, and pulse rate, each subject completed a survey assessing his or her alertness and energy levels. One week later, subjects returned for participation in the second trial of the study. In the second trial, baseline measurement of grip strength (MVC) and heart rate were also measured. If the subject consumed the caffeinated energy drink or bean in the first trial, he or she consumed the placebo drink or bean in the second trial, and vice versa. The second part of the experiment measured the same values as the first part (physiological time-to-fatigue, grip strength, heart rate, and the subjective assessment). When all data were collected, subjects were provided with the post-experiment results, as well as information on the effects of energy drinks. After reviewing the results, subjects completed the free response exit survey. Significant physiological changes (MVC, time-to-fatigue, and heart rate) after consumption of the energy bean were not found. There was a significant decrease in maximum voluntary contraction after consumption of the energy drink, but no other significant physiological changes. Subjects who consumed the placebo and caffeinated version of the solid-form and the placebo version of the liquid-form did report a significant increase in mental focus. While previous studies have found physiological differences, such as increased heart rate, muscular strength, and time-to-fatigue from the ingestion of caffeine in energy drinks and energy beans, the present study did not find the same results.. This could have been due to subjects ingesting a too little dosage of caffeine, and variances in subjects activity levels, habitual dietary intake of caffeine, and the timing of the experiment. By increasing the amount of caffeine consumed, the subjective perceptions of mental focus, energy levels, and degree of fatigue may have clearer results. In the future, the mg of caffeine consumed should be increased or tailor-made to the subjects’ body weight to induce physiological results.

Item Type: Thesis (Undergraduate)
Creators: Robbins, Mary Kathleen
Student's Degree Program(s): B.A. in Dietetics and Nutrition
Thesis Advisor: Carol Britson
Thesis Advisor's Department: Department of Biology
Institution: The University of Mississippi
Subjects: Q Science > Q Science (General)
Q Science > QP Physiology
Depositing User: Mary Kathleen/MKR Robbins
Date Deposited: 05 Jan 2016 19:50
Last Modified: 05 Jan 2016 19:52

Actions (login required)

View Item View Item