Students conduct study on effects of energy drinks

Fort Worth, TX

9/9/2009

Lauren Sullivan, TCU Daily Skiff

Are energy drinks really that different from Coca-Cola? Melody Phillips, an assistant professor of kinesiology at TCU, and her team of six students, both graduate and undergraduate, are trying to find out through a research study that began in April. The study began with a senior research project.

"A student brought a paper to me, a research paper from a journal, that investigated the influence of Red Bull, a popular energy drink, on exercise performance and memory performance," Phillips said.

Phillips said the research looked as though it could be expanded upon, and it looked publishable. For the past several months, Phillips and her students have been collecting data on energy drinks and cycling.
The original question revolved around the benefits of the extra ingredients in energy drinks, Phillips said. The students involved in the research study wanted to know whether sugar and caffeine were the most active ingredients, or whether any of the other ingredients that are in energy drinks actually improved performance.

Phillips said energy drinks contain many other ingredients, such as taurine and glucuronolactone.

"In two different journal articles they did not control this really simple experimental design," Phillips said. "They didn't control for the caffeine and the sugar, which both have been shown to improve performance."

Phillips said it turned into a project that combined with her graduate-level exercise metabolism and endocrinology class.
Graduate student Jonathan Woodson was in Phillips' metabolism class and became involved in the project.

The study involved gathering data from various cyclists who were working under controlled conditions, Phillips said. The effects of energy drinks were compared to Coca-Cola and sparkling water. The research team primarily focused on the caffeine and sugar content.

Phillips said the Coca-Cola was set to match the levels of caffeine and sugar in the energy drink. The sparkling water contained no caffeine or sugar.

The cyclists involved in the study had to meet certain criteria, such as a certain level of fitness, Phillips said. Any cyclists who consumed no caffeine, or cyclists that consumed more caffeine than an equivalent of five cups of coffee per day were excluded from the study.

"They were trained cyclists, and there were a set of physiological criteria that they had to meet," Phillips said.

Cycling was the exercise form of choice because it had been used in similar studies, so it was easy to compare, and it also worked as a good control Phillips said.
Woodson said the participants ranged from 20 to 40 in age.

"We did a lot of our recruiting at some local races; we put fliers out," Woodson said.

Subjects received no money for their participation but were given tests that they would have had to pay for if not for the study. Among these tests were maximal oxygen consumption tests and body fat percentage tests.

The 12 participants came in to be studied four separate times, Woodson said. The first was introductory, but the next three were used to compare the different drinks.

Woodson said the subjects cycled for 25 miles each time. They had blood drawn to compare the results.

"They come in, usually about 7 in the morning, take some baseline measurements, give them their drink, and then they'd have to rest for about 30 minutes," Woodson said.

Woodson said after they rested, baseline blood samples were taken before they began their workout.

Phillips said there is still work to be done before the results can be published.

"All of the data has been collected, and we are now in the process of doing all the blood analysis," Phillips said, "Hopefully we'll get them all done this semester."

Media contact:
Shawn Kornegay
817-257-5061
s.kornegay@tcu.edu