Natalie DeMartini
Postive and Negative Messages and the Efficacy of Sports Drinks on Performance
To what extent do our preconceived ideas and beliefs effect an outcome? According to Natalie DeMartini's research on the expectancy effects of sport drinks, one's preconceived belief may be enough to override placebo. Her experiment involved a number of clever methodological techniques designed to view a wide range of how a placebo interacts with belief.
Some placebos involve intentially deceiving an individual with a fake treatment. Typically, placebos are most used in the medical community, using double-blind experiments, to determine the effectiveness of a particular treatment. For example, researchers test a drug's active ingredients when comparing them to placebo pills which are made out of pure sugar or water. It's inclusion in research helps to determine if the active ingredient actually has an effect, rather than simply relying on a patient's subjective self-report. Often, the belief that a particular treatment has an effect will be enough for the patient to report alleviation of pain or other symptoms. The phrase, "double-blind experiment," merely indicates that neither the medical staff administering a drug, nor the patients that take it, are aware if the treatment contains an active ingredient, or if it's fake. All that's left to measure is the different effects in both groups of people to more clearly see if the active ingredient is more efficacious. In other cases, a placebo may be simply informing a subject that a particular effect will follow the administration of any given treatment. A "placebo effect" is when an individual subjectively reports that the treatment in question has had an effect that coincides with the deception. This is also someitmes referred to as a "self-fullfilling prophecy."
DeMartini was interested in seeing if the placebo effect occurs in the area of nutrition, namely, with sports drinks. When consuming these products, do they actually aid in our physical activity, or do we just think they do? How can one tell if sports drinks do what they are marketed to do? Can it simply be attributed to "mind over matter"? When trying to decide a subject from which to draw an hypothesis, DeMartini says she remembers when she was active in endurance sports, that she witnessed other athletes consume various types of nutrition products "almost dependently." "They feel that it's necessary to win," she continues, "even though they are supposed to be taken after calorie depletion, not before." She says that her hypothesis was born from wanting to see if a sports drink "actually has an effect beforehand, or if it precedes a self-fullfilling prophecy."
Demartini hypothesized that participants who are primed with a positive message about sports drinks—"This is a new sports drink and it helps to increase athletic performance."—would perform better in a physical activity after drinking a placebo sports drink than would those who are given a negative message—"Sports drinks have been shown to have no effect on physical performance."
She recruited 65 participants and randomly assigned them to one of three groups: positive, negative, and neutral. (The neutral group had no message given to them). She did not instruct the participants that they were in any particular type of group. Each subject ran one mile two different times. The second time occured 48 hours after the first and was subtracted from the first run time to calculate a difference score. She also gave instruction to consume a sports drink moments before the second run, saying that it is a brand new energy beverage and accompanied that with the priming message. Every drink given to all participants was simply a mixture of water and flavoring.
According to the placebo effect principle, one would expect the positive message group to perform better, right? It actually turned out the opposite at first. Demartini didn't find evidence for the placebo effect when she combined all participants together in her analysis.
However, DeMartini included one crucial step in her experiment. Each participant filled out a demographics form that included the following question: "Do you believe that sports drinks have an effect on your athletic performance?" The answers particpants gave helped to shape further analysis and reveal an interesting interaction between expectancy and placebo.
Particpants could answer by stating a positive belief—"Yes, they work great"—a negative belief—"No, I don't think they help at all"—or a neutral belief—"I don't know."
It generally didn't matter what message the positive- and negative-belief individuals were given, they still performed according to their expectations. The placebo effect was observed, however, in the group of individuals who took a neutral stance. The ones given a positive message had a reduction in run time, while those given a negative message had an increase. Those not given any message at all had a slight decrease in run time, also indicating a possible placebo effect.
When asked how she felt about the process of her experiment, DeMartini recalled mainly two feelings: exhaustion and elation. "I didn't expect as many challenges to occur; It took a lot of planning and brainstorming to eliminate confounding variables," she said. "But," she added, "because I prepared so well in 305 [Research Methods], the project went smoothly."
And finally, when asked what it was like in the end when she had the opportunity to present her project to her friends and peers, DeMartini smiled and noted, "It was very satisfying because I felt confident and proud of my project. I learned something new and was excited to share it." The satisfaction was easy to witness in her tone and words. And while laughing, she concluded, "I added to the world of science, and that's pretty awesome."
You can see Natalie's study in more detail by viewing her project poster here.
Article by Kyle Evan Madsen
