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Science & Research

Study uses small payments to incentivize undergrads to exercise

Participants earned up to $5 a week for exercise, motivation dwindled as study progressed

Staff Writer
Thursday, November 5, 2015

A group of researchers in the School of Public Health conducted a pilot study that examined whether small payments motivate undergraduates to exercise. An article detailing their findings was published in the November issue of the American Journal of Health Behavior.

Twenty-two undergraduates participated in the study, with the subjects separated into two groups: a control group that did not receive monetary incentives and an experimental group that did, according to the article. Participants in the experimental group could earn one cent for every four calories burned through exercise, up to a maximum of five dollars per week, according to the article.

When the researchers looked at past studies that used incentives to change behavior, they “saw there were major gaps in the literature, which was that there was not a lot of research on (incentives and motivation), and variables were really different from study to study,” said Kelley Strohacker, assistant professor of exercise physiology at the University of Tennessee at Knoxville and lead author of the study. The research was conducted while Strohacker was a postdoctoral researcher at the University between fall 2011 and fall 2013.

After Strohacker and her coauthors read multiple articles about studies that were conducted using large cash payments or giftcards, they aimed to test the effectiveness of small payments, Strohacker said.

Large cash payments demand a bigger budget for the study and may not be feasible to continue in the long-term, said Omar Galárraga, assistant professor of health services, policy and practice and a coauthor of the article.

Jennifer Tidey, associate professor of psychiatry and human behavior, who was not involved in study, has used monetary incentives in her own research to help people quit smoking.

“The challenge in these studies is how to sustain them,” Tidey said. “We can’t keep giving people lots of money forever. The incentive needs to be large enough to be effective, but it may take a while for the habit to kick in.”

The idea of rewarding desirable behaviors has often been used in treatments for drug abuse, said Jessica Emerson GS, a coauthor of the article. Previous studies suggested that incentives also worked in motivating subjects to exercise, Emerson added.

The researchers decided to focus on undergraduates because small monetary incentives are likely to be more appealing to a population that is not yet working and because it is a convenient sample, Galárraga said.

Payment was determined by an objective measure — caloric expenditure — rather than user-reported data, such as the number of steps taken in a day, Strohacker said.

“That was one of the novel pieces of our study,” Strohacker said. “We wanted a clear picture of what they were actually doing.”

Though the study found that the experimental group expended more calories compared to the control group, more research is needed in order to come to a stronger and more definitive conclusion due to the small sample size used in the study, Strohacker said.

But a trend does exist in which external incentives tend to have a greater effect on people who are doing quantity-based tasks, such as burning a certain number of calories, opposed to quality-based tasks, said Michael Ford, associate professor of psychology at the University of Albany, who was not involved in the study.

Despite the initial high levels of exercise at the beginning of the study — especially in the experimental group — both groups exhibited a decline in activity as the study progressed and after the study concluded, according to the article. Researchers are not yet certain how to address this slow decline in exercise and maintain motivation to exercise, Strohacker said.

Increased exercise is a desired health outcome because a sedentary lifestyle can lead to a number of health conditions, such as cardiovascular disease, Galárraga said.

“Cardiovascular disease is the number one cause of morbidity and mortality in the developed world,” Galárraga said. “It is a public health issue, not just an individual issue because it is a cost to society when somebody develops cardiovascular disease or diabetes.”

The researchers remain interested in the idea of external incentives as a way to change a broad spectrum of behaviors.

“The incentives can be used to motivate behavior initially, and eventually the behaviors can become habitual,” Ford said. “It becomes more enjoyable over time, leads to a sense of competence or becomes a social activity that helps one develop relationships.”

A new study led by Galárraga and David Williams, associate professor of psychiatry and human behavior and behavioral and social sciences and a coauthor of the article, that will examine the impact of small monetary incentives on exercise using a larger and more varied sample size is in the planning stage, Galárraga said. The group of researchers is collaborating with the YMCA of Greater Providence to see if results are consistent with what was found in the study.

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