The best exercise is one that fits an individual's lifestyle, says John Jakcic, associate professor in Pitt's Department of Health, Physical Education, and Recreation Education.

Prescriptions for a Healthy Life

Two Pitt faculty members are researching obesity from different perspectives

Deborah Aaron and John Jakicic—researchers in the University of Pittsburgh's Department of Health, Physical, and Recreation Education (HPRED) in the School of Education—both attack the obesity issue through their research, but they use different offenses.

Aaron, an assistant professor, is an exercise physiologist and epidemiologist whose research focuses on the epidemiology of physical activity in children and adolescents.

Jakicic, an associate professor and an exercise physiologist with practical work in behaviorism, studies weight-related issues from a clinical perspective. He emphasizes the importance of adopting and maintaining exercise.

Aaron relies on large-scale population studies to gather her data, noting that it is difficult to assess the physical activity of a group. She explained that more precise tools such as pedometers, activity monitors, and heart rate monitors are impractical to use in a population study. And questionnaires, more practical instruments, have an inherent bias because people are asked to recall what they have done in the past week, month, or year.

Aaron has been working on a longitudinal study, now in its fifth year, which examines physical activity during the transition from adolescence to young adulthood.

"We know that physical activity declines rapidly beginning in early adolescence," said Aaron. "Around ages 12 or 13, we start to see dramatic drop offs that appear to continue through late adolescence, and then there's a gap in the knowledge base."

In a past project, Aaron collected physical activity data on 1,245 adolescents, ages 12 to 14, who were in the seventh, eighth, or ninth grade at the start of the study. When the project ended in 1993, the participants were ages 16 through 18 and in the 10th, 11th, or 12th grade.

In a new study funded by the National Institute of Child Health and Human Development, Aaron is reconnecting with all 1,245 of those people, now in their late 20s, to bridge the knowledge gap about the physical activity of that age group. The two objectives of this study are to further document the changes in physical activity during either critical transition from adolescence to young adulthood, when there are many life transitions-college, jobs, marriage, children-and to determine how these changes affected physical activity and health.

"What we also wanted to do was examine if physical activity during childhood and adolescence has any influence on people's physical activity in adulthood," said Aaron. "The hypothesis reported in the literature is that if we get children to be active as children, then they will develop healthy lifestyles that will continue into adulthood. However, we don't have any data to support that."

Using the exact same data-collecting instrument to ensure validity, Aaron is continuing the work, along with colleagues Robert Robertson, a professor in HPRED; Ron LaPorte, a professor in the Department of Epidemiology; and Andrea Kriska, an associate professor in the Department of Epidemiology.

In addition to tracking physical activity, the researchers will track specific activities.

"If the hypothesis does hold true, that if we get kids to be active when they're young they'll continue to be active as adults, that's probably as a result of them identifying an activity that they enjoy and will pursue in adulthood," said Aaron.

Identifying an enjoyable activity is key to Jakicic's work, as well. In order to adopt and maintain exercise behaviors, individuals need to like the exercise they are doing, said Jakicic, director of the Physical Activity and Weight Management Research Center in Trees Hall.

Jakicic researches the role exercise plays in weight loss, but his work has shifted slightly, now also addressing the role physical activity plays in preventing weight gain.

There are public health guidelines on the amount of exercise required, but they are based on preventing cardiovascular disease, not controlling weight, said Jakicic, who is testing those guidelines.

"So they're saying, 'Exercising 30 minutes a day on most days of the week is important for health,' " said Jakicic. "People are interpreting that to mean that if they do that, they're not going to gain weight or they are going to lose weight, and there's no evidence that this is the case."

In fact, Jakicic said, there's some evidence that more time spent exercising is required if a person wants to lose weight or prevent weight gain. Although this may be discouraging news, it is important to understand, he said.

Jakicic, whose research is funded by the National Institutes of Health, works with fellow researchers Kara Gallagher, an exercise physiologist who is assistant director of the Physical Activity and Weight Management Research Center, and Amy Otto, an exercise physiologist and registered dietician at the center.

Another project in the works involves moderately overweight individuals who are at risk for weight gain. They will undergo an 18-month intervention trial that involves behavioral strategies to address the barriers that prevent them from exercising or following a weight-loss program.

Jakicic said he works with individuals to identify motivating factors that will lead to exercise. He also said he tries to simplify the message.

"The gym might be perfect for some folks, but it might not be the answer for everyone," said Jakicic. "People ask me all the time 'What's the best exercise?' It's the one that you enjoy the most and fits your lifestyle."

Both Jakicic and Aaron say it's all about education-getting the message into the schools and community recreational facilities.

"It's not about telling somebody what to do; it's helping somebody understand how to do it," said Jakicic. "It's being able to change somebody's life in a positive way." • PLW