UNIVERSITY PARK, Pa. — Research shows that one in four young adults do not meet United States government guidelines for aerobic physical activity. This lack of activity — combined with a high number of hours spent sitting — can increase the risk for cardiovascular disease later in life, according to Penn State researchers. A $3.6 million, five-year grant from the National Heart, Lung, and Blood Institute, will enable a team from the College of Health and Human Development and the College of Engineering to study how to increase young adults’ physical activity and decrease their weight gain through personalized messages that encourage people to move more and sit less.  

Previous research in the field has established that text messages can be used to promote physical activity. To build on that research, David Conroy, professor of kinesiology, human development and family studies, and public health sciences and affiliate in the Center for Healthy Aging, and Constantino Lagoa, professor of electrical engineering, are creating a personalized system that motivates people between the ages of 18 and 29 to move more, sit less and slow their future weight gain. Research has shown that, over time, young adults have been increasing their sedentary behavior and decreasing their physical activity, which could lead to increased cardiovascular health problems when they enter middle age.  

“Most people start out with ideal heart health,” Conroy said. “Unfortunately, that health erodes over time due to age, unhealthy behavior and other health complications. And once cardiovascular health is compromised, it is very difficult to restore. That is why it is so important to work to promote physical activity in young adulthood, before people develop serious cardiovascular risks like diabetes, hypertension or obesity.” 

Conroy studies how to motivate people to engage in healthy behavior. He said healthy young adults traditionally have been a difficult audience to reach for health interventions because they often do not have regular contact with physicians. Young adults, however, have been quick to adopt wearable technology like Fitbits and Apple Watches, making this technology an attractive intervention tool. This technology also enables researchers to respond to local conditions that can impact physical activity, like the weather.  

In this study, researchers will provide participants with a Fitbit smartwatch, an app for their smartphone and an internet-connected scale to automatically gather data without significant disruption to participants’ lives.  

Lagoa studies data-driven approaches to the design of controllers that ensure the behavior of a system satisfies specifications. In this project, researchers will develop personalized computer models for each participant based on which messages successfully motivated them to become physically active. Each model will incorporate information about the day of week, time of day, location-specific weather and the individual’s past response or non-response to different types of messages.  

“Different people respond differently to the same stimuli,” Lagoa said. “We know that messages can motivate activity, but some people respond to messages that encourage them to stop being sedentary, while others respond better to messages that encourage them to become active.”  

The researchers plan to recruit more than 300 research participants from across the U.S. starting in early 2023. Over 12 months, one third of the participants will receive text messages on a personalized schedule, one third will receive the same text messages on a random schedule and one third will receive no messages at all. This will allow the researchers to understand whether the messages are altering physical activity and whether their approach to personalization improves people’s responses to the messages.   

The internet-connected scales will report participants’ weight to the researchers at the start of the study, six months later, at the end of the 12-month study and six months after the study concludes.  

“Individual behavior changes over time,” Lagoa said. “Hence, individual behavioral models will be periodically updated to reflect these changes. Hopefully, the model-based controller will provide the best just-in-time ‘treatment’ for an individual’s current surroundings and state.” 

Conroy and Lagoa have collaborated for years, and they both expressed gratitude for Penn State’s unique support of interdisciplinary collaborations. The researchers emphasized that this project would not be possible without the application of engineering skills to the complex, real world problem of motivating health behavior in humans. 

“We want to help people establish healthy habits while they are young adults,” Conroy said. “We know that behavioral habits — good and bad — can last for decades. By intervening before people develop problems, we may be able to set young adults on the path to a long, healthy life.”