Understanding how childhood activity leads to adult activity and fitness

Adults who are physically inactive are at risk for many health problems including obesity, heart disease, high blood pressure, diabetes, cancer, and more. Regular physical activity reduces the risk for all these problems, helps protect against chronic disease, and improves sleep, mood, and memory.  

Collaborators on the new project include Jonas Rubenson, associate professor of kinesiology at Penn State; Stephen Piazza, professor of kinesiology at Penn State, Timothy Ryan, professor of anthropology at Penn State, and Natalie Holt, assistant professor of evolution, ecology, and organismal biology at University of California Riverside. The group’s prior research demonstrated that when an animal grows, its muscles and bones adapt to activity.

“If a young person doesn’t exercise, people might worry about whether that child is developing bad habits or attitudes about physical activity,” said Piazza. “But we are aware that habits and attitudes can change. If, however, childhood inactivity modifies the muscles and bones in a permanent way that makes exercise more difficult for adults, then childhood physical activity is not just about building good habits — it is about avoiding physical barriers that discourage adult exercise.” 

The new funding will help the research team explore the amount and timing of activity needed for children to become active adults. Through animal research, they will examine the amount of exercise needed for muscles and skeletons to acclimate to physical activity. Additionally, they will seek to determine the ages during growth when exercise is most important for developing into an active adult. Finally, they will study whether starting exercise as an adult can reverse changes to the body that occurred due to childhood inactivity.  

“Basically, we are interested in understanding how late is too late for adopting physical activity behaviors,” Piazza explained. “Is it important to begin exercising very early in childhood, or can one start exercising late in adolescence and still avoid ill effects?” 

The researchers are currently recruiting research staff and postdoctoral fellows who will help conduct the studies. Eventually, this research may aid in the development of interventions that improve activity-related health for people throughout their lives. 

“Physical inactivity is a primary contributor to disease and mortality that also imposes a massive burden in terms of health costs,” said Rubenson. “We hypothesize that physical activity during childhood promotes healthy development of musculoskeletal structure that reduces the effort associated with movement. In turn, this healthy development may predispose adults to physical activity throughout their lifetimes. If we can determine the accuracy of this model, then it could help build a healthier society.”