“Historically, physical activity research has focused on how long someone exercises for or how many calories were burned,” said Patrick O’Connor, co-author of the study and a professor in the Mary Frances Early College of Education’s Department of Kinesiology. “The ‘dose’ of exercise has been the dominant way researchers have tried to understand how physical activity might influence mental health, while often ignoring whether those minutes were spent exercising with a friend or as part of a game.”

While research shows that leisure-time physical activity — like going for a run, taking a yoga class or biking for fun — correlates with better mental health outcomes, these benefits may vary significantly depending on the environment and circumstances surrounding the activity, according to the researchers.

To analyze these factors, the researchers reviewed three types of studies. These included large-scale epidemiological studies that examined health patterns in populations, randomized controlled trials where some groups received exercise treatments and others did not, and a much smaller but growing set of investigations into contextual factors.

Exercise and mental health

Multiple studies found that people who engage in regular leisure-time physical activity tend to report lower levels of depression and anxiety. But it’s less clear for other forms of activity like cleaning the house or working for a lawn care company. The context may matter as much as the intensity or amount of physical activity.

“For example, if a soccer player runs down the field and kicks the game-winning ball, their mental health is fantastic,” O’Connor said. “In contrast, if you do the exact same exercise but miss the goal and people are blaming you, you likely feel very differently. Anecdotes such as these show how context matters even when people are performing a similar exercise dose.”

Numerous randomized controlled trials also showed that adopting regular exercise routines boosted mental health, especially for individuals with existing mental health disorders. However, these studies were typically based on small, short-term and homogenous samples, so the results likely aren’t generalizable to larger, more diverse groups.

“The average effects on mental health are small across all the randomized controlled studies of exercise, and that’s partly because most of the studies focused on people who were not depressed or anxious — you do get bigger effects in those studies,” added O’Connor. “We’re communicating to scientists that larger- and longer-term controlled studies are needed to make a compelling case whether exercise does, or does not, truly impact mental health.”

Why context matters

Where the evidence is thinnest — but potentially most important — is in understanding contextual factors. The same physical activity can feel very different depending on who the activity was done with, as well as where, when and how.

Context can range from peer dynamics and instructor style to external conditions like weather or time of day. “If you’re outside and it’s hot, and you’re having to walk to work, that’s part of the context,” he added. “Or if you go and take a group exercise class — some instructors you really like, and some you don’t. So, that’s also part of the context.

“If we’re trying to help people’s mental health with exercise, then not only do we need to think about the dose and the mode, we also need to ask: What is the context?” O’Connor said.

For O’Connor, the takeaway is clear. It’s not just movement that matters. It’s the meaning, the setting and the experience surrounding the activity that determines the impact of exercise on mental health.

Co-authors of the study include Eduardo Bustamante of the University of Illinois Chicago; Angelique Brellenthin of Iowa State University; and David Brown, who recently retired from the Centers for Disease Control and Prevention.