Year-long exercise study reveals surprising impacts on mental health
We’ve seen studies offer some valuable insights into different ways exercise can be beneficial for brain health, from combating depression, to fighting dementia, to boosting our memory. New research has approached this topic with a long-term view, tapping into a year’s worth of Fitbit data to gauge the impacts of different types of physical activity, and turned up some interesting results.
The study is the handiwork of scientists at Dartmouth College, who set out to dig into the nuances of exercise’s effects on brain function and mental health. They sought to expand on studies in this area that had examined the effects of exercise over periods of days or weeks, by instead drawing on data from 113 Fitbit users across a 12-month period.
Across that year, those users were also made to answer questions about their mental health and perform different memory tests. The fitness data included daily step tallies, average heart rates and how much time spent exercising in different heart rate zones. The memory tasks, meanwhile, were designed to individually test the ability to remember autobiographical events, locations, and connections between concepts and other memories.
The results demonstrated how complicated the relationship between exercise and brain health is. While the researchers had expected to find a general positive trend between higher physical activity and memory and mental health, it wasn’t quite that simple. Low-intensity exercise brought improvements to specific memory tasks, while high-intensity exercise brought improvements specifically to others.
More surprisingly, those undertaking more high-intensity exercise reported higher stress levels. Those undertaking lower intensity exercise, meanwhile, reported lower rates of anxiety and depression.
"Mental health and memory are central to nearly everything we do in our everyday lives," says lead author Jeremy Manning. "Our study is trying to build a foundation for understanding how different intensities of physical exercise affect different aspects of mental and cognitive health."
Though it is early days for the research and the study was unable to reveal any causal effects, the scientists believe further work could lead to exciting new tools to manage cognitive health. Just as you might perform a particular workout in the gym to strengthen a particular muscle group, you might have a workout program tailored to keep anxiety at bay, or boost your learning and memory ahead of exam season.
"When it comes to physical activity, memory, and mental health, there's a really complicated dynamic at play that cannot be summarized in single sentences like ‘walking improves your memory,' or ‘stress hurts your memory,'" says Manning. "Instead, specific forms of physical activity and specific aspects of mental health seem to affect each aspect of memory differently."
The research was published in the journal Scientific Reports.