Understand how specific training intensities impact different aspects of mental and cognitive health

Understand how specific training intensities impact different aspects of mental and cognitive health

Exercise can improve your cognitive and mental health -; but not all forms and intensities of physical activity affect the brain equally. The effects of exercise are much more nuanced, with specific exercise intensities over a long period of time being linked to different aspects of memory and mental health, according to a new Dartmouth study. The results will be published in Scientific Reports and provide insight into how training could be optimized.

Mental health and memory are central to almost everything we do in our daily lives. Our study seeks to provide a basis for understanding how different intensities of physical activity affect different aspects of mental and cognitive health.”

Jeremy Manning, lead author, assistant professor of psychology and brain sciences, Dartmouth College

Researchers asked 113 Fitbit users to complete a series of memory tests, answer some questions about their mental health, and share their fitness data from the previous year. They expected that more active people would have better memory and mental health, but the results were more nuanced. People who tended to exercise at low intensity performed better on some memory tasks, while those who exercised at high intensity performed better on other memory tasks. Participants who exercised more intensely also reported higher levels of stress, while those who exercised regularly at lower intensity had lower levels of anxiety and depression.

Previous research has often focused on the effects of exercise on memory over a relatively short period of time, such as several days or weeks, but the Dartmouth researchers wanted to examine the effects over a much longer period of time. The data included daily step counts, average heart rates, how much time was spent exercising in various "heart rate zones" as defined by FitBit (resting, out of range, fat burning, cardio, or peak), and other information collected over a full calendar year. Study participants were recruited online from Amazon's Mechanical Turk, a crowdsourced workforce.

The four types of memory tasks used in the study were designed to examine different aspects of participants' abilities over different time periods. Two sets of tasks aimed to test “episodic” memory -; the same type of memory used to remember autobiographical events, like what you did yesterday. Another set of tasks was developed to test “spatial” memory -; the same type of memory used to remember locations, e.g. B. where you parked your car. The final set of tasks tested “associative” memory -; the ability to remember connections between concepts or other memories.

Participants who were more active in the past year tended to show better memory performance overall, but the specific areas of improvement depended on what types of activities people did. The researchers found that participants who frequently exercised at moderate intensity tended to perform better on the episodic memory tasks, while participants who frequently exercised at high intensity performed better on the spatial memory tasks. Sedentary participants who rarely exercised tended to perform worse on spatial memory tasks.

The researchers also identified links between participants' mental health and their memory performance. Participants with self-reported anxiety or depression tended to perform better on the spatial and associative memory tasks, while those with self-reported bipolar disorder tended to perform better on the episodic memory tasks. Participants who reported higher levels of stress tended to perform worse on associative memory tasks.

The team has made all of its data and code freely available on Github for anyone who wants to explore or better understand the dataset.

"When it comes to physical activity, memory and mental health, there are really complicated dynamics at play that can't be summed up in single sentences like 'walking improves your memory' or 'stress hurts your memory,'" says Manning. “Instead, certain forms of physical activity and certain aspects of mental health appear to influence each aspect of memory differently.”

With additional research, the team says their findings could have some exciting applications. "For example," says Manning, "specific exercise plans could be developed to help students prepare for a test or reduce their symptoms of depression to improve their cognitive performance and mental health."

Source:

Dartmouth College

Reference:

Manning, J.R., et al. (2022) Fitness tracking reveals task-specific links between memory, mental health and physical activity. Scientific reports. doi.org/10.1038/s41598-022-17781-0.

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