University of Iowa researchers are preparing to further analyze the links between exercise and memory benefits after publishing a study on March 9 that took 13 years to finalize. 

The study found a single session of exercise can quickly boost brain activity linked to memory. 

Michelle Voss, the lead author and a professor in the UI’s Department of Psychological and Brain Sciences, said the team used data from 14 patients at UI Health Care to track neural activity before and after exercise. 

Voss said patients showed a high burst of activity from the hippocampus, a deep region of the brain that is critical for forming new memories. 

Voss said the researchers did not make a direct connection between exercise and memory, but look to do so in a future study projected to take two to three years. The study found bursts of hippocampal ripples, brain activity that typically occurs during quiet wakefulness and sleep, after a session of exercise. 

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“Different parts of the brain all have pieces of memories,” Voss said. “But the ripples help bind them together and package them for us to more easily recall them.”

Voss said her study opens the possibility of using exercise as a preventive measure against conditions that impair memory, such as Alzheimer’s disease. 

“As people get older, they tend to have more memory problems, and we don’t have good pharmacological treatments for preventing Alzheimer’s disease,” she said. “So the best we can do is look for ways to slow the process of memory decline.”

Voss said the higher a patient’s heart rate, the more hippocampal ripples they had, leading her to speculate that exercise intensity could correlate with ripple intensity. Voss said this potential link would also be explored in the future study she is brainstorming, which directly tracks memory. 

Voss said the study is already exciting because it shows that people can take steps to potentially improve their memory without following a months-long training plan.

“There are ways that you can sprinkle in exercise through your day that might give you a boost in that day without having to wait for those benefits,” she said. “In terms of the acute benefits, exercise can possibly help keep memory fresh.”

Rachel Cole, a co-author of the study and a research associate in the University of Minnesota’s Department of Neurology, assisted in the study when she was a graduate student at the UI. 

“Without this kind of work, while we might understand them, we might not be able to really explain the changes that humans can see from exercise,” she said. “I think this kind of direct measure of brain activity is priceless.”

Cole guided the UI Health Care patients through their exercise, keeping their stationary bikes stable and offering verbal encouragement.  

“At the time, I knew it was valuable data, but did not know exactly what would come of it,” she said. “It has been powerful to watch it come to fruition and see what kind of information can be gathered from this direct recording of human neural activity.”

Matthew Howard, UI Health Care neurosurgery chair, neurosurgeon, and a co-author of the study, said while other studies have confirmed the link between exercise and hippocampal ripples in animals such as mice and rats, this study marks the first such link in humans. 

“We have several projects kind of like this where Iowa is the first group in the world to do this particular type of study,” he said. “The reason is we have a strong collaborative relationship between scientists at different departments and our clinical neurosurgery group.”

Howard said while the study was crafted through the hard work of several researchers, the patients who volunteered for the exercise session should be shown gratitude as well. 

“These experiments help our scientific knowledge and help mankind. They might lay the groundwork for future treatments, but the experiments themselves don’t directly benefit the patient,” he said. 

Voss said the UI provided her with a unique intersection of all of the resources she needed for her study. 

“We’re lucky to be in Iowa,” she said. “There are only a handful of labs that can do this kind of work, bringing together direct recordings of neural activity in the human brain, with exercise research and memory research.”