Authored by Monica O’Shea via The Epoch Times,

High-intensity interval exercise for just six months could be enough to improve cognitive function in older adults for up to five years, Australian scientists have found.

Researchers at the University of Queensland’s Brain Institute recruited a large group of healthy adults aged 65 to 85 for a six-month exercise program.

The volunteers undertook cognition testing as part of the study, along with high-resolution brain scans.

Five years later, researchers followed up with these older volunteers and found they had better cognition, even if they ceased exercising at the conclusion of the study.

Emeritus Professor Perry Bartlett said six months of high-intensity interval training is enough to “flick the switch.”

“If we can change the trajectory of ageing and keep people cognitively healthier for longer with a simple intervention like exercise, we can potentially save our community from the enormous personal, economic, and social costs associated with dementia,” he said.

The research, published in Aging and Disease, involved examining the results of three different types of exercise—low, medium, and high intensity.

The low-intensity exercise involved balance and stretching, while medium-intensity exercise involved brisk walking on a treadmill.

The high-intensity exercise, however, involved four cycles of running on a treadmill at near-maximum exertion.

The participants were randomly assigned to one of these three exercise interventions and attended 72 sessions during a six-month time frame.

Qualified exercise physiologists supervised all sessions to ensure personalised target heart rates were reached and maintained during the sessions.

In earlier pre-clinical work, the researchers discovered exercise can activate stem cells and boost the production of neurons in the hippocampus, where long-term memories are stored, thus improving cognition.

However, this study was the first of its kind to their knowledge that found “exercise can boost cognition in healthy older adults not just delay cognitive decline.”

High-Intensity Exercise Led to Cognitive Improvement

Queensland Brain Institute research fellow Daniel Blackmore explained that only high-intensity interval exercise resulted in a cognitive improvement that lasted five years.

“On high-resolution MRI scans of that group, we saw structural and connectivity changes in the hippocampus, the area responsible for learning and memory,” he said.

“We also found blood biomarkers that changed in correlation to improvements in cognition.”

Biomarkers can indicate how the body is responding to a disease or treatment.

Mr. Blackmore was optimistic about the findings, as they could inform exercise guidelines for older adults.

The researcher noted one in three people aged over 85 were likely to develop dementia, meaning the impact of the research is “far-reaching.”

Further research could look at varying types of exercise and how they can be incorporated into aged care, he explained.

“We are now looking at the genetic factors that may regulate a person’s response to exercise to see if we can establish who will and will not respond to this intervention,” he said.

“The use of biomarkers as a diagnostic tool for exercise also needs further research.”

The paper highlighted ageing dementia, including Alzheimer’s disease, could impact more than 130 million people around the world by 2050.

“Delaying the onset of dementia by five years would result in a decreased prevalence of 41 percent by 2050,” the paper stated.

“Therefore, it is critical to identify approaches that delay, slow, or even reverse age-associated cognitive decline. Modifiable lifestyle factors such as physical activity have been proposed to be effective at altering the trajectory of aging dementia.”

The study received support from the Stafford Fox Medical Research Foundation.

Exercise and Cognition Link ‘Weak’

Meanwhile, a separate review published in the Journal of the American Medical Association in February 2024 found physical activity was linked to better life cognition. But this association was “weak.”

However, even a weak association is important from a population health perspective, the authors noted.

“This systematic review and meta-analysis found that the association between physical activity and cognitive decline was very small, with no evident dose-response association,” the paper states.

“With that said, even weak associations can be clinically significant from a population health perspective when physical activity continues over decades.”

The authors said not very many “high quality” studies had been included in the review and suggested longer follow-up times.

“Further high-quality cohort studies with follow-ups longer than 10 to 20 years, fine-grain measures of physical activity and cognition at baseline, and high participation and follow-up rates are needed to solidify the evidence base in this area,” they stated.