Can 6 Minutes of Intense Cycling Put the Brakes on Alzheimer's?

January 12, 2023

Short bouts of intense exercise may help protect the brain from age-related cognitive decline by increasing production of a key protein involved in neuroplasticity, learning, and memory, new research suggests.

In a small study of healthy adults, 6 minutes of high-intensity cycling increased circulating levels of brain-derived neurotrophic factor (BDNF) to a significantly greater extent than prolonged light cycling or fasting.

However, the data do not suggest that 6 minutes of high-intensity exercise "wards off dementia," cautioned lead investigator Travis Gibbons, MSc, PhD candidate in environmental physiology at the University of Otago, New Zealand, and postdoctoral fellow at the University of British Columbia-Okanagan.

"Like all science, this is just a small piece that supports a potential mechanistic role for how exercise might improve brain health," Gibbons said.

The findings were published online January 11 in The Journal of Physiology.

Both intermittent fasting and exercise have previously been shown to have potent neuroprotective effects.

Six minutes of high-intensity exercise increased every metric of circulating BDNF four to five times more than prolonged low-intensity exercise.

Lactate Delivery?

"My leading theory is that during and following intense exercise, lactate produced by muscles is delivered and consumed by the brain," Gibbons noted.

"It takes high-intensity exercise to provoke this 'cerebral substrate switch' from glucose to lactate. Critically, this cerebral substrate switch has been shown to contribute to the early processes that upregulate BDNF production in the brain," he said.

However, "Whether this translates to 'warding off dementia' is not clear," Gibbons added.

J Physiol. Published online January 11, 2023.