6-Minute Bursts Of High-Intensity Exercise May Help Stave Off Conditions Like Alzheimer's: Study

A few minutes of high-intensity exercise per day may help stave off the onset of neurodegenerative disorders such as Alzheimer's and Parkinson's disease, a team of researchers has found. This is due to a protein that appears to be boosted by exercise.

For their study, published Wednesday in The Journal of Physiology, the researchers focused on the protein called brain-derived neurotrophic factor (BDNF). It is involved in learning, memory and neuroplasticity, they said, with the latter being the means by which the nervous system changes and adapts in response to stimuli.

Previous animal studies have shown that an increase in BDNF availability may have quite a few critical roles such as boosting cognitive performance and encouraging the storage of memories, according to The Physiological Society.

In a 2019 meta-analysis, for instance, the researchers found that serum BDNF levels were "significantly lower" in Alzheimer's Disease patients compared to healthy control subjects.

The authors of the current study said intermittent fasting and exercise have also been touted to have neuroprotective effects, adding that "an acute upregulation of BDNF appears to be a common mechanistic link."

"BDNF has shown great promise in animal models, but pharmaceutical interventions have thus far failed to safely harness the protective power of BDNF in humans," study lead author Travis Gibbons of the University of Otago said in The Physiological Society release. "We saw the need to explore non-pharmacological approaches that can preserve the brain's capacity which humans can use to naturally increase BDNF to help with healthy aging."

To shed further light on the matter, the researchers looked at the effects of different interventions on peripheral venous BDNF on 12 volunteer participants, half of whom were male while the other half were female. The interventions were a 20-hour fast, 90-minute light exercise, a six-minute burst of high-intensity exercise or a combination of fasting and exercise.

Of the three, it was the six-minute burst of high-intensity exercise (cycling) that was the "most efficient" way to increase BDNF, The Physiological Society noted. In fact, it increased four to five-fold more compared to prolonged low-intensity cycling.

Fasting, on the other hand, "had no effect on any metric of BDNF in peripheral circulation at rest," the researchers noted.

"Compared to 1 day of fasting with or without prolonged light exercise, high-intensity exercise is a much more efficient means to increase BDNF in circulation," the researchers wrote.

Although the mechanisms behind the differences are unclear, it's possible, they said, that the BDNF increase could be due to the increased number of platelets during exercise. Platelets can hold a lot of BDNF, and they're influenced more by exercise than by fasting.

For now, however, the researchers are still looking further into the matter.

"We are now studying how fasting for longer durations, for example up to three days, influences BDNF. We are curious whether exercising hard at the start of a fast accelerates the beneficial effects of fasting," Gibbons said. "We think fasting and exercise can be used in conjunction to optimize BDNF production in the human brain."