A new study found six minutes of high intensity cycling was most effective at raising circulating levels of a brain protein associated with cognitive health. Depositphotos
It’s certainly not news to suggest exercise is crucial to healthy brain aging. A constant parade of studies over the past few years have flagged associations between exercise and cognitive health, from aerobic activity acutely improving problem-solving abilities to bi-weekly workouts lessening the effects of mild cognitive impairment.
But exactly how exercise helps the brain has been less clear. This new research focused on a specific protein dubbed BDNF (brain-derived neurotrophic factor), which is a crucial molecule involved in the growth, function and survival of brain cells. It has also been found to improve memory and slow the progression of neurodegenerative disease.
“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,” said lead author on the new research, Travis Gibbons. “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.”
The goal of the study was to understand how fasting and exercise influences BDNF production. To do this the researchers recruited a dozen healthy volunteers and tested their BDNF responses to four different interventions: fasting for 20 hours, low-intensity cycling for 90 minutes, high-intensity vigorous cycling for six minutes, or combined fasting and low-intensity exercise.
The findings revealed a short-burst of intense exercise dramatically increased levels of circulating BDNF compared to all the other tested interventions. But perhaps most interestingly, a short burst of high-intensity exercise was much more effective at boosting BDNF levels than a longer low-intensity session.
“Six minutes of high-intensity cycling intervals increased every metric of circulating BDNF by 4 to 5 times more than prolonged low-intensity cycling; the increase in plasma-derived BDNF was correlated with a 6-fold increase in circulating lactate irrespective of feeding or fasting,” the researchers reported in the study. “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.”
It’s important to note the study’s focus was very narrow. The researchers were only looking at how exercise and/or fasting affects plasma BDNF levels. So any subsequent interpretation in regards to dementia prevention or brain aging is still quite speculative.
Nevertheless, considering the body of pre-existing evidence showing exercise improves cognition and BDNF levels being associated with brain health, these findings do add new pieces to the puzzle of how to best maintain the aging brain. And according to Gibbons, further research is already underway looking at more ways exercise influences BDNF.
“We are now studying how fasting for longer durations, for example up to three days, influences BDNF,” said Gibbons. “We are curious whether exercising hard at the start of a fast accelerates the beneficial effects of fasting. Fasting and exercise are rarely studied together. We think fasting and exercise can be used in conjunction to optimize BDNF production in the human brain.”
The new study was published in the Journal of Physiology.
Source: The Physiological Society