Regular aerobic exercise improves blood flow to the brain, which should help keep older people sharper as they age, a new study has found.
At least half an hour of brisk walking or jogging four to five times a week promoted better blood flow in and out of the brain in a small group of older adults, said study co-author Rong Zhang . He directs the Cerebrovascular Laboratory at the Institute for Exercise and Environmental Medicine, a collaboration between UT Southwestern and Texas Health Presbyterian Hospital Dallas.
“The intensity was like you were rushing to a meeting where you were 10 minutes late,” Zhang said. “You walk quickly and you feel out of breath.”
The brain needs about 20% of the body’s total blood flow to maintain its function as an organ, he said.
But as people age, blood begins to flow less freely in and out of the brain, a condition called cerebrovascular impedance.
Less blood flow means the brain receives lower levels of oxygen and nutrients, Zhang said.
It also means that toxins could build up in the brain because reduced blood flow is less able to flush out waste products generated by the brain’s high metabolism.
To see if regular exercise could help people maintain healthy blood flow to their brains, Zhang and his colleagues recruited 72 people between the ages of 60 and 80 to take part in a year-long experiment.
Half were randomly assigned to an aerobic exercise group, while the others were placed in a control group that performed stretching and toning activities.
The aerobics group started with three half-hour exercise sessions per week and gradually increased to four or five sessions lasting up to 40 minutes.
After a year of exercise, the researchers performed brain scans and arterial tests to see how much blood was flowing in and out of the participants’ brains.
The aerobics group showed significant improvement in cerebral blood flow by the end of the year, but the stretching and toning group did not.
This kind of improved blood flow should lead to better brain health, said Dr. Donn Dexter, a neurologist at the Mayo Clinic in Eau Claire, Wisconsin, and a fellow of the American Academy of Neurology.
“The data on improving cognition through exercise is pretty strong,” Dexter said. “I’ve never seen this approach taken before. It’s interesting that they look at exercise as a way to improve vascular health inside the brain. It adds more fuel to this hypothesis that the exercise improves brain health.”
Current guidelines recommend adults get at least 150 minutes a week of moderate-intensity exercise, Dexter and Zhang said.
“It’s hard to remember 150 minutes a week. Keeping track of that might be difficult,” Dexter said. “So what I tell them is to do 30 minutes a day, because 30 minutes a day will get you 150 minutes a week, even if you miss a day or two.”
This study shows that people can experience the benefits of exercise at any age, given that the participants were at least 60 years old, Zhang said.
“Exercise should be a lifelong habit. It’s never too late,” he said. “The research out there suggests that what’s good for your heart is good for your brain. That’s a message we need people to understand.”
At the same time, people shouldn’t feel pressured to do too much, Zhang added.
“I haven’t seen any evidence to suggest that if you go to extremes, like people training for a marathon, you’ll receive more benefit than the program we recommended,” he said. declared.
The clinical trial report was recently published in the Journal of Applied Physiology.
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