Exercise can help make you smarter. So can dancing, gardening, walking the dog, even housework!
Yaakov Stern didn’t exercise when he was younger. But after years of studying the effects of aging on the brain, the 65-year-old Columbia University researcher has learned a few things about how exercise can improve thinking skills. As a professor of neuropsychology, Stern knew of many studies showing how regular aerobic exercise boosts brain power. But his latest research yielded two significant new findings.
In the study, 132 subjects from 20 to 67 years old who were not exercising were split into two groups. One did aerobic exercise four times a week, cycling on a stationary bike or using an elliptical machine. The other group did just stretching and toning.
As in many previous studies, the exercising group improved their scores notably on tests that measured executive function, the ability to pay attention, organize and achieve goals. Also, an outer layer of their brains, called the left caudal middle frontal cortex, thickened, which is “usually taken to be a good sign” in relation to executive function, Stern said in an email.
That was no huge surprise. The more interesting thing was that improvements were seen across all age groups. And the effects were rather dramatic for the older individuals, when put into this context:
“The people who exercised were testing as if they were about 10 years younger at age 40 and about 20 years younger at age 60,” Stern said.
He and his colleagues detailed the findings in January in the online version of the journal Neurology.
The Best Medicine?
In addition to improving cognitive abilities?—?from executive function to memory?—?simply walking briskly 2.5 hours a week (figure 30 minutes each weekday) is known to improve blood pressure and cholesterol levels, increase energy and stamina, improve mood and mental well-being, and help you sleep better, according to the American Heart Association.
A growing body of research finds exercise is directly related to happiness, and likely is a cause. On the flip-side, exercise can help battle depression. A mere 10-minute walk can reduce stress and anxiety. And the evidence is conclusive that exercise improves overall physical health and lowers the risk of dying from several causes.
Here’s the thing: The effort required to see physical and mental benefits is not herculean, nor does it require Spandex and shoes with swooshes. In fact, the very word “exercise” may be a stop word for many sedentary individuals.
Physicians and other health experts, so quick to dole out pills and potions, should first think to prescribe “activity” to promote physical and mental well-being.
How Does it Work?
Exactly how physical activity offers so many brain benefits isn’t entirely clear. But scientists are zeroing in on some answers.
A brisk workout stimulates the release of chemicals that help keep brain cells healthy and grow new blood vessels in the brain, according to Harvard Medical School. Indirectly, exercise boosts mood, reduces stress and helps foster better sleep?—?all things known to improve brain power.
The benefits are actually visible inside your head.
“Engaging in a program of regular exercise of moderate intensity over six months or a year is associated with an increase in the volume of selected brain regions,” said Scott McGinnis, a neurologist at Brigham and Women’s Hospital and a neurology instructor at Harvard Medical School.
One meta-analysis of several studies looked into exercise’s effects on the hippocampus, a brain region involved in verbal memory and learning. The researchers found “aerobic exercise had significant positive effects on left hippocampal volume” compared to those who didn’t exercise. The exercise prevented a shrinking of the hippocampus that otherwise occurs, the scientists wrote in 2017 in the journal Neuroimage.
Physical activity also seems to have a protective effect on the brain in general.
One very interesting study monitored the activity levels of 454 older people who agreed to donate their brain tissue upon death. Through tests, the researchers found that those who were more active?—?even just doing routine tasks like housework?—?had better memory and thinking skills. Further, the brains of the less active individuals were later found to have more lesions that are linked to Alzheimer’s disease.
“Exercise is an inexpensive way to improve health, and our study shows it may have a protective effect on the brain,” said Aron Buchman of the Rush University Medical Center and lead author of the study, published in January 2019 in the journal Neurology. “But it is important to note that our study does not show cause and effect. It may also be possible that as people lose memory and thinking skills, they reduce their physical activity. More studies are needed to determine if moving more is truly beneficial to the brain.”
Indeed, more study is needed. But there’s little doubt left that some activity is better for the brain than none, and that more is even better.
Research published in 2017 in the journal Translational Psychiatry involved brain scans of 60 people, age 65 to 85, who hopped on exercise bikes three times a week for 12 weeks.
The key finding: The physical activity changed brain metabolism by preventing the buildup of choline, which in excess quantities is known to contribute to the loss of brain cells in dementia patients. Choline increased in the brains of a non-exercising control group.
“The elevation of choline could be a sign of neurodegenerative processes,” Silke Matura, one of the study leaders from Goethe University Frankfurt, said by email. “Thus, our finding of increased choline levels in the … control group but not in the training group could be interpreted as a neuroprotective effect of regular aerobic exercise by possibly slowing down neurodegeneration.”
Whether adults can even grow new brain cells, let alone whether physical activity plays any role, has been controversial for many years. But the debate seems to be in the process of settling on the side of “absolutely.”
Broad studies in 2018 and in 2019 found that older adults can, indeed, grow new brain cells. The headline from the 2019 study, published March 25: “Adult hippocampal neurogenesis is abundant in neurologically healthy subjects and drops sharply in patients with Alzheimer’s disease.”
And recent studies in rats and humans indicate exercise contributes to that neurogenesis.
Strong Body, Strong Mind
So if aerobic exercise can create new brain cells, improve memory and help us think more clearly, what about other forms of exercise? Weightlifting has also been found to be good for the brain, though fewer studies have been done, and intensity seems to be an important factor.
Research by Teresa Liu-Ambrose at the University of British Columbia compared the effects of cardio exercise and weight training on women who had early signs of dementia.
“We found that only participants who did weight training showed significant improvements in both memory and executive functions,” Liu-Ambrose said. “This is in contrast to earlier studies on healthy participants that showed cardio exercises to be beneficial. When we performed neuroimaging, we also observed areas of the brain responsible for memory and executive functions showing more neural activity after weight training.”
In one perhaps more grueling study, at least for the participants, 100 men and women age 55 to 86 who had mild cognitive impairment?—?a potential precursor to dementia?—?were put on a weightlifting program, twice week for six months. They worked with relatively heavy weights?—?80 percent of their max strength?—?and as they got stronger, the weights were increased.
Compared to control groups, these ever-more-fit seniors saw improved cognition that lasted even a year after the conclusion of the formal exercise program.
“The stronger people became, the greater the benefit for their brain,” said Yorgi Mavros, a University of Sydney researcher and lead author of the study, published in the Journal of American Geriatrics. “The key however is to make sure you are doing it frequently, at least twice a week, and at a high intensity so that you are maximizing your strength gains. This will give you the maximum benefit for your brain.”
Just About Any Activity is Good
The bottom line? Here’s a quote similar to those I ran across several times over from just about every researcher who has studied this field:
“I think that the evidence is overwhelming that one of the best things you can do for your physical and mental health is exercise,” said Stern, the Columbia professor.
I asked him whether this knowledge has coaxed him out of his chair.
“I have tried hard to increase my weekly exercise,” he said. “However, it is hard to change behavior. I think one trick is to build in some external motivation, like friends or a trainer who are waiting for you. Another is to figure out how to integrate exercise with your daily routine. For example, I go to the hospital cafeteria to buy lunch and then walk back up to my office.”
Skipping elevators and incorporating walks into your daily routine is great advice, and not just for brain health. Other research shows you don’t have to hit the gym for hours to see significant physical health benefits:
- Walking just an hour a week may improve longevity.
- Brief, intense exercise?—?even something simple like vigorously climbing three flights of stairs, three times a day?—?can improve fitness and make you feel better.
- Here’s a zinger: Firefighters who could do 40 push-ups in a row had a 96 percent lower risk of cardiovascular disease compared to those who couldn’t manage 10.
- A mere 13 minutes of weightlifting, thrice weekly, brings the same strength gains as sessions lasting three times as long.
Other research has found an array of things qualify as beneficial physical activity.
Dancing: Not only did dancing help stave off dementia and bulk up that important hippocampus volume, one study found, but it did a better job than a traditional endurance workout of cycling and walking at improving balance among a group of elderly people.
Gardening: A single 20-minute session of gardening?—?which included cleaning a plot, digging, raking, planting and watering?—?boosted levels of growth factors known to be good for the brain in a group of elderly South Koreans.
Anything? A study of 800 Swedish women, published in Neurology in February 2019, found those who had high levels of physical activity were 52 percent less likely to develop dementia over time compared to those who were inactive. Physical activity included things “such as walking, gardening, bowling or biking for a minimum of four hours per week, to regular intense exercise such as running or swimming several times a week or engaging in competitive sports.”
That’s not to suggest you should avoid vigorous exercise. Another study of 1,462 Swedish women across the years found those with high levels of fitness saw the onset of dementia delayed by 9.5 years, on average, compared to those with medium fitness.
None of the studies cited above are, on their own, conclusive. But taken as a whole, the conclusion is clear: It’s just not smart to be sedentary.
Writer: Robert Roy Britt: https://medium.com/luminate/almost-any-physical-activity-can-make-you-smarter-6e2f19960d31