Exercise is good for the aging brain
Researchers find a single bout of exercise boosts cognition, memory performance in some older people
August 26, 2019
Science Daily/University of Iowa
Researchers have found that a single bout of exercise benefits some older people's brains. In experiments in which participants aged 60 to 80 exercised once and multiple times, the researchers found some individuals showed improved cognitive functions and working memory.
Exercise seems to endow a wealth of benefits, from the release of happiness-inducing hormones to higher physical fitness. New research shows it may provide a boost to the mind too.
University of Iowa researchers have found that a single bout of exercise improves cognitive functions and working memory in some older people. In experiments that included physical activity, brain scans, and working memory tests, the researchers also found that participants experienced the same cognitive benefits and improved memory from a single exercise session as they did from longer, regular exercise.
"One implication of this study is you could think of the benefits day by day," says Michelle Voss, assistant professor in the Department of Psychological and Brain Sciences and the study's corresponding author. "In terms of behavioral change and cognitive benefits from physical activity, you can say, 'I'm just going to be active today. I'll get a benefit.' So, you don't need to think of it like you're going to train for a marathon to get some sort of optimal peak of performance. You just could work at it day by day to gain those benefits."
Previous research has shown exercise can confer a mental boost. But the benefits vary: One person may improve cognitively and have improved memory, while another person may show little to no gain.
Limited research has been done on how a single bout of physical activity may affect cognition and working memory specifically in older populations, despite evidence that some brain functions slip as people age.
Voss wanted to tease out how a single session of exercise may affect older individuals. Her team enrolled 34 adults between 60 and 80 years of age who were healthy but not regularly active. Each participant rode a stationary bike on two separate occasions -- with light and then more strenuous resistance when pedaling -- for 20 minutes. Before and after each exercise session, each participant underwent a brain scan and completed a memory test.
In the brain scan, the researchers examined bursts of activity in regions known to be involved in the collection and sharing of memories. In the working memory tests, each participant used a computer screen to look at a set of eight young adult faces that rotated every three seconds -- flashcard style -- and had to decide when a face seen two "cards" previously matched the one they were currently viewing.
After a single exercise session, the researchers found in some individuals increased connectivity between the medial temporal (which surrounds the brain's memory center, the hippocampus) and the parietal cortex and prefrontal cortex, two regions involved in cognition and memory. Those same individuals also performed better on the memory tests. Other individuals showed little to no gain.
The boost in cognition and memory from a single exercise session lasted only a short while for those who showed gains, the researchers found.
"The benefits can be there a lot more quickly than people think," Voss says. "The hope is that a lot of people will then keep it up because those benefits to the brain are temporary. Understanding exactly how long the benefits last after a single session, and why some benefit more than others, are exciting directions for future research."
The participants also engaged in regular exercise, pedaling on a stationary bike for 50 minutes three times a week for three months. One group engaged in moderate-intensity pedaling, while another group had a mostly lighter workout in which the bike pedals moved for them.
Most individuals in the moderate and lighter-intensity groups showed mental benefits, judging by the brain scans and working memory tests given at the beginning and at the end of the three-month exercise period. But the brain gains were no greater than the improvements from when they had exercised a single time.
"The result that a single session of aerobic exercise mimics the effects of 12 weeks of training on performance has important implications both practically and theoretically," the authors write.
The researchers note their study had a small participant pool, with a homogenous population that excluded anyone with chronic health conditions or who were taking beta-blockers.
To address those limitations, Voss has expanded her participant pool in a current, five-year study to confirm the initial findings and learn more about how exercise alters older people's brains. The participants are healthy older individuals who are not physically active, similar to the participants' profile in the study's results reported here.
The National Institute on Aging, part of the National Institutes of Health, funded the research.
https://www.sciencedaily.com/releases/2019/08/190826110409.htm
Exercise activates memory neural networks in older adults
Study shows acute exercise has the ability to impact brain regions important to memory
April 25, 2019
Science Daily/University of Maryland
How quickly do we experience the benefits of exercise? A new University of Maryland study of healthy older adults shows that just one session of exercise increased activation in the brain circuits associated with memory -- including the hippocampus -- which shrinks with age and is the brain region attacked first in Alzheimer's disease.
"While it has been shown that regular exercise can increase the volume of the hippocampus, our study provides new information that acute exercise has the ability to impact this important brain region," said Dr. J. Carson Smith, an associate professor of kinesiology in the University of Maryland School of Public Health and the study's lead author.
The study is published in the Journal of the International Neuropsychological Society.
Dr. Smith's research team measured the brain activity (using fMRI) of healthy participants ages 55-85 who were asked to perform a memory task that involves identifying famous names and non famous ones. The action of remembering famous names activates a neural network related to semantic memory, which is known to deteriorate over time with memory loss.
This test was conducted 30 minutes after a session of moderately intense exercise (70% of max effort) on an exercise bike and on a separate day after a period of rest. Participants' brain activation while correctly remembering names was significantly greater in four brain cortical regions (including the middle frontal gyrus, inferior temporal gryus, middle temporal gyrus, and fusiform gyrus) after exercise compared to after rest. The increased activation of the hippocampus was also seen on both sides of the brain.
"Just like a muscle adapts to repeated use, single sessions of exercise may flex cognitive neural networks in ways that promote adaptations over time and lend to increased network integrity and function and allow more efficient access to memories," Dr. Smith explained.
https://www.sciencedaily.com/releases/2019/04/190425104310.htm
Exercise may improve thinking skills in people as young as 20
January 30, 2019
Science Daily/American Academy of Neurology
Regular aerobic exercise such as walking, cycling or climbing stairs may improve thinking skills not only in older people but in young people as well, according to a new study. The study also found that the positive effect of exercise on thinking skills may increase as people age.
The specific set of thinking skills that improved with exercise is called executive function. Executive function is a person's ability to regulate their own behavior, pay attention, organize and achieve goals.
"As people age, there can be a decline in thinking skills, however our study shows that getting regular exercise may help slow or even prevent such decline," said study author Yaakov Stern, PhD, of Columbia University in New York, and a member of the American Academy of Neurology. "We found that all participants who exercised not only showed improvements in executive function but also increased the thickness in an area of the outer layer of their brain."
The study involved 132 people between the ages of 20 and 67 who did not smoke or have dementia but who also did not exercise at the start of the study and were determined to have below average fitness levels. Participants were randomly assigned to six months of either aerobic exercise or stretching and toning four times a week. The two groups were equally balanced for age, sex, education as well as memory and thinking skills at the start of the study.
All participants either exercised or stretched and toned at a fitness center and checked in weekly with coaches monitoring their progress. They all wore heart rate monitors as well. Participants' thinking and memory skills were evaluated at the start of the study as well as at three months and at the end of the six-month study.
Participants in the exercise group chose from aerobic activities including walking on a treadmill, cycling on a stationary bike or using an elliptical machine. They ramped up their activity during the first month, then during the remainder of the six-month study they trained at 75 percent of their maximum heart rate. People in the stretching and toning group did exercises to promote flexibility and core strength.
Researchers measured participants' aerobic capacity using a cycling machine called an ergometer that estimates exercise intensity. Participants also had MRI brain scans at the start and end of the study.
Researchers found that aerobic exercise increased thinking skills. From the beginning of the study to the end, those who did aerobic exercise improved their overall scores on executive function tests by 0.50 points, which was a statistically significant difference from those who did stretching and toning, who improved by 0.25 points. At age 40, the improvement in thinking skills was 0.228 standard deviation units higher in those who exercised compared to those who did stretching and toning and at age 60, it was 0.596 standard deviation units higher.
"Since a difference of 0.5 standard deviations is equivalent to 20 years of age-related difference in performance on these tests, 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 added, "Since thinking skills at the start of the study were poorer for participants who were older, our findings suggest that aerobic exercise is more likely to improve age-related declines in thinking skills rather than improve performance in those without a decline."
Researchers also found an increase in the thickness of the outer layer of the brain in the left frontal area in all those who exercised, suggesting that aerobic exercise contributes to brain fitness at all ages.
"Our research confirms that exercise can be beneficial to adults of any age," said Stern.
Overall, researchers did not find a link between exercise and improved memory skills. However, those with the genetic marker for dementia, the APOE ?4 allele, showed less improvement in thinking skills.
A limitation of the study is the small number of participants. Larger studies over longer periods of time may allow researchers to see other effects in thinking and memory skills.
The study was supported by the National Institutes of Health.
https://www.sciencedaily.com/releases/2019/01/190130161638.htm
Regular aerobic exercise boosts memory area of brain in older women
April 8, 2014
Science Daily/BMJ-British Medical Journal
Regular aerobic exercise seems to boost the size of the area of the brain (hippocampus) involved in verbal memory and learning among women whose intellectual capacity has been affected by age, indicates a small study published online in the British Journal of Sports Medicine.
The hippocampus has become a focus of interest in dementia research because it is the area of the brain involved in verbal memory and learning, but it is very sensitive to the effects of aging and neurological damage.
The researchers tested the impact of different types of exercise on the hippocampal volume of 86 women who said they had mild memory problems, known as mild cognitive impairment -- and a common risk factor for dementia.
All the women were aged between 70 and 80 years old and were living independently at home.
Roughly equal numbers of them were assigned to either twice weekly hour long sessions of aerobic training (brisk walking); or resistance training, such as lunges, squats, and weights; or balance and muscle toning exercises, for a period of six months.
The size of their hippocampus was assessed at the start and the end of the six month period by means of an MRI scan, and their verbal memory and learning capacity was assessed before and afterward using a validated test (RAVLT).
Only 29 of the women had before and after MRI scans, but the results showed that the total volume of the hippocampus in the group who had completed the full six months of aerobic training was significantly larger than that of those who had lasted the course doing balance and muscle toning exercises.
No such difference in hippocampal volume was seen in those doing resistance training compared with the balance and muscle toning group.
However, despite an earlier finding in the same sample of women that aerobic exercise improved verbal memory, there was some evidence to suggest that an increase in hippocampal volume was associated with poorer verbal memory.
This suggests that the relationship between brain volume and cognitive performance is complex, and requires further research, say the authors.
But at the very least, aerobic exercise seems to be able to slow the shrinkage of the hippocampus and maintain the volume in a group of women who are at risk of developing dementia, they say.
And they recommend regular aerobic exercise to stave off mild cognitive decline, which is especially important, given the mounting evidence showing that regular exercise is good for cognitive function and overall brain health, and the rising toll of dementia.
Worldwide, one new case of dementia is diagnosed every four seconds, with the number of those afflicted set to rise to more than 115 million by 2050, they point out.
http://www.sciencedaily.com/releases/2014/04/140408213545.htm