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
High-intensity exercise improves memory in seniors
October 31, 2019
Science Daily/McMaster University
Researchers at McMaster University who examine the impact of exercise on the brain have found that high-intensity workouts improve memory in older adults.
The study, published in the journal Applied Physiology, Nutrition and Metabolism, has widespread implications for treating dementia, a catastrophic disease that affects approximately half a million Canadians and is expected to rise dramatically over the next decade.
Researchers suggest that intensity is critical. Seniors who exercised using short, bursts of activity saw an improvement of up to 30% in memory performance while participants who worked out moderately saw no improvement, on average.
"There is urgent need for interventions that reduce dementia risk in healthy older adults. Only recently have we begun to appreciate the role that lifestyle plays, and the greatest modifying risk factor of all is physical activity," says Jennifer Heisz, an associate professor in the Department of Kinesiology at McMaster University and lead author of the study.
"This work will help to inform the public on exercise prescriptions for brain health so they know exactly what types of exercises boost memory and keep dementia at bay," she says.
For the study, researchers recruited dozens of sedentary but otherwise healthy older adults between the ages of 60 and 88 who were monitored over a 12-week period and participated in three sessions per week. Some performed high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) while a separate control group engaged in stretching only.
The HIIT protocol included four sets of high-intensity exercise on a treadmill for four minutes, followed by a recovery period. The MICT protocol included one set of moderate-intensity aerobic exercise for nearly 50 minutes.
To capture exercise-related improvements in memory, researchers used a specific test that taps into the function of the newborn neurons generated by exercise which are more active than mature ones and are ideal for forming new connections and creating new memories.
They found older adults in the HIIT group had a substantial increase in high-interference memory compared to the MICT or control groups. This form of memory allows us to distinguish one car from another of the same make or model, for example.
Researchers also found that improvements in fitness levels directly correlated with improvement in memory performance.
"It's never too late to get the brain health benefits of being physically active, but if you are starting late and want to see results fast, our research suggests you may need to increase the intensity of your exercise," says Heisz.
She cautions that it is important to tailor exercise to current fitness levels, but adding intensity can be as simple as adding hills to a daily walk or increasing pace between street lamps.
"Exercise is a promising intervention for delaying the onset of dementia. However, guidelines for effective prevention do not exist. Our hope is this research will help form those guidelines."
https://www.sciencedaily.com/releases/2019/10/191031112522.htm