Aerobic exercise training linked to enhanced brain function
Regular aerobic exercise may decrease the likelihood of developing Alzheimer's disease
February 3, 2020
Science Daily/IOS Press
Individuals at risk for Alzheimer's disease (AD) because of family history or genetic predisposition who engaged in six months of aerobic exercise training improved their brain glucose metabolism and higher-order thinking abilities (e.g., planning and mental flexibility) called executive function; these improvements occurred in conjunction with increased cardiorespiratory fitness. The results of this study are published in a special issue of Brain Plasticity devoted to Exercise and Cognition.
Drugs currently available to treat AD have limited therapeutic capacity. At a time when both the human and monetary costs of the disease are projected to rise dramatically in the coming decades, there is a critical need to provide individuals with readily-deployable strategies that can decrease the likelihood of acquiring the disease or slow its progression. Researchers therefore investigated whether exercise training in asymptomatic individuals harboring risk for AD improves markers associated with AD.
"This study is a significant step toward developing an exercise prescription that protects the brain against AD, even among people who were previously sedentary," explained lead investigator Ozioma C. Okonkwo, PhD, of the Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health.
The study investigated 23 cognitively normal, relatively young older adults with a family history or genetic risk for AD. All patients had a sedentary lifestyle. They underwent a battery of assessments, including cardiorespiratory fitness testing, measurement of daily physical activity, brain glucose metabolism imaging (a measure of neuronal health), and cognitive function tests.
Half of the participants were randomly assigned to receive information about maintaining an active lifestyle but no further intervention. The other half participated in a moderate intensity treadmill training program with a personal trainer, three times per week for 26 weeks.
Compared to the participants maintaining their usual level of physical activity, individuals assigned to the active training program improved their cardiorespiratory fitness, spent less time sedentary after the training program ended, and performed better on cognitive tests of executive functioning (but not episodic memory). Executive function, an aspect of cognition that is known to decline with the progression of AD, comprises the mental processes enabling individuals to plan, focus attention, remember instructions, and juggle multiple tasks successfully. The participants' improved cardiorespiratory fitness was associated with increased brain glucose metabolism in the posterior cingulate cortex, an area of the brain linked to AD.
"This research shows that a lifestyle behavior -- regular aerobic exercise -- can potentially enhance brain and cognitive functions that are particularly sensitive to the disease. The findings are especially relevant to individuals who are at a higher risk due to family history or genetic predisposition," noted Dr. Okonkwo. The lead author on the study, Max Gaitán, MEd, of the Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, remarked that "an important next step would be to conduct a larger, more definitive, study. If these findings are replicated, they would have a tremendous impact on quality of later life, providing individuals with more years of independent living, active engagement with loved ones, and building memories."
https://www.sciencedaily.com/releases/2020/02/200203104450.htm
Exercise gives older men a better brain boost
Men have stronger positive correlation between fitness and brain function
February 13, 2019
Science Daily/American Physiological Society
New research suggests that the relationship between physical and brain fitness varies in older adults by virtue of their sex.
Cardiorespiratory fitness is the measure of how much -- and how well -- oxygen is delivered to the muscles during exercise. Fitness level has also been associated with changes in the brain's nerve-rich tissue, called gray matter, and better cognitive function in later life. Previous studies have also found cardiorespiratory fitness to be related to how the brain functions during periods of rest. Nerve connectivity in the brain during rest changes with age. These changes can negatively affect cognitive function. However, "the neural basis of sex differences in the relationship between fitness and brain function in older adults has not been directly explored," wrote researchers from York University and McGill University in Canada.
The research team studied one group of men and one of women, both with an average age of 67. The volunteers self-reported their typical daily physical activity level. The research team recorded the participants' height, weight, age, sex and resting heart rate to determine their cardiorespiratory fitness. They also administered imaging tests of the brain to record nerve function both within specific brain networks (local efficiency) and among all networks (global efficiency).
The men were found to have higher cardiorespiratory fitness levels than the women. However, the women had higher local network efficiency and lower global network efficiency than the men. This pattern of connectivity was more robust in the women and has been positively associated with executive function, which are skills that contribute to being able to focus, pay attention and manage time. Fitness levels, however, were more strongly associated with improving this brain efficiency pattern for men than women.
"Our findings that [cardiorespiratory fitness] is associated with brain function in a sex-dependent manner underscore the importance of considering sex as a factor when studying associations between exercise and brain health in older adulthood," the researchers wrote.
https://www.sciencedaily.com/releases/2019/02/190213124408.htm