Reviewing data from dozens of studies on older adults, scientists found that those who exercised an average of at least 52 hours over about six months — and for about an hour during each session — showed improvements in their thinking skills. The research didn’t show a link between a weekly amount of exercise and better brain function.
“The data seem to suggest … you have to keep exercise up for a while before you start to see these changes actually impact your life in a positive manner,” said study author Joyce Gomes-Osman. She directs the University of Miami Miller School of Medicine’s Neuromotor Plasticity Laboratory.
Study participants experienced specific, significant changes in mental sharpness, Gomes-Osman said. These included improvements in processing speed, or the amount of time needed to complete a task; and executive function, or the ability to manage time, pay attention and achieve goals.
“This is also super-encouraging, because these are the first two things that people, as aging progresses, start to have problems with,” said Gomes-Osman, who’s also a postdoctoral research scholar at Berenson-Allen Center for Noninvasive Brain Stimulation at Beth Israel Deaconess Medical Center in Boston. “The study provides evidence that with exercise, you can actually turn back the clock of aging in your brain.”
Among all participants, 59 percent were categorized as healthy adults, while 26 percent had mild cognitive impairment, which can precede the development of Alzheimer’s disease. Another 15 percent had diagnosed dementia. A total of 58 percent of participants did not exercise regularly before being enrolled in a study.
Of those who exercised, aerobic exercise was the most common type, with walking the most common form. Some studies incorporated a combination of aerobic exercise along with strength or resistance training; a small number used mind-body exercises such as yoga or tai chi.