May 31 (UPI) -- A review of clinical trials suggests that at least 52 hours of any exercise, over the course of six months, can best maintain cognitive performance in healthy older adults and those with mild impairment and dementia.
Researchers at Beth Israel Deaconess Medical Center's Berenson-Allen Center for Noninvasive Brain Stimulation in Boston analyzed about 100 studies to find the optimal type and amount of exercise for older adults. Their findings were published Wednesday in Neurology: Clinical Practice.
The researchers found that just about any type of exercise can contribute to improved cognitive performance -- from aerobic exercises that include walking, running and cycling to weightlifting and mind-body exercises such as yoga and tai chi.
"While there is solid evidence to suggest that maintaining a regular exercise regimen can improve brain health we were most interested in how we could practically apply these scientific findings to the lives of our patients, their family members and even to ourselves," corresponding author Dr. Joyce Gomes-Osman, a post-doctoral research scholar at the Berenson-Allen Center, said in a press release. "For other forms of treatments such as prescription drugs, patients are prescribed a specific amount. Our study highlights the need to get this specific with exercise, too."
The most stable improvements in thinking abilities were found in mental processing speed in healthy older adults and individuals with mild cognitive impairment.
They found that weekly time spent exercising in minutes -- well-known to confer cardiovascular and other physical health benefits -- did not correlate with improved cognitive abilities. The researchers theorized people need more consistent exercise over a longer period of time for benefits in cognitive performance.
"It's very encouraging that the evidence supports all sorts of different exercise interventions, not just aerobic, to improve thinking abilities," said Dr. Alvaro Pascual-Leone, chief of the Division of Cognitive Neurology and the Director of the Berenson-Allen Center. "The most stable improvements in thinking abilities were found in processing speed, both in healthy older adults and individuals with mild cognitive impairment."
Researchers studied randomized controlled trials testing the impact of various exercise regimes on cognition. Initially they found 4,600 relevant studies, but focused on 98 that included more than 11,000 participants.
Researchers averaged and described the parameters, finding the relationships among exercise type, intensity, session duration, frequency and total hours, and five categories of cognitive abilities.
"We are still learning about all the ways in which exercise changes our brain, and we are also all different, so identifying an ideal exercise dose remains a challenge," Gomes-Osman said. "We have many more questions about exercise dose, and we will design further studies to follow up."