A new study led by the University of Cincinnati found that weekly physical activity was associated with slightly slower declines in memory, thinking and movement among people with Parkinson’s disease. The findings point to possible benefits from remaining active as the disease progresses.

The research included 294 patients with mild or moderate Parkinson’s disease, whose average age was 66. Participants described their weekly physical activity through questionnaires and structured interviews about what they did at work, at home and during recreation.

Investigators counted both moderate and vigorous activity. Moderate examples listed in the study release included brisk walking, light swimming and doubles tennis, along with household tasks such as washing windows, vacuuming and mowing the lawn.

Vigorous pursuits included jogging, fast bicycling, team sports and singles tennis. Shoveling and carrying heavy loads also counted among the more demanding forms of activity considered by the researchers.

Researchers divided participants into three groups according to their weekly activity. The groups included those active for up to four hours, those active for four to eight hours and those reporting more than eight hours.

The research team monitored cognitive health for up to five years and motor function for up to seven years. This allowed investigators to examine how memory, thinking and movement changed among people reporting different amounts of activity.

Each additional hour of physical activity per week was associated with slightly slower declines in memory, thinking and movement over time. That association remained after researchers accounted for age, sex, education, weight and the severity of Parkinson’s disease.

Patients active for four to eight hours each week had slower declines in memory and thinking than those who exercised for less than four hours. Going beyond eight hours per week did not appear to deliver additional benefits for memory and thinking.

The potential benefits may depend not only on the amount of activity, but also on how long patients remain active and whether they continue exercising over time, according to study author Dong-Woo Ryu, M.D., Ph.D.

Ryu, of the University of Cincinnati and The Catholic University of Korea, described the challenges posed by the condition. "Parkinson’s disease is a brain disorder that causes movement and cognitive problems that gradually worsen, leading to disability and a loss of independence," he said in the press release.

"Previous research has shown associations between physical activity and movement symptoms. Our study found physical activity may have dual benefits, with associations with slower declines in movement and cognition," Ryu said.

"While our study found small differences between activity levels, these differences may become more meaningful over time," he said.

The researchers cautioned that most participants began the study with relatively strong memory and thinking skills. Additional research is therefore needed to confirm whether the findings apply more broadly among people with Parkinson’s disease.

The observational design also means the study could not establish that exercise directly slows the progression of Parkinson’s disease. It identified associations between activity and slower declines rather than proving that one caused the other.

Participants reported their own activity, creating the possibility that they did not accurately remember how much they exercised. The participants also came from a single location and were primarily White, which could limit how broadly the findings apply.

Dr. Vibhash Sharma, a neurologist at UT Southwestern in Dallas, Texas, was not involved in the research. He said exercise has established benefits for physical fitness and mobility, along with potential brain health benefits through mechanisms that are not fully understood.

Sharma noted that following patients for several years and assessing both cognitive and motor function were strengths of the research. He also said patients whose disease naturally progresses more slowly may be more likely to remain physically active.

Randomized studies will be needed to determine whether exercise directly slows cognitive or motor decline, the researchers said. The study was published Oct. 7 in Neurology, the official medical journal of the American Academy of Neurology.

The research received support from a grant provided by the Gardner Family Foundation and the Precision Medicine in Neurodegenerative Diseases Fund. Its findings further highlight regular physical activity as a potentially important part of managing Parkinson’s disease, while leaving key questions for future research.