A Seven-Year Study Finds More Weekly Activity, Not Harder Workouts, Tied to Slower Parkinson's Decline

People with Parkinson's disease who reported more hours of physical activity each week had slower declines in movement and in thinking over as long as seven years, and the extra benefit did not come from making the workouts harder, a study published Wednesday in Neurology found.

The paper followed nearly 300 people with mild to moderate disease. It does not prove that exercise slows the illness. It shows an association. "Parkinson's disease is a brain disorder that causes movement and cognitive problems that gradually worsen leading to disability and a loss of independence," said study author Dong-Woo Ryu, a physician and researcher at the University of Cincinnati. "The possible benefits of physical activity for people with Parkinson's disease may depend on how long they stay active and whether they continue exercising over time. While our study found small differences between activity levels, these differences may become more meaningful over time."

Participants filled out questionnaires on hours spent active at work, at home and in hobbies. Moderate activity included brisk walking, doubles tennis, light swimming, vacuuming and mowing. Vigorous activity included jogging, fast cycling, team sports, singles tennis, shoveling and carrying heavy loads. Researchers then split the reports three ways: total time, a volume score that weighted vigorous work more heavily, and vigorous time alone.

The strongest link was with time. People who reported more than eight hours a week of moderate-to-vigorous activity had the slowest declines in memory and thinking and in motor scores. Those active at least four hours a week still declined more slowly than those under four hours. In extra analyses, vigorous activity added nothing once total time was accounted for. The answer the Washington Post framed as the old debate — harder, or longer — came out as longer.

The size of the difference was small in a single year and is the reason the authors urged caution. Adjusted for age, sex, disease duration, education, body mass index and stage at the start, each extra weekly hour was tied to 0.035 fewer points of annual decline on the Montreal Cognitive Assessment and 0.082 fewer points of annual worsening on the movement section of the MDS-UPDRS scale. The highest-activity group's motor slowing, against the group under four hours, reached statistical significance. "Taken together, these results suggest that physical activity may provide dual clinical benefits by independently reducing both motor progression and cognitive decline in PD," the researchers wrote.

Senior investigator Alberto Espay, a movement-disorders specialist and professor of neurology at Cincinnati, told Medscape the findings suggest activity "may influence the cognitive trajectory of Parkinson's disease, alongside its motor benefits." No drug has been shown to change the course of the disease. Two randomized trials have shown short-term motor gains from exercise. Long follow-up on both movement and cognition has been the gap this cohort was built to fill.

Ryu noted the limit that matters for a reader with a new diagnosis. Participants generally had good thinking and memory at the start, he said, "so our results should be interpreted with caution and further studies are needed." People who can still log eight hours a week are not the same people who cannot get out of a chair. The study cannot say whether the activity caused the slower course or whether people whose disease was already slower were the ones still able to stay active. That is the association problem the journal's own release states in the first highlights.

The practical reading, short of a cause, is the one clinics already give and now have a longer data set under. Four hours a week was better than less. Eight was better than four. Intensity, once the hours were in, did not separate the groups. A walk that gets repeated is the exposure the paper measured. A single hard session is not.

Rock Steady Boxing and similar programs have built a patient culture around that repetition. The Washington Post's photograph from a gym in Mesa, Arizona, showed Mark Loper on the battle ropes five weeks after a Lewy-body Parkinson's diagnosis. The study did not test boxing. It tested reported hours. The hours are the finding. The disease still progresses. It progressed more slowly, on these scales, in the people who kept moving.