Research News

Researchers in the Department of Biomedical Engineering have found that high-intensity aerobic exercise may help improve bimanual dexterity among patients with Parkinson's disease (PD). Patients who have PD commonly have tremors in their limbs and/or difficulty with muscular coordination.

These findings, published in Parkinsonism & Related Disorders, are the latest to come out of the CYCLE (Cyclical Lower Extremity Exercise) Trial, led by Jay Alberts, PhD. To date, his team has found that cycling programs confer significant motor, cognitive and cardiovascular benefits. Adding to this laundry list of benefits, the researchers now report that high-intensity cycling may also enhance PD patients' ability to complete common tasks of daily living such as opening containers or fastening buttons.

"Following a diagnosis, neurologists often encourage Parkinson's disease patients to exercise, but patients aren't given specific parameters for which to aim," said the study's first author Liz Jansen, MPH. "Specific exercise recommendations targeted at symptom reduction provide patients with an empowering tool in their toolbox and a proactive approach to PD symptom management."

Forced vs. voluntary exercise

In the CYCLE Trial, PD patients were divided into three groups: voluntary exercise, forced exercise (in which a motorized cycle helped riders achieve a pedaling rate approximately 30% greater than the voluntary group) and a control group. Participants in both exercise groups rode a stationary cycle three times a week for eight weeks, with the goal to maintain between 60 and 80% of their heart rate reserve (the difference between normal and maximum heart rates).

All three groups took part in measured manual dexterity tasks before and after the trial, as well as eight weeks post-intervention. Specifically, participants were tested on their ability to disconnect two objects connected by an electromagnet.

Exercise may provide double the benefits

Both exercise groups experienced improvements in the coordination of bimanual grasping forces. Specifically, their total task time improved by nearly 30% from the start to the end of the intervention. The subjects in the forced exercise group also had greater coordination of intralimb grasping forces. Importantly, the improvements in grasping abilities were still present at eight weeks after the end of the trial, suggesting long-term benefits on central nervous system functioning.

Participants demonstrated high compliance in regards to attendance and exercise parameters for the exercise intervention, showing that PD patients can safely exercise at a high level of intensity. Subjects in both groups demonstrated improvements in clinical ratings scores as measured by the Movement Disorders Society Unified Parkinson's Disease Rating Scale after the exercise intervention. The benefits were sustained (albeit at a lower level) post-intervention.

"The results from this study and our previous work demonstrate that Parkinson's disease patients can safely exercise at high intensity to help reduce the symptoms of their disease," said Jansen. "Giving patients a proactive approach to disease management empowers them and gives them the resources and information they need."

This study was supported in part by the National Institute of Neurological Disorders and Stroke, a part of the National Institutes of Health.