Exercise can improve gait speed, muscle strength, and fitness in patients with Parkinson's disease (PD), according to results of a randomized controlled trial.
"Both treadmill exercise and resistance exercise improve symptoms of PD, but different types of exercise improve different symptoms," first author Lisa M. Shulman, MD, professor of neurology, University of Maryland School of Medicine, Baltimore, told Medscape Medical News.
"Treadmill exercise improved cardiovascular fitness. Resistance exercise improved muscle strength. And both treadmill and resistance exercise improved gait speed and mobility," she said.
The study was published online November 5 in Archives of Neurology.
Multiple Benefits
The coauthors of a linked commentary say the study "adds to the growing body of literature demonstrating the value of exercise in PD."
"Beyond its benefits on physical health, exercise gives patients a more active role in the management of their PD. Patients are thirsting for such a role," write Liana S. Rosenthal, MD, and E. Ray Dorsey, MD, from the Parkinson Disease and Movement Disorder Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.
The onset of gait impairment in patients with PD contributes to functional decline, and current therapies do little to preserve mobility as PD progresses, the authors write.
For this study, Dr. Shulman's team enrolled 67 patients with PD and mild to moderate gait or balance impairment in a prospective, randomized, single-blind clinical trial comparing 3 types of physical exercise:
Higher-intensity treadmill exercise (30 minutes at 70% to 80% of heart rate reserve);
Lower-intensity treadmill exercise (50 minutes at 40% to 50% of heart rate reserve); and
Stretching and resistance exercises (2 sets of 10 repetitions on each leg on 3 resistance machines [leg press, leg extension, and curl]).
All exercise groups trained 3 times per week for 3 months, for a total of 36 sessions under direct supervision of exercise physiologists.
The primary outcome measures were gait speed (6-minute walk, 6MW), cardiovascular fitness (peak oxygen consumption per unit time, VO2), and muscle strength (1-repetition maximum strength).
Lower-Intensity Walking Best For Gait
The researchers found that all 3 types of physical exercise improved distance on the 6MW, but the lower-intensity treadmill exercise yielded the greatest benefit (48 meters [161 feet], or 12% improvement; within-group P = .001). Stretching and resistance exercises resulted in a 9% improvement, with an increase of 32 meters (107 feet; P < .02), whereas higher-intensity treadmill exercise showed a 6% improvement, an increase of 23 meters (77 feet; P = .07).
On the basis of reports of a minimally important difference in the 6MW for older adults, the increase of distance after lower-intensity treadmill exercise is a "substantial meaningful change," the authors say, and the increases after stretching and resistance exercises and higher-intensity treadmill exercise are "greater than a small meaningful change."
Dr. Shulman said the finding that lower-intensity treadmill exercise (walking at a comfortable pace) was best for gait was "unexpected."
"The lower-intensity treadmill training was less intense but longer (50 minutes 3 times per week rather than 30 minutes 3 times per week). Therefore, the longer duration of exercise may be an important factor," she explained.
Both treadmill exercises improved peak VO2 (7% to 8% increase; P < .05) more than did the stretching and resistance exercises. Only stretching and resistance improved muscle strength (16% increase; P < .001).
No Improvement in Daily Function
"An important question," Dr. Shulman said, is whether patients with PD and early gait impairment can do these types of exercises unsupervised, outside a clinical trial.
"In this study, all patients were supervised throughout the study. The most prudent approach is that people with Parkinson's should start by speaking to their primary care physician and their neurologist about the safety of exercise. Once medical clearance is obtained, the person with PD should consider obtaining the input of a physical therapist to design an appropriate and safe individualized exercise program," she said.
Mirroring previous exercise trials in PD, in the current trial, improvements in gait speed and fitness did not translate into improvement in daily function. Neither ambulation at home, assessed using the Step Activity Monitor, nor performance on activities of daily living measured on the Schwab and England Activities of Daily Living Scale improved, despite improvement in the 6MW, the researchers report. They say it's unclear whether the extent of improvements is inadequate to improve function or whether the measures are insensitive to these changes.
There were also no changes in any exercise group for nonmotor outcomes, such as depression, fatigue, quality of life, and falls.
Nonetheless, Dr. Rosenthal and Dr. Dorsey point out in their editorial that research has shown that exercise programs among patients with neurologic disorders "increase the patients' sense of self-efficacy, their sense of involvement in their care and overall belief in their abilities to perform certain activities."
"In addition, patient involvement leads to higher satisfaction with care, and greater likelihood of following provider recommendations," they conclude. "In essence, exercise puts the patient — not a pill — at the center of care, which is exactly where patients want and ought to be."
This study was supported by a grant from the Michael J. Fox Foundation. Additional resources were provided by the Baltimore Veterans Affairs Medical Center, Geriatric Research Education and Clinical Center, the National Institute on Aging Claude D. Pepper Older Americans Independence Center, and the Veterans Affairs Office of Rehabilitation Research and Development Center for Excellence in Exercise and Robotics for Neurological Disorders. Dr. Shulman serves as editor-in-chief of the American Academy of Neurology's Neurology Now patient book series; receives royalties from Johns Hopkins University Press; and receives research support from the National Institutes of Health, the Michael J. Fox Foundation, Teva Pharmaceuticals, and the Rosalyn Newman Foundation. A complete list of author disclosures is provided with the article. Dr. Dorsey is a consultant to Lundbeck and Medtronic and receives research support from the Agency for Healthcare Research and Quality, Lundbeck, and Prana Biotechnology.
Arch Neurol. Published online November 5, 2012. Abstract Commentary
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Cite this: Exercise Has Benefits in Parkinson's Disease - Medscape - Nov 06, 2012.
