Objectives-To obtain preliminary data on the effects of high-intensity exercise on functional performance in people with Parkinson's disease (PD) relative to exercise at low and no intensity; and to determine whether improved performance is accompanied by alterations in corticomotor excitability as measured through transcranial magnetic stimulation (TMS).Design-Cohort (prospective), randomized controlled trial. Setting-University-based clinical and research facilities.Participants-Thirty people with PD, 3 years or more since diagnosis, with Hoehn and Yahr stage 1 or 2.Interventions-Subjects were randomized to high-intensity exercise using body weight-supported treadmill training, low-intensity exercise, or a zero-intensity education group. Subjects completed 24 exercise sessions over 8 weeks and had 5 education classes over 8 weeks. Main Outcome Measures-UnifiedParkinson's Disease Rating Scales (UPDRS), biomechanic analysis of self-selected, fast walking, and sit-to-stand tasks; corticomotor excitability was assessed with cortical silent period durations (CSP) in response to single-pulse TMS.Results-A small improvement in total and motor UPDRS was observed in all groups. Highintensity group subjects demonstrated postexercise increases in gait speed, step and stride length, and hip and ankle joint excursion during self-selected and fast gait and improved weight distribution No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated. SuppliersPublisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptArch Phys Med Rehabil. Author manuscript; available in PMC 2010 November 22. Published in final edited form as:Arch Phys Med Rehabil. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript during sit-to-stand. Improvements in gait and sit-to-stand measures were not consistently observed in low-and zero-intensity groups. Importantly, the high-intensity group demonstrated lengthening in CSP.Conclusions-The findings suggest the dose-dependent benefits of exercise and that highintensity exercise can normalize corticomotor excitability in early PD. KeywordsBasal ganglia; Central nervous system; Neuronal plasticity; Rehabilitation; Walking Both basic research and clinical studies suggest that high intensity (ie, high repetition, velocity, complexity) is a characteristic of exercise that may be important in promoting activitydependent neuroplasticity of the injured brain, includin...

Objective: To determine whether falls can be prevented with minimally supervised exercise targeting potentially remediable fall risk factors, i.e., poor balance, reduced leg muscle strength, and freezing of gait, in people with Parkinson disease.Methods: Two hundred thirty-one people with Parkinson disease were randomized into exercise or usual-care control groups. Exercises were practiced for 40 to 60 minutes, 3 times weekly for 6 months. Primary outcomes were fall rates and proportion of fallers during the intervention period. Secondary outcomes were physical (balance, mobility, freezing of gait, habitual physical activity), psychological (fear of falling, affect), and quality-of-life measures.Results: There was no significant difference between groups in the rate of falls (incidence rate ratio [IRR] 5 0.73, 95% confidence interval [CI] 0.45-1.17, p 5 0.18) or proportion of fallers (p 5 0.45). Preplanned subgroup analysis revealed a significant interaction for disease severity (p , 0.001). In the lower disease severity subgroup, there were fewer falls in the exercise group compared with controls (IRR 5 0.31, 95% CI 0.15-0.62, p , 0.001), while in the higher disease severity subgroup, there was a trend toward more falls in the exercise group (IRR 5 1.61, 95% CI 0.86-3.03, p 5 0.13). Postintervention, the exercise group scored significantly (p , 0.05) better than controls on the Short Physical Performance Battery, sit-to-stand, fear of falling, affect, and quality of life, after adjusting for baseline performance.Conclusions: An exercise program targeting balance, leg strength, and freezing of gait did not reduce falls but improved physical and psychological health. Falls were reduced in people with milder disease but not in those with more severe Parkinson disease.