Physical Functioning After 1, 3, and 5 Years of Exercise Among People With Parkinson's Disease: A Longitudinal Observational Study
Authors: States Rebecca A. , Sweeny Theresa L. , Rossi Amerigo , Spierer David K. , Salem Yasser 
Published: April 2016

Background and Purpose:
Regular physical activity is thought to be crucial to maintaining optimal physical function in people with Parkinson's disease (PWP), and it may have neuroprotective effects. As with many medical treatments, exercise is most effective when performed consistently over a period of years. The primary aim of this study was to examine multiyear adherence to a community-based group exercise program for PWP. A secondary aim was to document how physical functioning progressed after 1, 3, and 5 years for participants who consistently attended a community-based, group, exercise program.

Methods:
Forty-six individuals with idiopathic Parkinson's disease, who were at modified Hoehn and Yahr stage I, II, or III and were community ambulators, were recruited on a rolling basis between 2008 and 2013. Each provided yearly medical clearance to exercise. Participants engaged in a free, community-based, group exercise program offered 2 days per week, 1 hour per day, for three 10-week sessions per year. The program included supervised floor exercises for balance, coordination, strength, and flexibility along with resistance training on dual-action exercise machines. Participants who attended more than half the classes for 1, 3, or 5 years (n = 27, n = 14, n = 7, respectively) were considered to have completed the fitness program (consistent exercisers) and were included in the longitudinal data analysis; participants who either dropped out or attended less than half the classes (n = 19) were not included. Physical functioning was evaluated at baseline for all participants and yearly thereafter for consistent exercisers. Wilcoxon signed rank tests were used to compare baseline data with data collected after 1, 3, and 5 years of consistent exercise.

Results and Discussion:
Over half of the participants initially evaluated completed at least 1 year of the fitness program (27 of the 46 = 59%) and a proportion completed 3 years (14 of the 39 = 39%), and 5 years (7 of the 24 = 29%). At baseline, consistent exercisers were younger than those who dropped out (63.9 vs 69.9 years, P < .05), but had similar modified Hoehn and Yahr medians (2.0 vs 2.3), and similar time since diagnosis (8.0 vs 5.6 years). Consistent exercisers showed small statistically significant improvements in grip strength (8.9% change), Berg Balance scores (5.1% change), and 6-minute walk test (11% change) from baseline to year 1. No significant differences were found in these variables after 3 or 5 years, or for gait speed and timed up and go after 1, 3, or 5 years.

Conclusion:
Despite the progressive nature of Parkinson's disease, many PWP can sustain a regular program of varied modes of community-based, group exercise over a period of years. Participants who did so maintained initial performance levels on key measures of physical functioning. By working with an interprofessional team in a supportive community-based exercise program, physical therapists can help many PWP engage in consistent and sustained exercise activity over multiyear periods.