Effect of Aerobic Exercise on Cardiopulmonary Responses and Predictors of Change in Individuals With Parkinson's Disease

Objective To determine the effect of aerobic exercise on maximal and submaximal cardiopulmonary responses and predictors of change in individuals with Parkinson's disease (PD). Design Single-center, parallel-group, rater-blind study. Setting Research laboratory. Participants Individuals with mild to moderate PD (N=100). Intervention Participants were enrolled in a trial evaluating the effect of cycling on PD and randomized to either voluntary exercise (VE), forced exercise (FE), or a no exercise control group. The exercise groups were time and intensity matched and exercised 3×/wk for 8 weeks on a stationary cycle. Main Outcome Measures Cardiopulmonary responses were collected via gas analysis during a maximal graded exercise test at baseline and post intervention. Results Exercise attendance was 97% and 93% for the FE and VE group, respectively. Average exercise heart rate reserve was 67%±11% for FE and 70%±10% for VE. No significant difference was present for change in peak oxygen consumption (VO2peak) post intervention, even though the FE group had a 5% increase in VO2peak. Both the FE and VE groups had significantly higher percentage oxygen consumption per unit time ( V ˙ o2) at ventilator threshold (VT) than the control group compared with baseline values (P=.04). Mean V ˙ O2 at VT was 5% (95% CI, 0.1%-11%) higher in the FE group (P=.04) and 7% (2%, 12%) higher in VE group compared with controls. A stepwise linear regression model revealed that lower age, higher exercise cadence, and lower baseline VO2peak were most predictive of improved VO2peak. The overall model was found to be significant (P<.01). Conclusions Peak and submaximal cardiopulmonary function may improve after aerobic exercise in individuals with PD. Lower age, higher exercise cadence, and lower baseline VO2peak were most predictive of improved VO2peak in this exercise cohort. The improvements observed in aerobic capacity were gained after a relatively short aerobic cycling intervention.