Effects of 6 months of endurance exercise on motor function, exercise capacity, and autonomic function based on presence of autonomic dysfunction in individuals with early Parkinson's disease.

BackgroundEndurance exercise improves aerobic capacity (VO) and motor symptoms in people with early Parkinson's disease (PD). Some people with PD exhibit signs of chronotropic incompetence (CI), which may impact exercise-induced benefits.ObjectiveWe investigated whether CI in people with early PD influences the change in motor signs, VO, and peak heart rate (HR) following 6 months of endurance exercise.MethodsWe performed secondary analyses of the Study in Parkinson's Disease of Exercise (SPARX), which randomized people with early PD into a high-intensity endurance exercise [80-85% of peak HR], moderate-intensity endurance exercise [60-65% of peak HR], or usual care group. MDS-UDPRS Part 3 score, VO, and heart rate (HR) response to maximal cardiopulmonary exercise testing (CPET) were analyzed at baseline and following 6 months of exercise. Participants were divided into three groups: 1) normal chronotropic response at baseline, 2) CI at baseline, and 3) taking medications with a known negative chronotropic effect regardless of CI status.ResultsData from 119 individuals (64.0 ± 9.0 years, 57.1% male, 0.3 years since diagnosis [median]) were analyzed. There were no differences among the groups in change in MDS-UPDRS motor score (= 0.953), VO (= 0.965), or peak HR (= 0.388). People randomized into the high-intensity group improved VO compared to usual care (< 0.001) regardless of CI status.ConclusionsBaseline CI did not alter responses to endurance exercise in those with early PD, suggesting that the beneficial effects of endurance exercise on disease progression and VO in people with early PD apply equally to people with CI.