BackgroundEndurance exercise improves aerobic capacity (VO2peak) 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, VO2peak, 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, VO2peak, 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 (p = 0.953), VO2peak (p = 0.965), or peak HR (p = 0.388). People randomized into the high-intensity group improved VO2peak compared to usual care (p < 0.001adj) 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 VO2peak in people with early PD apply equally to people with CI.
Keywords: aerobic capacity; chronotropic incompetence; endurance exercise; motor symptoms.
Exercise training, such as walking on a treadmill, helps improve fitness and symptoms of Parkinson's disease (PD) in those who have recently been diagnosed with PD. We aimed to determine if these beneficial effects of exercise were also experienced by those with PD who may have a hard time increasing their heart rate during an exercise test. This study looked at the effects of different intensities of 6 months of treadmill exercise and the ability to get one's heart rate up to where one might expect based on age during exercise testing on motor symptoms of PD and exercise capacity. Regardless of one's ability to increase their heart rate to an expected value based on age, individuals with early PD experienced benefits from 6 months of treadmill exercise training. This suggests that the beneficial effects of exercise training on disease progression and exercise capacity in early PD apply equally to those with normal or abnormal heart rate responses to exercise testing.