To assess 30 active people (15 with PD, 15 without) before and after 30 minutes of pedaling exercise using EEG-EMG, cognitive, mood and motor assessments.

Purpose: To assess 15 subjects with PD and 15 healthy controls, who exercise on a regular basis, before, during and after 30 minutes of pedaling exercise intervention. The investigators will assess subjects for alterations in motor cortex assessment, cognition and mood as measured by EMG/EEG, motor assessment and several batteries of questionnaires. Findings from this study will lay the foundation for long-term studies.

Hypotheses: The investigators anticipate to observe an altered involvement of motor cortex during steady pedaling in individuals suffering from PD. In healthy control subjects it is anticipated that changes in cognition will be observable.

Justification: Hindered movement initiation and continuing locomotion is a common syndrome in PD with profound impact on the patient's mobility and quality of life. So far, the underlying pathophysiology is not completely understood. Since the observation that cortical activity contributes to the muscle activity during locomotion-like tasks underpins the importance of corticospinal function in humans, it is of importance to examine whether this cortical involvement is altered and displays abnormalities in patients with PD. Thus, the approach of corticomuscular coupling during a locomotion-like task would allow for better understanding of the pathophysiology of PD, a prerequisite to develop therapies. Findings of this study will lay the foundation for future long-term studies.

Additionally, by examining the oscillatory EEG patterns during the exercise intervention, the investigator will be able to read out the dose response curve in real time, which will provide information on the optimum intensity and duration of exercise. Findings will help to design future studies and to develop efficient exercise therapy interventions for people with PD.

People living with PD often suffer from cognitive decline, depression, and fatigue. By assessing cognitive function before and after the exercise intervention, there will be laid a foundation for future studies investigating the effect of exercise on cognition. The collected pilot data will be relevant to learn more about the effects of exercise on mood and fatigue as well as concomitant obstacles and facilitators during exercise interventions in patients with PD.

Objectives: The primary objective of this study is to investigate if activity that arises in the motor cortex and contributes to the muscle activity during moderate pedaling is altered in patients with PD compared to healthy gender- and age-matched controls. Thus, to better understand the role of the motor cortex and its contribution in simple automated repetitive tasks in patients with PD there will be analysis of the coherence of the coupling between EEG and EMG from active leg muscles during cycling on a stationary bicycle both in subjects with PD and age and gender matched healthy controls.

Inclusion Criteria:

• Adult between 40-80 years
• Hoehn and Yahr stage I-III
• Exercise on a regular basis (at least 100 minutes of aerobic exercise per week)
• Montreal Cognitive Assessment score >/= 24
• Able to communicate with study personnel
• Able to be informed of the nature of the study and willing to give written consent form

Exclusion Criteria:

• Hoehn and Yahr stages IV-V
• Significant cardiovascular disease
• Previous stroke
• Not exercising on a regular basis
• Functional disabling dyskinesia
• Functional disabling dystonia
• Smoker
• Significant neurological or psychiatric illness other than PD
• Dementia
• Severe depression
• Significant musculoskeletal disorder (e.g. arthritis)
• Significant metabolic disorder (e.g. diabetes)
• Brain surgery in the past
• Currently taking beta blocker medication

The assessor will be blinded to subject group and intervention.