Slow-SPEED-NL: Slowing Parkinson's Early Through Exercise Dosage-Netherlands

Rationale: Parkinson's Disease (PD) is the fastest growing neurodegenerative disease. Exercise beneficially effects motor symptoms and neuroplasticity in people with PD. However, disease-slowing interventions have been ineffective in clinically manifest PD, when pathology is already advanced, but could succeed in prodromal PD, when pathology is limited. People with an isolated Rapid Eye Movement (REM) sleep Behaviour Disorder (iRBD) have a high risk to develop clinically manifest PD or a related neurodegenerative disease and are therefore considered to have probable prodromal PD. This study will take an important step forward by studying the feasibility and preliminary efficacy of long-term physical activity on prodromal symptoms and disease progression in people with probable prodromal PD using a newly developed, fully remote smartphone-based app. The app is inspired by the app used in the STEPWISE trial (NCT04848077). Objective: The goal of this clinical trial is to investigate whether a smartphone app can increase the volume and intensity of physical activity in daily life in patients with iRBD at risk of developing PD for a long period of time (24 months). The secondary aim is the potential group effect on physical fitness, digital prodromal motor- and non-motor symptoms. Thirdly, we investigate whether the intervention, prodromal motor- and non-motor symptoms can be assessed remotely in a digital, decentralized fashion. Fourthly, we aim to investigate the effect on imaging- and fluid biomarkers to identify markers for prodromal progression. Using these biomarkers, we aim to develop a composite score (prodromal load score) to estimate the total prodromal load. The anticipated fluid biomarkers outcomes are subject to potential alterations in the event of the development and implementation of novel techniques and/or biomarkers during the course of this study. Study design: Double-blind randomized controlled trial Study population: A total of 110 Dutch patients with iRBD (ICSD-3 criteria) aged 50 years and older, who are in possession of a suitable smartphone without mobility hampering conditions and absence of cognitive impairment which impedes usage of a smartphone will be recruited Intervention: Participants will be randomized to a group and will be motivated to increase the volume and intensity of physical activity based on their own baseline level. The groups differ in the amount of physical activity that they are tasked to achieve.