An interventional study of Increase of physical activity volume and intensity with the use of a motivational smartphone application in Parkinson Disease, Prodromal Stage and Neurodegenerative Diseases, sponsored by Radboud University Medical Center. Recruiting at 2 sites in 2 countries. Open to participants aged 50 Years and older. Per ClinicalTrials.gov, last updated 2026-10-15.
Sponsored by Radboud University Medical Center · Not applicable, Interventional, and Prevention
The goal of this clinical trial is two-fold. First to investigate the feasibility of whether a remotely administered smartphone app can increase the volume and intensity of physical activity in daily life in individuals with a LRRK2 G2019S or GBA1 N370S genetic mutation over a long period of time (24 months). Second, to explore the preliminary efficacy of exercise on markers for prodromal Parkinson's disease progression in individuals with a LRRK2 G2019S or GBA1 N370S genetic mutation.
Participants will be tasked to achieve an incremental increase of daily steps (volume) and amount of minutes exercised at a certain heart rate (intensity) with respect to their own baseline level. Motivation with regards to physical activity will entirely be communicated through the study specific Slow Speed smartphone app. A joint primary objective consists of two components. First to determine the longitudinal effect of an exercise intervention in LRRK2 G2019S or GBA1 N370S variant carriers on a prodromal load score, comprised of digital biomarkers of prodromal symptoms. The secondary component of the primary outcome is to determine the feasibility of a remote intervention study. The secondary objective is the effect of a physical activity intervention on digital markers of physical fitness. Exploratory outcomes entail retention rate, completeness of remote digital biomarker assessments, digital prodromal motor and non-motor features of PD. Using these biomarkers, the investigators aim to develop a composite score (prodromal load score) to estimate the total prodromal load. An international exercise study with fellow researchers in the United Kingdom are currently in preparation (Slow-SPEED-UK) and active in the Netherlands (Slow-SPEED-NL). Our intention is to analyse overlapping outcomes combined where possible through a meta-analysis plan, to obtain insight on (determinants of) heterogeneity in compliance and possible efficacy across subgroups
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 a LRRK2 G2019S or GBA1 N370S genetic mutation have an increased risk to develop clinically manifest PD. Therefore, this group is likely to develop 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 prodromal PD using a newly developed, fully remote smartphone-based app. The app is inspired by the app used in the STEPWISE trial (NCT04848077) and currently used in Slow-SPEED-NL (NCT06193252).
Objective: The joint primary objective has two components. First, to evaluate the long-term (36-month) impact of an exercise intervention on a prodromal load score in individuals carrying the LRRK2 G2019S or GBA1 N370S variants. This score will be derived from digital biomarkers capturing both motor and non-motor prodromal symptoms. Using these biomarkers, the investigators aim to develop a composite prodromal load score to estimate the overall burden of prodromal features.
The secondary component of the primary outcome is to determine the feasibility of a long-term (36 months) remote intervention study expressed as longitudinal change in digital measures of physical activity (step count) measured using a Fitbit smartwatch.
Our secondary objective is the potential group effect on physical fitness. Thirdly, the investigators investigate whether the intervention, prodromal motor- and non-motor symptoms can be assessed remotely in a digital, decentralized fashion.
Currently blood- and imaging biomarkers are not incorporated as outcome measures. The investigators intend to add these biomarkers pending appropriate funding.
Study design: Double-blind randomized controlled trial
Study population: A total of 600 English speaking individuals living in the United States of America with a LRRK2 G2019S or GBA1 N370S genetic mutation 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. Participant recruitment will primarily target individuals from the 23andMe customer base. Enrollment and onboarding of study participants will be supported by research staff at the University of Rochester.
Intervention: Participants will be randomized to a group (1:1 ratio) and will be motivated to increase the volume and intensity of physical activity based on their own baseline level. Baseline physical activity levels will be determined during a 4-week period. The two groups differ in the amount of physical activity that they are tasked to achieve.
4,573 studies on the registry are indexed under Parkinson Disease; 1,086 are open to participants now.
This study's planned enrollment of 600 is above the median of 40 across 3,353 interventional studies indexed under Parkinson Disease.
Browse Parkinson Disease studies →Radboud University Medical Center is the lead sponsor of 986 studies on the registry; 136 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
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Exclusion criteria
Behavioral: Increase of physical activity volume and intensity with the use of a motivational smartphone application
Behavioral: Increase of physical activity volume and intensity with the use of a motivational smartphone application
A motivational smartphone application will be available for all participants using their own smartphone: the Slow-SPEED app. The Slow-SPEED app will motivate participants to increase the volume and intensity of their physical activity in daily life over a long period of time (2 years) based on their own baseline levels. Different treatment arms will receive different physical activity goals. The app offers participants feedback and support, that will stimulate them to reach their individual physical activity goal (i.e. incremental relative increase of step count and minutes exerting ≥ 64% of maximum heart rate reflecting moderate-to-vigorous physical activity (MVPA) relative to baseline level).
Change in composite prodromal load score
Change in prodromal load score, comprised of digital biomarkers for prodromal symptoms. The score is currently under development.
Time frame: From inclusion (week 0) to the end of treatment (week 156)
Mean change in step count per day
Mean change in step count per day as measured continuously with a smartwatch. Mean steps per day will be calculated from 4-week periods. Higher positive change in step count indicate more volume of physical activity.
Time frame: All 4 week periods between and including week -4 until 0 (baseline period) and week 152 until 156 (end of treatment)
Change in moderate to vigorous physical activity (MVPA) per day
Change in number of minutes exerting (minimally) ≥ 64% of maximum heart rate, reflecting moderate intense physical activity, measured continuously using a smartwatch. Mean minutes per day will be calculated from 4-week periods. Higher positive change in minutes of MVPA indicate more aerobic physical activity.
Time frame: All 4 week periods between and including week -4 until 0 (baseline period) and week 152 until 156 (end of treatment)
Change in resting heart rate (physical fitness)
Change in resting heart rate per day as measured continuously with a smartwatch. Mean resting heart rate per day will be calculated from 4-week periods. Higher negative change (i.e. lower resting heart rate) indicate better function.
Time frame: All 4 week periods between and including week -4 until 0 (baseline period) and week 152 until 156 (end of treatment)
Change in heart rate variability (physical fitness & autonomic function)
Change in heart rate variability in Root Mean Square of Successive Differences (RMSSD) measured every 5 minutes with a smartwatch. Mean RMSSD per day will be calculated from 4-week periods. Higher positive change in RMSSD indicate better function.
Time frame: All 4 week periods between and including week -4 until 0 (baseline period) and week 152 until 156 (end of treatment)
Change in VO2max (physical fitness)
Change in VO2max in ml/kg/min measured per day with a smartwatch. Mean VO2max per day will be calculated from 4-week periods. Higher positive change in VO2max indicate better function.
Time frame: All 4 week periods between and including week -4 until 0 (baseline period) and week 152 until 156 (end of treatment)
Change in anxiety and depression (HADS)
Change from baseline (week 0) on the Hospital Anxiety and Depression Scale (HADS) at week 52 (1 year) and week 104 (2 years), and week 156 (end of treatment). Total range 0-42. Divided Anxiety and Depression scale have a range of 0-21. Higher scores indicate worse function.
Time frame: Week 0 (baseline), week 52 (1 year), week 104 (2 years), week 156 (end of treatment)
Change in cognition (CANTAB web-version)
Change from baseline (week 0) on the Cambridge Neuropsychological Test Automated Battery (CANTAB) at week 52 (1 year), week 104 (2 years) and week 156 (end of treatment). More errors indicate worse function.
Time frame: Week 0 (baseline), week 52 (1 year), week 104 (2 years), week 156 (end of treatment)
Mean change in light sleep (sleep stage)
Mean change in light sleep stage measured continuously with a smartwatch. Mean duration of light sleep per day will be calculated from 4-week periods. Higher positive change indicate more light sleep.
Time frame: All 4 week periods between and including week -4 until 0 (baseline period) and week 152 until 156 (end of treatment)
Mean change in deep sleep (sleep stage)
Mean change in deep sleep stage measured continuously with a smartwatch. Mean duration of deep sleep per day will be calculated from 4-week periods. Higher positive change indicate more deep sleep.
Time frame: All 4 week periods between and including week -4 until 0 (baseline period) and week 152 until 156 (end of treatment)
Mean change in REM sleep (sleep stage)
Mean change in rapid eye movement (REM) sleep stage measured continuously with a smartwatch. Mean duration of REM sleep per day will be calculated from 4-week periods. Higher positive change indicate more REM sleep.
Time frame: All 4 week periods between and including week -4 until 0 (baseline period) and week 152 until 156 (end of treatment)
Change in self-reported sleep quality (PSQI)
Change from baseline (week 0) on the Pittsburgh Sleep Quality Index (PSQI) at week 52 (1 year) and week 104 (2 years), and week 156 (end of treatment). Range 0-21. Higher scores indicate worse sleep quality.
Time frame: Week 0 (baseline), week 52 (1 year), week 104 (2 years), week 156 (end of treatment)
Change in REM-sleep behavior disorder (RBDSQ)
Change in question of the REM-sleep behavior disorder (RBD) single screening questionnaire (RBDSQ) at week 52 (1 year) and week 104 (2 years), and week 156 (end of treatment). 'Yes' indicates a higher likelihood of having RBD.
Time frame: Week 0 (baseline), week 52 (1 year), week 104 (2 years), week 156 (end of treatment)
Change in olfaction (UPSIT)
Change from baseline (week 0) on the University of Pennsylvania Smell Identification Test (UPSIT) at week 156 (end of treatment). Range 0-40. Higher scores indicate better function.
Time frame: Week 0 (baseline), week 156 (end of treatment)
Change in motor symptoms (Roche PD Research mobile application)
Change in motor symptoms measured digitally with the smartphone using the Roche PD Research mobile application. Higher scores indicate worse function. 6-weekly testing interval. Optional to complete the tests weekly.
Time frame: Week 0, Week 6, Week 12, Week 18, Week 24, Week 30, Week 36, Week 42, Week 48, Week 54, Week 60, Week 66, Week 72, Week 78, Week 84, Week 90, Week 96, Week 102, Week 108, Week 114, Week 120, Week 126, Week 132, Week 138, Week 144, Week 150, Week 156
Change in instrumental activities of daily living (ADL) (functional status)
Change from baseline (week 0) on Lawton instrumental ADL (iADL) scale at week 52 (1 year) and week 104 (2 years), and week 156 (end of treatment). Range 0-14. Higher score indicate better function.
Time frame: Week 0 (baseline), week 52 (1 year), week 104 (2 years), week 156 (end of treatment)
Change in WHOQoL-BREF (quality of life)
Change from baseline (week 0) on World Health Organization Quality of Life Questionnaire - BREF (WHOQoL-BREF) scale at week 52 (1 year) and week 104 (2 years), and week 156 (end of treatment). Range 0-100. Higher score indicate better quality of life.
Time frame: Week 0 (baseline), week 52 (1 year), week 104 (2 years), week 156 (end of treatment)
Change in Research and Development (RAND-36)/Short Form health survey (SF-36) (quality of life)
Change from baseline (week 0) on RAND-36/SF-36 scale at week 52 (1 year) and week 104 (2 years), and week 156 (end of treatment). Range 0-100. Higher score indicate better quality of life.
Time frame: Week 0 (baseline), week 52 (1 year), week 104 (2 years), week 156 (end of treatment)
Change in MDS-UPDRS part 1b (Non-Motor Experiences of Daily Living)
Change from baseline (week 0) on MDS-UPDRS part 1b scale at week 52 (1 year) and week 104 (2 years), and week 156 (end of treatment). Range 0-24. Higher score indicate worse function.
Time frame: Week 0 (baseline), week 52 (1 year), week 104 (2 years), week 156 (end of treatment)
Change in MDS-UPDRS part 2 (Motor Experiences of Daily Living)
Change from baseline (week 0) on MDS-UPDRS part 2 at week 52 (1 year) and week 104 (2 years), and week 156 (end of treatment). Range 0-56. Higher score indicate worse function.
Time frame: Week 0 (baseline), week 52 (1 year), week 104 (2 years), week 156 (end of treatment)
System Usability (SUS)
Usability of the Slow-SPEED smartphone application assessed by the System Usability Scale (SUS) at week 52 (1 year) and week 104 (2 years), and week 156 (end of treatment). Range 0-100. Higher score indicate better usability.
Time frame: Week 0 (baseline), week 52 (1 year), week 104 (2 years), week 156 (end of treatment)
Barriers and motivators to engage in physical activity
Barriers and motivators to engage in physical activity reported on a self-developed questionnaire. Section 1: Exercise history (qualitative), section 2: Overall motivation to exercise (0-10, higher score indicates higher motivation), section 3: Specific motivations to exercise (0-14, higher score indicaties more motivational factors), Section 4: barriers to exercise (0-20, higher score indicates more barriers), Section 5: Main motivations and barriers to exercise (qualitative).
Time frame: Week 0 (baseline) and week 156 (end of treatment)
Change in phenoconversion neurodegenerative disease (0-100%)
Change from baseline (week 0) on phenoconversion in Parkinson's Disease (PD), Lewy body dementia (LBD) and multiple system atrophy (MSA) at week 156 (end of treatment). Higher scores indicate more phenoconversion.
Time frame: Week 0 (baseline) and week 156 (end of treatment)
Change in REM-sleep behavior disorder diagnosis
Change from baseline (week 0) on diagnoses of REM-sleep behavior disorder (rBD). Higher scores indicate more RBD diagnoses.
Time frame: Week 0 (baseline) and week 156 (end of treatment)
Change in step count on a group level (compliance)
Change from week -4 until 0 (baseline period) mean step count per day compared to mean step count in 6 month periods. Mean step count per day will be calculated from 4-week periods. Scored as number of participants able to increase step count per day 0-25%, 26-50%, 51-75%, 76-100% relative to their own baseline measure
Time frame: Week -4 until 0 (baseline) compared to week 0-26, week 26-52, week 52-78, week 78-104, Week 104-130, Week 130-156
Change in moderate to vigorous physical activity per day on a group level (compliance)
Change from week -4 until 0 (baseline period) number of minutes exerting (minimally) ≥ 64% of maximum heart rate in 6 month periods. Mean minutes per day will be calculated from 4-week periods. Scored as number of participants to increase 0-25%, 26-50%, 51-75%, 76-100% relative to their own baseline measure
Time frame: Week 0-26, Week 26-52, Week 52-78, Week 78-104, Week 104-130, Week 130-156
Number of completed step week goals on a group level (compliance)
Total number of completed step count week goals
Time frame: Week 0 (baseline) and week 156 (end of treatment)
Number of completed aerobic activity (MVPA intensity) week goals on a group level (compliance)
Total number of completed aerobic activity (MVPA intensity) week goals
Time frame: Week 0 (baseline) and week 156 (end of treatment)
Number of drop-outs on a group level (retention rate)
Number of drop-outs throughout the study
Time frame: Week 0 (baseline), week 26, week 52, week 78, week 104, week 130, week 156 (end of treatment)
Number of interactions with Slow-SPEED app on a group level
Total times opening the app
Time frame: Week 0 (baseline), week 26, week 52, week 78, week 104, week 130, week 156 (end of treatment)
Number of completed questionnaires on group level (completeness of digital assessments)
Number of completed questionnaires
Time frame: Week 0 (baseline), week 52 (1 year), week 104 (2 years), week 156 (end of treatment)
Number of smartwatch data points on group level (completeness of digital assessments)
Number of data points received for each selected smartwatch parameter
Time frame: Week 0 (baseline), week 26, week 52, week 78, week 104, week 130, week 156 (end of treatment)
Total smartwatch wear time on group level (completeness of digital assessments)
Total smartwatch wear time
Time frame: Week 0 (baseline), week 26, week 52, week 78, week 104, week 130, week 156 (end of treatment)
Number of Roche PD Research mobile application data points on group level (completeness of digital assessments)
Number of data points received
Time frame: Week 0, Week 6, Week 12, Week 18, Week 24, Week 30, Week 36, Week 42, Week 48, Week 54, Week 60, Week 66, Week 72, Week 78, Week 84, Week 90, Week 96, Week 102, Week 108, Week 114, Week 120, Week 126, Week 132, Week 138, Week 144, Week 150, Week 156
Plan to share: Yes — We will make relevant anonymised data available in a database.
Supporting information: Study protocol
Time frame: We will make relevant anonymised data available in a database after publication of the main results of our trial.
Access criteria: Researchers who are interested in re-use of the data are asked to contact the central contact person for permission.
Started Sep 2025 (actual). Primary completion is estimated for Jun 2029, 45 months after the start.
Of 1,291 non-industry interventional studies with no phase under Parkinson Disease, half reached primary completion within 24 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 44. This study's planned 45 months is above that.
Counting every sponsor, half of 1,367 studies reached it within 25 months; a quarter within 11 and three quarters within 44.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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