Slowing Parkinson's Early Through Exercise Dosage-United Kingdom (Slow-SPEED)

Queen Mary University of London

Status: Not yet enrolling

Conditions: Anosmia; Hyposmia

Treatments: Other: Slow-SPEED app

Study type: Interventional

Funder types: Other

Identifiers

NCT06600438

362207

Details and patient eligibility

About

Parkinson's disease (PD) is the fastest growing neurological condition worldwide and currently has no treatment that slows or prevents it. Research shows that regular exercise may help protect the brain and delay symptoms. This study will test whether a long-term, home-based exercise programme can help people who are at increased risk of Parkinson's because they have a reduced sense of smell (called "hyposmia"). Hyposmia is a common early sign that can appear years before the movement symptoms of Parkinson's.

The study, called Slow-SPEED UK, will recruit 110 adults aged 40 and over who have hyposmia and are currently not very active (walking less than 7,000 steps a day). Participants will first complete a four-week baseline period to confirm eligibility, then be randomly assigned (like flipping a coin) to one of two groups:

Full-dose exercise group - encouraged to gradually double their daily step count using a fitness tracker and smartphone app.

Low-dose control group - encouraged to increase daily steps by 10% using the same tools.

Both groups will use the study's fitness tracker and app, which provides goals, feedback, and motivation through gamification. The programme lasts 18 months, with assessments at the start, mid-point (9 months), and end (18 months). Some participants may also give optional blood or skin samples to help researchers explore biological changes linked to early Parkinson's.

The main question this study will answer is whether a remote, app-based programme can successfully increase daily step counts in people with hyposmia. Researchers will also look at whether exercise affects other outcomes such as exercise intensity, mood, sleep, smell, movement, quality of life, and early biological markers of Parkinson's.

The study is designed as a feasibility trial. This means its main goal is to test whether the programme is practical, acceptable, and safe for participants. Results will inform larger future studies that could test whether structured exercise can delay or prevent Parkinson's disease in at-risk groups. Because exercise is already known to have many health benefits, all participants are expected to gain from taking part, regardless of whether they eventually develop Parkinson's.

Full description

Background and Rationale:

Parkinson's disease (PD) is the fastest growing neurological disorder worldwide, and there are still no treatments proven to slow or prevent it. By the time PD is diagnosed, most dopamine-producing neurons in the brain are already lost. This highlights the importance of testing preventive strategies during the prodromal (early) stage, before movement symptoms appear.

One of the most common prodromal features is hyposmia (reduced sense of smell), which is present in up to 90% of people who later develop PD. Individuals with hyposmia have nearly a fourfold increased risk of developing PD, making this group an ideal target for prevention-focused research.

Evidence from laboratory and clinical studies suggests that exercise may have protective effects on the brain by promoting neuroplasticity, reducing inflammation, and improving cellular health. Exercise is already known to improve mobility, mood, sleep, and quality of life in people with PD. Observational studies also show that more active individuals are less likely to develop PD. However, structured, long-term exercise trials have not yet been conducted in hyposmic individuals at risk of PD.

Study Objectives:

The primary objective is to test the feasibility of a remote, app-based exercise programme to increase daily step counts in adults with hyposmia. Secondary objectives include examining exercise intensity, digital fitness and gait markers, smell, sleep, mood, quality of life, and optional biomarkers of PD risk. This feasibility trial will inform the design of future large-scale studies.

Study Design:

Slow-SPEED UK is a two-arm, double-blind randomised controlled trial that will recruit 110 participants aged 40 years and older with confirmed hyposmia.

All participants complete a 4-week baseline period with a Fitbit device to confirm activity levels.

Eligible participants (average <7,000 steps/day) will be randomised 1:1 to:

Full-dose group: goal to double daily steps (100% increase).

Low-dose control group: goal to increase steps by 10%.

Both groups receive the Slow-SPEED smartphone app and Fitbit, which provide gamified feedback, challenges, and motivation.

Follow-up assessments occur at baseline (in-person), 9 months (remote), and 18 months (in-person).

A subgroup will also provide blood and skin samples for exploratory biomarker studies.

The primary outcome is change in average daily step count from baseline to 18 months. Secondary measures include exercise intensity, free-living gait metrics, olfactory testing, patient-reported outcomes, and optional biomarkers.

Duration:

Each participant is enrolled for approximately 19 months (including the 4-week baseline and 18-month intervention). Recruitment is expected to take 5 months, for a total study length of about 2 years.

Risks and Benefits:

The risks are low and mainly relate to normal physical activity, such as mild muscle soreness or fatigue. Safety screening and eligibility criteria minimise risk. Unlike drug-based trials, there are no medication side effects.

The benefits are broad. Participants may gain improvements in mobility, sleep, and wellbeing regardless of PD risk. At a scientific level, the study will provide key information on whether long-term, remote exercise programmes are practical, acceptable, and safe for people with hyposmia, and whether they show early signals of benefit.

International Collaboration:

Slow-SPEED UK is part of Slow-SPEED International, a coordinated programme with parallel trials in the Netherlands (focusing on people with REM sleep behaviour disorder) and the USA (focusing on people with genetic PD risk variants such as LRRK2 or GBA1). By aligning protocols and outcome measures, the programme will enable pooled analyses across different prodromal groups. Together, these studies will build the evidence base for exercise as a low-cost, scalable strategy to delay or prevent Parkinson's disease worldwide.

Enrollment: 110 estimated patients

Sex: All

Ages: 40 to 100 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Inclusion criteria

• Age ≥ 40 years
• Objective hyposmia, defined as scoring below the 15th percentile (adjusted for age/sex) on UPSIT
• Ability and willingness to provide written informed consent
• Proficiency in written and spoken English sufficient to complete study procedures.
• Willingness and ability to attend baseline (in-person), 9-month (remote), and 18-month (in-person) assessments.
• Access to telephone or internet for interim communication. Specifically, in possession of a suitable smartphone (screen size minimum 4.6 inch; Android version 9 or iOS version 15 or newer).
• Physical activity threshold: During the 4-week eligibility run-in, the mean daily step count must be <7,000 steps/day, calculated over ≥21 valid days (a valid day = ≥10 hours wear time or ≥1,000 steps). If recruitment after the first 2 months is <60-70% of target, and subject to TSC/Sponsor approval and REC amendment, eligibility may be broadened to <10,000 steps/day (i.e. participants averaging 7,000-9,999 steps/day become eligible).

Exclusion criteria

• Clinical diagnosis of PD, dementia, or other neurodegenerative conditions
• Severe or unstable medical or psychiatric illness likely to impair participation
• Use of agents known to alter olfaction (e.g. intranasal zinc, chronic corticosteroids)
• Current enrolment in an interventional study within the past 3 months (standard research retention guidance).
• Inability to complete study procedures in English, per investigator assessment
• Unable to give consent
• Participants not living independently in the community. Participants in nursing homes, hospitalised persons on in a non-institutionalised setting are excluded.
• Subject's personal smartphone is Fitbit-incompatible i.e. Huawei P8 Lite; Huawei P9 Lite; Xiaomi Mi 6; Huawei P20 Lite
• Activity level above threshold during eligibility run-in: mean daily step count ≥7,000 steps/day (or ≥10,000 steps/day if the broadened threshold is activated).

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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110 participants in 2 patient groups

100% exercise increase

Experimental group

Description:

Arm: Full-Dose Exercise Group Participants in this arm will be asked to increase their average daily step count by 100% compared with baseline. Using a Fitbit smartwatch and the Slow-SPEED smartphone app, they will receive personalised step goals, real-time feedback, and gamified challenges to encourage gradual and sustained increases in physical activity. The programme is delivered remotely and unsupervised over 18 months, with progress monitored continuously through the wearable device.

Treatment:

Other: Slow-SPEED app

10% exercise increase

Active Comparator group

Description:

Arm: Low-Dose Control Group Participants in this arm will be asked to increase their average daily step count by 10% compared with baseline. Like the intervention group, they will use a Fitbit smartwatch and the Slow-SPEED smartphone app, receiving similar gamified feedback and motivational tools. The lower step target provides an active control condition while maintaining blinding. The programme is delivered remotely and unsupervised over 18 months, with continuous monitoring via the wearable device.

Treatment:

Other: Slow-SPEED app