Feasibility of a Community-Based Multimodal Exercise Programme in Parkinson's Disease

Parkinson's disease (PD) is a chronic and progressive neurodegenerative disorder characterised by motor symptoms such as bradykinesia, rigidity and tremor, as well as non-motor symptoms including pain, fatigue, sleep disturbances, cognitive impairment and psychiatric symptoms. Although pharmacological management is effective for several motor manifestations, many non-motor symptoms respond poorly to dopaminergic therapy, highlighting the need for complementary non-pharmacological interventions. Exercise therapy has shown beneficial effects on both motor and non-motor symptoms in people with Parkinson's disease. However, it remains necessary to determine whether exercise programmes supported by the scientific literature can be feasibly implemented within real-world community environments frequently attended by patients, such as Parkinson's disease associations. In these settings, exercise interventions are commonly delivered in generic group-based formats despite the substantial heterogeneity in symptom severity, functional capacity and disease progression among participants. Therefore, there is also a need to design exercise programmes that allow individualised adjustment of exercise prescription parameters, including intensity and progression criteria, in order to optimize the potential effects of exercise on Parkinson's disease symptoms while maintaining safety and feasibility in community-based group settings. The present study aims to evaluate the feasibility of implementing a multimodal, group-based but individualised therapeutic exercise programme within a real-world Parkinson's disease association setting. Feasibility outcomes include consent and recruitment rates, adherence, intervention completion, trial completion, acceptability, perceived exertion, treatment-decision rate and safety. Control group recruitment and assessment completion will be reported descriptively as operational information related to the exploratory comparison group, but they will not determine the primary feasibility assessment of the intervention. Secondary objectives are to obtain preliminary comparative information regarding the potential effectiveness of the intervention on motor and non-motor symptoms, gait, balance, physical fitness, pain-related outcomes and exercise-induced hypoalgesia. This study uses a non-randomized sequential feasibility design. Recruitment of the intervention group as a cohort was necessary to implement the group exercise programme under realistic conditions and to evaluate intervention-related feasibility outcomes. To provide preliminary comparative information regarding effectiveness, a matched non-exercise control group was included. Frequency matching will be used at the group level according to sex, 10-year age categories and Hoehn \& Yahr stage categories (1-1.5, 2-2.5 and 3). Individual 1:1 matching will not be required. This approach was selected to reduce baseline imbalance while maintaining the feasibility of recruitment within a real-world community setting. The sample size was determined according to the primary feasibility objective, specifically the precision of the estimated adherence rate. Assuming an expected adherence rate of approximately 80%, 28 participants would provide an estimation precision of approximately ±15% with a 95% confidence interval. Considering potential attrition, the intervention group sample size was increased to 32 participants. A matched non-exercise control group of 32 participants will also be recruited, resulting in a total target sample size of 64 participants. Participants with Hoehn \& Yahr stages 1-3 will be recruited from Asociación Parkinson Madrid and other Parkinson's disease associations in the Madrid region. The intervention group will participate in a 12-week multimodal exercise programme consisting of two weekly supervised face-to-face sessions and one weekly home-based session. The programme includes strength training, cardiovascular/balance exercise and cognitive-motor exercises. Exercise prescription and progression were individualised according to participant tolerance, functional capacity, motor performance, and safety considerations. Training intensity was monitored and adjusted using 10-repetition maximum principles, repetitions in reserve (RIR), and perceived exertion scales including OMNI-RES and Borg ratings. Exercise prescription and progression were individualised according to participant tolerance, functional capacity, motor performance, and safety considerations. All supervised sessions were delivered by physiotherapists experienced in neurological rehabilitation and exercise prescription for Parkinson's disease. Outcomes will be assessed at baseline, post-intervention and 6-month follow-up. Feasibility outcomes will be analysed descriptively using frequencies, percentages, means and confidence intervals where appropriate. Secondary clinical outcomes measured at baseline, post-intervention and 6-month follow-up will be analysed using linear mixed-effects models including group, time and group-by-time interaction effects. Estimated between-group differences, 95% confidence intervals and effect sizes will be reported. Given the feasibility nature of the study and the non-randomized sequential design, efficacy analyses will be interpreted as exploratory and hypothesis-generating rather than confirmatory.