This study focuses on promoting physical activity (PA) through the implementation of a Community Physical Exercise Program for Chronic Diseases (CPEP-CD), targeting individuals aged 50 years and older with at least two of the following conditions: cardiovascular and/or cerebrovascular disease or risk (CVD), overweight, diabetes mellitus (DM), and musculoskeletal diseases. The primary objective is to improve muscle and cardiorespiratory health and well-being, while also contributing to a more objective and evidence-based exercise prescription for these pathological conditions.

Population ageing is a global challenge associated with an increased prevalence of chronic diseases that compromise quality of life (QoL). A sedentary lifestyle is linked to declines in muscle function and cardiorespiratory fitness and is considered a major risk factor for morbidity and mortality. Consequently, physical exercise is widely recommended as a key non-pharmacological intervention across multiple chronic diseases.

According to World Health Organization (WHO) guidelines, regular PA is a protective factor in the prevention and management of non-communicable diseases, including cardiovascular and cerebrovascular diseases and DM. In addition, PA provides mental health benefits, supports healthy weight maintenance, and enhances overall well-being. In adults, regular PA is associated with reductions in all-cause mortality, cardiovascular mortality, and the incidence of hypertension.

Within this context, the aim of this project is to implement a community-based physical exercise program for individuals with chronic disease and multimorbidity, focusing on CVD and cerebrovascular disease or risk, DM, and OA. The program integrates existing exercise prescription guidelines while personalizing exercise progression according to both disease-specific and multimorbidity profiles. The primary outcomes include improvements in cardiorespiratory fitness, muscular strength, bone health, functional capacity, and QoL. Additionally, through individualized training monitoring, this study seeks to establish an exercise prescription tailored to the most prevalent combinations of chronic diseases, thereby providing more objective and practical guidance for family physicians, exercise professionals, and rehabilitation specialists, and supporting more personalized and targeted exercise-based strategies for chronic disease prevention and management.

The implementation of exercise programs in individuals with chronic disease is essential for modifying cardiovascular and metabolic risk factors. However, it is equally important to examine not only the direct effects of exercise on health and well-being outcomes, but also to quantify the most appropriate training load, particularly in the presence of multimorbidity.

This is a non-pharmacological clinical study with two parallel intervention groups and a pre-post study design. Participants allocated to the Exercise Group (EG) will undertake a 12-week supervised physical exercise program, while those in the Control Group (CG) will receive no intervention during the study period.

Both groups will be assessed at two time points: (1) baseline assessment (T0) and (2) post-intervention assessment after 12 weeks (T12). The Community Physical Exercise Program (CPEP) will last 12 weeks, with two sessions per week, each lasting 60 minutes. International and national exercise prescription guidelines will be applied for each clinical condition, namely cardiovascular and/or cerebrovascular disease or risk, diabetes mellitus, and osteoarthritis. All variables will be assessed and monitored by qualified health and exercise professionals using reliable and validated instruments and equipment.

The training sessions will combine cardiorespiratory exercises aimed at improving aerobic capacity with strength training, particularly resistance exercises, using body weight and auxiliary equipment. Training intensity zones will be individualized and defined according to each participant's baseline cardiorespiratory fitness test results and subjective perception of effort.

The sample will include individuals aged 50 years or older with at least one of the aforementioned chronic conditions. Participation will be voluntary, and recruitment will be conducted through dissemination materials placed in senior universities, institutions and associations, municipalities, parish councils, sports facilities, health centers, and other relevant public spaces.

The sampling process will consist of an initial phase of non-random purposive sampling, followed by a second phase using snowball sampling if necessary. Sample size was calculated using G*Power software (version 3.1.9.7), assuming a two-tailed α level of 0.05, an effect size of 0.5, statistical power of 80%, and an anticipated dropout rate of 15%. A total sample of 147 participants will be required, with 74 participants allocated to each group.

Cardiovascular risk screening will be conducted based on the presence of one or more of the following risk factors: hypertension, dyslipidemia, or smoking, in accordance with SCORE2 or SCORE2-OP. For the other pathological conditions, definitions and criteria will be used in accordance with the recommendations of European or American scientific societies.

Following the intervention, the expected outcomes include improvements in cardiorespiratory fitness, muscular strength and muscle function, bone health, joint pain, physical function, quality of life, biochemical parameters related to glycemic and lipid profiles, and body composition. Additionally, the study aims to quantify the average training load and its progression over the intervention period.

Inclusion Criteria:

• Adults aged ≥50 years;
• At least 2 of the following: Prior cardiovascular disease (>12 months); High cardiovascular risk (SCORE2 or SCORE2 O.P.); Post-stroke (ischemic or hemorrhagic) with treated etiology; Type 2 Diabetes (> 6 months, ADA); Osteoarthristis (clinical signs/symptoms, NICE); Overweight/Obesity (BMI ≥ 27 kg/m2).
• Autonomous walking.
• Able to provide informed consent.
• Stable medications for ≥ 3 months (related to diagnoses of interest).
• Physical activity below WHO recommendations.
• No contraindications to exercise (cardiovascular, cerebrovascular, respiratory, musculoskeletal) according to ACSS.

Exclusion Criteria:

• Moderate to severe cognitive impairment - Montreal Cognitive Assessment (MoCA).
• Type 2 Myocardial Infarction.
• Class III or IV angina (Canadian Cardiovascular Society).
• Class III or IV angina (New York Heart Association).
• Uncontrolled CVD: symptomatic arrhythmias with hemodynamic compromise; severe symptomatic aortic valve stenosis; uncontrolled symptomatic heart failure; endocarditis, pericarditis, or active myocarditis; acute aortic syndrome; suspected or known dissecting aneurysm; acute systemic infections.
• Pacemaker user.
• Neurological disorders affecting gait.
• Severe diabetes-related complications contraindicating exercise (poor metabolic control, diabetic foot, diabetic retinopathy, diabetic nephropathy, and diabetic autonomic neuropathy).
• Recent use of insulin or sulphonylureas (< 3 months).
• Untreated stroke etiology: indication for revascularization; non-anticoagulated atrial fibrillation; intracranial atherosclerotic occlusive disease.
• Musculoskeletal or ocular conditions preventing strength training (acute herniated disc, fractures, recent spinal surgery, glaucoma with elevated intraocular pressure).
• Terminal illness.
• Inability to understand basic oral or written Portuguese.
• Participation in supervised dietary intervention.