Physical Activity and Lifestyle Modifications in the Treatment of Neurodegenerative Diseases to Promote Quality of Life: From Parkinson’s Disease to Dementia

Aim: This narrative review synthesises evidence on physical activity and complementary lifestyle modifications for preventing and managing neurodegenerative disorders, particularly Parkinson's disease, Alzheimer's disease, and related dementias, with attention to quality of life. Methods: A transparent literature search of PubMed, Scopus, Web of Science, and Google Scholar identified peer-reviewed studies published from 2000 to 2025. Randomized controlled trials, cohort and observational studies, systematic reviews, meta-analyses, and clinically relevant mechanistic studies addressing exercise, physical activity, and lifestyle interventions were narratively synthesised. Results: Regular physical activity was associated with improvements in motor performance, gait, balance, muscle strength, cognition, psychological well-being, participation, and quality of life. In Parkinson's disease, aerobic, resistance, balance, dance-based, and task-specific training improved mobility, postural control, functional independence, and non-motor symptoms. In Alzheimer's disease and other dementias, exercise helped maintain cognitive function, daily activities, mobility, social engagement, and caregiver-supported participation. Proposed mechanisms include enhanced neuroplasticity, increased neurotrophic factor expression, improved cerebral perfusion, reduced neuroinflammation, lower oxidative stress, better metabolic regulation, and mitochondrial adaptation. Multicomponent programmes combining aerobic, resistance, balance, and flexibility training appear most consistent, particularly when individualized, supervised, and monitored using perceived exertion or the Talk Test. Diet quality, sleep, stress management, and social engagement may further support healthy ageing and sustained adherence. Conclusion: Physical activity should be integrated as a core adjunct therapy within multidisciplinary neurodegenerative care to support mobility, cognition, independence, and quality of life. Recommendations should be adapted to disease stage, comorbidities, safety risks, caregiver support, preferences, and supervision to improve feasibility and long-term adherence.