This observational study aims to evaluate exercise capacity, pulmonary function, respiratory muscle strength, and quality of life in individuals diagnosed with schizophrenia and bipolar disorder. These psychiatric conditions are associated with sedentary lifestyles, metabolic side effects of psychotropic medications, and increased comorbidity risks, all of which may negatively impact physical fitness and respiratory health. By assessing cardiorespiratory endurance, pulmonary parameters (FVC, FEV₁), and respiratory muscle strength in this population, the study seeks to identify physiological limitations and contribute to the development of more effective rehabilitation strategies. The findings may support multidisciplinary approaches to improving physical health and overall quality of life in individuals with severe mental illness.