Neuronal Effects of Exercise in Schizophrenia

This study is investigating whether regular aerobic exercise changes how the brain works in people with schizophrenia, using brain scans to measure the effects on brain structure and function. **You may be eligible if...** - You are between 21 and 70 years old - You have been diagnosed with schizophrenia or schizoaffective disorder - You are currently taking olanzapine, risperidone, clozapine, or haloperidol — OR you are not currently taking any antipsychotic medication - Your weight has been stable (within 5%) for the past 6 months **You may NOT be eligible if...** - You are pregnant - You have a substance abuse problem - You have significant uncontrolled medical conditions such as severe high blood pressure or very high blood fat levels - You have conditions that prevent you from safely having an MRI (such as claustrophobia or metal implants in your body) Talk to your doctor to see if this trial is right for you.