Principal Investigator left the institution

Previous studies have shown that cardiorespiratory fitness (how well the heart and lungs are able to function during physical activity) is often reduced in people with psychosis. The goal of this research study is to test the hypothesis that aerobic exercise can lead to small changes in brain functioning that can influence visual perception and attention in psychosis. The type of aerobic exercise used in this study is called Sprint Interval Training, or "SIT". Information from this study will help to develop interventions that enhance cognition and maximize the quality of life for persons living with psychosis.

The exercise procedure used is called SIT, which involves training rigorously on a stationary bike for a short period of time followed by a resting period.

Inclusion Criteria:

• Meet diagnostic criteria for schizophrenia or schizoaffective disorder
• Are age 18-64
• Fluent in written and spoken English
• Have an outpatient status of at least 1 month prior to participation
• Has been on a stable dose of psychiatric medication for at least one month prior to participation (titration to a lower dose of psychotropic medications under supervision of a psychiatrist can be allowed at the discretion of the investigators)

Exclusion Criteria:

• Current or possibility of current pregnancy (self-reported)
• Active suicidal ideation at screening or baseline assessments, or previous intent to act on suicidal ideation with a specific plan, preparatory acts, or an actual suicide attempt within the last 3 months, as indicated by the C-SSRS
• WTAR standardized score below 70
• American College of Sports Medicine contraindication to exercise

Individuals in good health with a psychotic disorder.