A number of studies demonstrate the positive benefits of exercise for people with schizophrenia and schizoaffective disorders; however the exercise program variables resulting in these positive effects have not been evaluated. Therefore the aim of this systematic review was to describe the aerobic exercise program variables used in randomized controlled trials reporting the positive effect of exercise in the treatment of schizophrenia or schizoaffective disorder. Studies were analyzed for exercise frequency, intensity, session duration, exercise type, intervention duration, delivery of exercise, and level and quality of supervision and adherence. Study quality was assessed using the Physiotherapy Evidence Database scale. Three studies met the inclusion criteria. In general, exercise intervention variables are reported poorly. We find that aerobic exercise including treadmill walking and cycle exercise undertaken as a supervised group intervention lasting 30 to 40 min per session and undertaken 3 times weekly at moderate intensity appears to be valuable for people with schizophrenia or schizoaffective disorder. Interventions ranged from 10 to 16 wk. No adverse events were reported in the included studies. Evidence suggests that aerobic exercise is safe and beneficial for people with schizophrenia or schizoaffective disorder.