Effects of high-intensity aerobic exercise on psychotic symptoms and neurocognition in outpatients with schizophrenia: study protocol for a randomized controlled trial

BACKGROUND: The focus in recent years on physical inactivity and metabolic disturbances in individuals with schizophrenia raises the question of potential effects of physical activity. Physical activity has shown beneficial effects on cognition in healthy older individuals as well as on symptom severity in depression. However, opinions diverge regarding whether aerobic high-intensity interval training reduces cognition and key symptoms in schizophrenia. The main objective for the trial is to investigate the potential effects of aerobic high-intensity interval training on neurocognitive function and mental symptoms in outpatients with schizophrenia. METHODS/DESIGN: The trial is designed as a randomized controlled, observer-blinded clinical trial. Patients are randomized to 1 of 2 treatment arms with 12-week duration: aerobic high-intensity interval training or computer gaming skills training. All participants also receive treatment as usual. Primary outcome measure is neurocognitive function. Secondary outcome measures will be positive and negative symptoms, wellbeing, tobacco-smoking patterns and physiological/metabolic parameters. Patient recruitment takes place in catchment area-based outpatient clinics. TRIAL REGISTRATION: ClinicalTrials.gov NCT02205684. Registered 29 July 2014.