Physical health problems are common in schizophrenia with a two- to three-fold increased morbidity and mortality rate, resulting in a 20 years reduction in life expectancy. A genetic vulnerability for developing cardiovascular disease has been documented in these patients, and many lifestyle factors also negatively influence physical health. Patients with schizophrenia are likely to smoke, are physically inactive and overweight, suffer from malnutrition due to unhealthy diet, and have reduced cardiorespiratory fitness. Moreover, these patients have increased risk of developing diabetes mellitus type II and metabolic syndrome. These aspects demonstrate the need for multi-disciplinary treatments of patients with schizophrenia and underline the need for addressing their physical health.

Poor physical fitness seems to be associated with exacerbated negative symptoms and increased cognitive dysfunction in patients with schizophrenia. However, evidence on physical activity and its consequences in schizophrenia is scarce. In this randomized controlled trial we investigate the effects of high intensity training in outpatients with schizophrenia on psychotic symptoms and well-being, cognition and cortical structure, tobacco smoking and substance use, in addition to metabolic indices.

Outpatients in treatment will be recruited in this randomized controlled trial (RCT). The patients will be randomized to either a Computer gaming Skills Group (CSG) or to a physical Exercise Group (EG). The groups are identically organized in two locations. The interventions last for 12 weeks, and treatment as usual will be continued for all patients. Patients will be assessed when entering the study (after randomization and allocation to one of the clinical groups), as well as post-treatment and 4 months post-treatment. Thus, the planned study is prospective with a longitudinal design. It is single blind in the sense that the assessment of psychiatric symptom level and neurocognitive function will be performed by research staff blind for group membership. The physiological testing will be performed by staff involved in training and will not be blinded.

EG participants will perform aerobic high intensity training (HIT) consisting of supervised walking/running on a treadmill 2 times a week for 12 weeks. Each session will have the following structure; eight-minute warm-up, followed by four times four minutes intervals with 85-95% of maximum heart rate, with active pauses of three minutes of walking at 70% of maximum heart rate. The exercise session will end with a five minute cool-down period. HIT performed as 4 x 4 intervals has been proven feasible and safe among patients with schizophrenia and in other clinical populations.

Participants in the CSG take part in sessions in the clinic playing computer games (Nintendo Wii Sports). The time spent with activities in the clinic will be the same in both groups. When absent from scheduled physical exercise/playing computer games the subjects will be offered to participate on a following day. If absent for a whole week, the training period/computer games playing period will be prolonged accordingly.

In this randomized controlled trial we investigate the effects of HIT in outpatients with schizophrenia on symptoms and well-being, cognition and brain structure, smoking habits and substance use, as well as metabolic indices.

The participating outpatient clinics are catchment area based and cover a population of 200 000 persons with more than 250 patients in the diagnostic group in treatment at one time.

Inclusion Criteria:

• verified (Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, SCID) diagnosis of schizophrenia spectrum disorder
• outpatient in treatment
• written informed consent
• fluent in a Scandinavian language

Exclusion Criteria:

• chest pain during exercise
• unstable angina pectoris
• suspicion of recent myocardial infarction
• uncontrollable arrhythmia
• acute infection with lymphadenopathy
• malignant hypertension
• neurological disorder
• severe physical disability
• medical condition incompatible with particiption
• comorbid diagnosis of mild mental retardation
• pregnancy