Objective: To evaluate the influence of expectations on effectiveness of exercise in reducing psychological distress.
Method: Data came from a Swedish longitudinal population-based study consisting of 4631 people aged 20-64 years. Psychological distress was measured with the Major Depressive Inventory. Expectations (positive expectations or indifference) towards exercise were combined with exercise (regular exercise: yes or no).
Results: Indifferent non-exercisers had increased risk of psychological distress. Regular exercisers who were indifferent towards exercise as a self-help method were less likely to be psychologically distressed compared to exercisers with positive expectations.
Conclusion: The results encourage systematic use of exercise in prevention and rehabilitation of persons suffering from psychological distress. People's personal expectations might not be needed for treatment effect.