Alternative research strategies in the exercise - mental health relationship

From the numerous investigations available, there is cautious support for the proposition that exercise is associated with enhanced emotion and mood in mental illness, but the strength of the conclusions derived from the empirical findings available will largely depend on the strength of the designs applied. In applied research, such as the investigation of the exercise - mental health relationship, this relationship depends on population, environmental and individual characteristics and a number of difficulties will certainly hinder progress in this area of inquiry. Randomised controlled trials are important but have the disadvantage of deemphasizing the importance of the individual. Single-case designs on the other hand have considerable potential to adequately unravel the mechanisms at work in the exercise - mental health relationship. From a clinical perspective however, research findings should be viewed based on the support of earlier epidemiological evidence, suggesting that mental illness indeed might be associated with low activity/fitness and that those who maintain activity are less likely to develop mental illness.