Psychological changes during a controlled trial of rehabilitation in chronic respiratory disability

Thirty-four men with chronic respiratory disability took part in a randomised, controlled trial of physical training. The control group also undertook exercise training after their control period. During the study measurements were made of exercise tolerance (12-minute walking distance) and the men completed two psychology questionnaires. Walking distance improved significantly more in the treatment group than in the control group. Both groups recorded scores suggesting psychological "improvement" and the changes in the two groups were not significantly different from each other. There were no consistent associations between the increase in walking distance and changes in psychological scores. Initial psychological scores were not useful in predicting changes in walking distance. The results suggest that the effect of treatment on walking distance was not psychological.