A study recently noted on the blog concerned the objective measurement of exercise using pedometers. Ratings of perceived exertion, on the other hand, have been consistently used as a subjective index of exercise intensity for both exercise testing and prescriptions for exercise. Few empirical efforts have been made to determine how psychological factors influence changes in perceived exercise. A study by Hu and coworkers examined the influence of self-efficacy expectations on changes in ratings of perceived exercise as a function of exercise intensity. The participants were 193 sedentary older adults who completed an assessment of exercise self-efficacy and aerobic capacity. Analyses indicated that ratings of perceived exercise changed as intensity increased and that self-efficacy was a predictor of change. Participants high in self-efficacy maintained a constant rate of change in ratings of perceived exercise as exercise intensity increased, whereas less efficacious participants exhibited a slower rate of change in perceived exercise as a function of exercise intensity, with an initial gradual curve at lower intensity and a more dramatic trajectory at higher intensity.

VALUE OF STUDY TO READER: The results support the importance of ratings for perceived exercise in prescribing exercise for older adults. They also indicate that self-efficacy is implicated in patterns of ratings of perceived exercise change. It would be interesting to repeat this study by using some device, such as pedometers, to provide an objective measure of exercise. The results would be highly valuable.

L Hu et al. Influence of self-efficacy on the functional relationship between ratings of perceived exertion and exercise intensity. Journal of Cardiopulmonary Rehabilitation and Prevention, 2007;27:303-308.