The vagaries of self-reports of physical activity: A problem revisited and addressed in a study of exercise promotion in the over 65s in general practice

Background. The assessment of levels of physical activity relies upon suitable measurement tools. Objective. We aimed to investigate whether a practice nurse, using a motivational interview technique, could encourage older patients to increase their physical activity. Methods. Health and well-being were monitored at baseline and 8 weeks following intervention. Physical activity levels were ascertained using both a self-report measure and ambulatory heart-rate monitoring. Results. Whilst patients reported higher levels of physical activity at follow-up, this finding was not confirmed by the heart-rate data. Conclusion. The study concludes that patients tend to overestimate the amount of physical activity undertaken and that ambulatory heart-rate monitoring may be more useful for verifying actual behaviour.