Agreement on "being sufficiently active for health" measured objectively by pedometer and subjectively by IPAQ questionnaires

Background: Measuring physical activity is complex and to achieve reliable and accurate measurements is challenging. Physical activity can be assessed subjectively using a variety of self report questionnaires, diaries, or logs or objectively using devices such as pedometers and accelerometers. This study aimed to test agreement on "being sufficiently active for health" measured objectively by pedometer and subjectively by International Physical Activity Questionnaires. Methods: Local government workers wore a Yamax Digi-walker pedometer for a one week period after which time they completed the Long Version of the International Physical Activity Questionnaire to allow a comparison between objective and subjective measures of physical activity. Results: Analysis of pedometer data showed that 49% of participants were sufficiently active for health (10,000 steps in a 24 hours period was used to define "sufficiently active for health). IPAQ classification of physical activity revealed much higher perceived levels of physical activity with 18.9% classified as achieving medium levels of activity and 73% achieving high levels of activity. Conclusions: In this study pedometers were shown to be more accurate measurements of physical activity with the self-report survey vastly over-estimating the actual physical activity achieved. Use of subjective measures of physical activity may under-estimate the true picture of physical activity behaviour in populations and wherever possible more objective measures should be used.