Recall-Ability of Moderate and Vigorous Activities Over Lifespan – A Comparison of Data Gathered by Self-Report and Accelerometry

Objective: In order to determine Physical Activity (PA) levels under a health enhancing perspective, Physical activity questionnaires (PAQs) are widely used. Recall ability is a known systematic error in PAQs. The aim of the investigation was to assess the impact of age and type of activity (moderate or vigorous) on the validity of two commonly used self-report PAQs in healthy adults in Germany.

Methods: 198 individuals aged 20-79 years (mean=36,9; sd=15,8), 46% female, BMI 24,3 (sd=3,5) were included in our study. ActiGraph GT3x accelerometers were worn for seven days during all waking periods, except swimming and showering. Immediately after this period participants were ask to recall their activity behavior and fill in the International Physical Activity Questionnaire (IPAQ-long) and a German PAQ (‘Freiburger Fragebogen zur Erfassung körperlicher Aktivität’ (FFkA)).

Results: The results show that both questionnaires overestimate PA behavior in comparison with ActiGraph GT3x. This was the case especially by vigorous activities (IPAQ: 590%; FFkA: 360%) whereas the fit by moderate activities tended to be sufficient (IPAQ: 95%; FFkA: 129%). With increasing age these differences become more distinctive. Total activity levels gathered from both questionnaires were not correlated with each other (r=0,12) and showed only moderate agreement in the Bland-Altman plots.

Discussion: Different studies report on overestimation of self-reported PA behavior. Our results indicate that especially recalling vigorous PA seems to be a major problem in elderly. This could be due to a) an involuntary decrease in recall ability or b) the changing perception of physical strain.