 The International Physical Activity Questionnaire, short form, IPA-QSF, has been recommended as a cost-effective method to assess physical activity, but several studies validating it have shown differing results. A systematic review was conducted to analyze these studies and found that the correlation between the IPA-QSF and objective measures of activity or fitness in most studies was lower than the acceptable standard. Additionally, the IPA-QSF typically overestimated physical activity as measured by objective criterion by an average of 84%. Therefore, the evidence to support the use of the IPA-QSF as an indicator of relative or absolute physical activity is weak. This article was authored by Stuart Sunita M, Lanth, McFarlane Duncan J, and others.