Matthews CE, et al. - In this study, researchers evaluated the utility of measurement methods that may be more accurate and precise than traditional questionnaire-based estimates of habitual physical activity and sedentary behavior that compared the measurement properties of a past year questionnaire (AARP) and more comprehensive measures: an internet-based 24-hour recall (ACT24), and a variety of estimates from an accelerometer (ActiGraph). New exposure assessments suitable for use in large epidemiologic studies (ACT24, ActiGraph) were more accurate and had higher correlations than a traditional questionnaire. Utilization of better more comprehensive measures in future epidemiologic studies could yield new etiologic discoveries and possibly new opportunities for prevention.