Agreement between participant-rated and compendium-coded intensity of daily activities in a triethnic sample of women ages 40 years and older

Participant-rated and compendium-coded intensity of daily physical activities were compared in 148 African American, 144 Native American, 51 non-Hispanic White women ages 40 to 91 years who completed 4 days of activity records. For compendium-coded intensity, reported activities were classified as light (< 3 metabolic equivalents [METS]), moderate (3-6 METS), or vigorous (> 6 METS) using the Compendium of Physical Activities (1), whereas these categories were self-assigned for participant-rated intensity. Minutes per day (min/d) spent in activities at each intensity level were computed. Relative to compendium-coded min/d, participants reported significantly greater time spent in light (+10 min/d; p <. 01) and vigorous (+17 min/d; p <. 001) activities, and less time spent in moderate activities (-27 min/d; p <. 001). Similarly, compendium-coded estimates yielded higher rates of participants meeting Centers for Disease Control and Prevention - American College of Sports Medicine and Surgeon General recommendations than participant-rated estimates (11-18% differences) but substantially lower rates meeting American College of Sports Medicine vigorous recommendations (22% difference). Further, 247 greater kilocalories per day were estimated based on compendium-coded intensity. Kilocalories per day estimates based on compendium codings were more highly associated with pedometer counts than those based on participant ratings (p <. 05). Study patterns were generally seen across all sample subgroups. Discrepancies between participant and compendium estimates are likely to be most meaningful in studies estimating energy expenditure as it relates to health outcomes and in studies estimating vigorous activities.