Sedentary Behavior in United States Adults: Fall 2019.

PURPOSE Higher levels of sedentary behavior are associated with early mortality, but the distribution of sedentary time by classes of behavior and demographic groups is poorly described in United States (US) adults. To quantify the amount and sources of sedentary time in US adults we conducted a nationwide survey using a novel validated self-administerd previous-day recall method and compare these values with a commonly used sitting time question. METHODS Participants from the AmeriSpeak panel aged 20 to 75 years (N = 2,640) completed up to two Activities Completed over Time in 24 Hours (ACT24) previous day recalls. Recalls were conducted on randomly selected days in October and November 2019. Survey sample design were applied to reflect the US population. RESULTS Mean age was 45.3 years, 51% were female, 67% non-Hispanic white, and 37% had a body mass index of ≥30 kg/m2. US adults reported a mean 9.5 hrs/d of sedentary time (95% confidence interval [CI] 9.4, 9.7 hrs/d), which was 34% more than reported using a common surveillance measure (p < 0.01). Most daily sedentary time was accumulated in the leisure and work life domains, with leisure accounting for 47% (4.3 hrs/d [95%CI 4.2, 4.5 hrs/d]) of the total sedentary time. Eighty-two percent of leisure time was spent sedentary, mainly watching television/videos or engaged in internet/computer use. CONCLUSIONS US adults appear to spend more time in sedentary behavior than previously thought and the majority of this time is accumulated at work and in leisure-time. Reducing sedentary screen-time during leisure in favor of physically active could be an important intervention target in the effort to increase physical activity in US adults.