Abstract
This study uses National Health and Nutrition Examination Survey data to examine changes in sedentary time among adults in the US from 2013 to 2023.
Sedentary behavior has become increasingly prevalent in modern society, and a previous report documented a notable increase in sedentary time among US adults in 2007 to 2016. In 2018, the second edition of Physical Activity Guidelines for Americans recommended, for the first time, reducing sedentary behavior as a key strategy for preventing chronic diseases. However, little is known about how the pattern of sedentary behavior has shifted in recent years, particularly following the COVID-19 pandemic, during which sedentary lifestyle may even become more pervasive. This study analyzed national survey data to estimate the changes in sedentary time among US adults in 2013 to 2023.
Methods
The National Health and Nutrition Examination Survey is a nationally representative survey of non-institutionalized US civilians. The protocols were approved by the National Center for Health Statistics, and written informed consent was obtained from participants. This study included cycles between 2013 and August 2023. Field operations were suspended in March 2020 due to the COVID-19 pandemic; data collected during 2019 through March 2020 were combined with data from the 2017-2018 cycle to form a nationally representative sample of 2017 to March 2020 prepandemic data. We included 28 145 adults 20 years or older with available and plausible information on self-reported sedentary time (≤16 hours/d).
For sedentary behavior, participants were asked how much time in a typical day they spent “sitting at school, at home, getting to and from places, or with friends including time spent sitting at a desk, traveling in a car or bus, reading, playing cards, watching television, or using a computer.” This question has been validated in the US adult sample with reasonable repeatability (criterion validity Spearman ρ >.45; test-retest Spearman ρ >.71). Self-reported race and ethnicity were derived from responses to fixed categories and assessed due to racial disparities in sedentary behaviors.
Because sedentary time was normally distributed, we presented the age- and sex-standardized mean levels and 95% CIs overall and across age, sex, and race and ethnicity subgroups. To assess the prevalence of prolonged sedentary behavior, we dichotomized the sedentary time using 6 hours per day, above which has been associated with cardiovascular disease and mortality in prior studies. Changes across surveys were estimated using multivariable linear regression adjusted for the survey cycle, age, sex, and race and ethnicity. Linear and quadratic trends were assessed using polynomial regression accounting for unequal survey cycle spacing. Sample weights were used to adjust for non-response, non-coverage, and unequal probability of selection. Analyses accounted for the complex survey design and were conducted using SAS version 9.4 (SAS Institute). All statistical tests were 2-sided, with a significance threshold of P < .05. We followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.
Results
The weighted mean (SD) age of participants was 48.1 (0.25) years, and 51.7% were women. The mean sedentary time significantly decreased from 7.1 (95% CI, 6.9-7.3) hours per day in 2013-2014 to 5.9 (95% CI, 5.8-6.0) hours per day in 2017-2020. After that, mean sedentary time did not further decline, with 6.0 (95% CI, 5.8-6.2) hours per day in 2021-2023 (P < .001 for both linear and quadratic trends; Table). In 2013-2014, the weighted prevalence of prolonged sedentary behavior (≥6 hours/d) was 54.6% (95% CI, 52.0%-57.1%). The prevalence decreased to 35.5% (95% CI, 33.6%-37.5%) in 2017-2020 and remained similar in 2021-2023 (36.7% [95% CI, 34.3%-39.0%]; Figure). The patterns were similar across age, sex, and race and ethnicity subgroups, but older (age ≥65 y) and Hispanic participants had a lower prevalence of prolonged sedentary behavior.
Table. Trends in Mean Hours per Day of Sedentary Behavior Among US Adultsa.
| Sedentary time per day, mean (SD), h | Difference, h/d | P value for trendb | P value for interactionc | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 2013-2014 (n = 5717) | 2015-2016 (n = 5635) | 2017-2020 (n = 9117)d | 2021-2023 (n = 7676) | 2017-2020 vs 2013-2014 | 2021-2023 vs 2017-2020 | Linear | Quadratic | ||
| Overall (n = 28145) | 7.1 (6.9 to 7.3) | 6.5 (6.3 to 6.7) | 5.9 (5.8 to 6.0) | 6.0 (5.8 to 6.2) | −1.2 (−1.4 to −1.0) | 0.1 (−0.1 to 0.4) | <.001 | <.001 | |
| Sex | .53 | ||||||||
| Men (n = 13312) | 7.1 (6.9 to 7.4) | 6.5 (6.3 to 6.8) | 6.0 (5.8 to 6.1) | 6.1 (5.8 to 6.3) | −1.2 (−1.4 to −0.9) | 0.1 (−0.2 to 0.4) | <.001 | <.001 | |
| Women (n = 14833) | 7.0 (6.9 to 7.2) | 6.5 (6.3 to 6.7) | 5.8 (5.7 to 6.0) | 5.9 (5.8 to 6.1) | −1.2 (−1.5 to −1.0) | 0.1 (−0.1 to 0.3) | <.001 | <.001 | |
| Age, y | .77 | ||||||||
| 20-44 (n = 11019) | 7.1 (6.9 to 7.3) | 6.5 (6.3 to 6.7) | 5.9 (5.7 to 6.0) | 6.0 (5.8 to 6.2) | −1.1 (−1.4 to −0.7) | 0.2 (−0.1 to 0.6) | <.001 | <.001 | |
| 45-64 (n = 9587) | 6.9 (6.6 to 7.1) | 6.4 (6.2 to 6.6) | 5.8 (5.6 to 6.1) | 6.1 (5.8 to 6.3) | −1.4 (−1.7 to −1.0) | 0.1 (−0.3 to 0.4) | <.001 | <.001 | |
| ≥65 (n = 7539) | 7.3 (7.1 to 7.5) | 6.7 (6.4 to 6.9) | 5.9 (5.7 to 6.2) | 6.0 (5.7 to 6.3) | −1.2 (−1.5 to −0.9) | −0.1 (−0.4 to 0.1) | <.001 | <.001 | |
| Race and ethnicity | .54 | ||||||||
| Hispanic (n = 6281) | 5.9 (5.6 to 6.2) | 5.2 (5.0 to 5.5) | 4.6 (4.3 to 4.9) | 4.9 (4.6 to 5.1) | −1.3 (−1.8 to −0.9) | 0.3 (−0.1 to 0.6) | <.001 | <.001 | |
| Non-Hispanic Asian (n = 2878) | 7.0 (6.7 to 7.3) | 6.4 (6.1 to 6.6) | 5.5 (5.3 to 5.7) | 5.8 (5.4 to 6.1) | −1.5 (−1.8 to −1.1) | 0.3 (−0.2 to 0.7) | <.001 | <.001 | |
| Non-Hispanic Black (n = 5721) | 7.4 (7.1 to 7.8) | 6.2 (5.9 to 6.5) | 5.6 (5.4 to 5.8) | 5.9 (5.5 to 6.2) | −1.8 (−2.2 to −1.5) | 0.3 (−0.1 to 0.7) | <.001 | <.001 | |
| Non-Hispanic White (n = 11959) | 7.2 (7.1 to 7.4) | 6.9 (6.6 to 7.1) | 6.3 (6.1 to 6.5) | 6.3 (6.1 to 6.6) | −1.0 (−1.2 to −0.7) | 0.1 (−0.3 to 0.4) | <.001 | .004 | |
| Non-Hispanic other (n = 1306)e | 7.0 (6.5 to 7.4) | 5.8 (5.4 to 6.3) | 6.0 (5.5 to 6.6) | 5.8 (5.5 to 6.2) | −0.9 (−1.7 to −0.2) | −0.2 (−0.9 to 0.5) | .09 | .20 | |
Values were standardized by age and sex to the 2010 US Census population.
Calculated using polynomial regression models accounting for unequal survey cycle spacing.
Estimated using multivariable linear regression with indicator variables for the survey cycle, age, sex, and race and ethnicity.
Data collected from 2019 to March 2020 were combined with data from the 2017-2018 cycle to form a nationally representative sample of National Health and Nutrition Examination Survey 2017-March 2020 prepandemic data.
Non-Hispanic other included those who self-reported multiracial or any non-Hispanic race other than Asian, Black, or White.
Figure. Trends in Prolonged Sedentary Behavior Among US Adults, 2013-2014 to August 2021-August 2023.
Error bars indicate 95% CIs. Prolonged sedentary behavior was defined as ≥6 hours/d as prior study suggesting over 6 hours of sitting time was associated with higher risks of cardiovascular disease and mortality. Values were standardized by age and sex to the 2010 US Census population. Non-Hispanic other included those who self-reported multiracial or any non-Hispanic race other than Asian, Black, or White. Data collected from 2019 to March 2020 were combined with data from the 2017-2018 cycle to form a nationally representative sample of National Health and Nutrition Examination Survey 2017-March 2020 prepandemic data.
Discussion
This study identified a promising trend of declining sedentary behavior among US adults between 2013 and March 2020, but this decline was hampered in 2021-2023. Sedentary lifestyle was widely exacerbated during the COVID-19 pandemic, and this study highlights the enduring impact that this global pandemic may have on daily living patterns.
Study limitations include self-reported sedentary time, but measurement errors were unlikely to affect findings on the secular trends over time. Additionally, the response rate during the 2021-2023 survey cycle was low (25.6%), although weighting adjustment methods applied to this cycle addressed potential nonresponse bias.
Data sharing statement
References
- 1.Yang L, Cao C, Kantor ED, et al. Trends in sedentary behavior among the US population, 2001-2016. JAMA. 2019;321(16):1587-1597. doi: 10.1001/jama.2019.3636 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Piercy KL, Troiano RP, Ballard RM, et al. The physical activity guidelines for Americans. JAMA. 2018;320(19):2020-2028. doi: 10.1001/jama.2018.14854 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Hall G, Laddu DR, Phillips SA, Lavie CJ, Arena R. A tale of two pandemics: how will COVID-19 and global trends in physical inactivity and sedentary behavior affect one another? Prog Cardiovasc Dis. 2021;64:108-110. doi: 10.1016/j.pcad.2020.04.005 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Craig CL, Marshall AL, Sjöström M, et al. International physical activity questionnaire: 12-country reliability and validity. Med Sci Sports Exerc. 2003;35(8):1381-1395. doi: 10.1249/01.MSS.0000078924.61453.FB [DOI] [PubMed] [Google Scholar]
- 5.Li S, Lear SA, Rangarajan S, et al. Association of sitting time with mortality and cardiovascular events in high-income, middle-income, and low-income countries. JAMA Cardiol. 2022;7(8):796-807. doi: 10.1001/jamacardio.2022.1581 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Stockwell S, Trott M, Tully M, et al. Changes in physical activity and sedentary behaviours from before to during the COVID-19 pandemic lockdown: a systematic review. BMJ Open Sport Exerc Med. 2021;7(1):e000960. doi: 10.1136/bmjsem-2020-000960 [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data sharing statement
