Analysis of 2020 National Health Interview Survey data found a low proportion of U.S. adults met leisure-time aerobic, muscle-strengthening, and combined physical activity guidelines. Residents in larger metropolitan areas and in the West U.S. Census Bureau region were more likely than were those in less populated urban and rural areas or other regions to meet these guidelines.
The healthful effects of physical activity on a multitude of physical and mental health outcomes are well documented (1). Despite promising increases in the percentage of U.S. adults meeting aerobic and muscle-strengthening physical activity guidelines (guidelines)* (1) during leisure time in nearly all demographic and regional subgroups 1998–2018 (2,3), differences by rurality and U.S. Census Bureau region (Northeast, Midwest, South, and West), persist (4). Before 2020, analyses of rural-urban differences were dichotomized into nonmetropolitan (rural) versus metropolitan (urban) areas; however, in 2020 a four-category rural-urban variable† to classify rural-urban status was included in the National Health Interview Survey (NHIS) public-use dataset. NHIS 2020 data were used to conduct multivariate logistic regression analyses by rural-urban status and U.S. Census Bureau region of the prevalence of meeting the aerobic, muscle-strengthening, and combined aerobic and muscle-strengthening guidelines during leisure time among adults aged ≥18 years, controlling for demographic characteristics. Prevalence of meeting the aerobic, muscle-strengthening, and combined aerobic and muscle-strengthening guidelines was consistently the lowest in Nonmetropolitan counties (38.2%, 21.1%, and 16.1%, respectively) and highest in the West region (52.1%, 35.3%, and 28.5%, respectively). Regardless of rural-urban classification and region, no more than 28% of adults met combined aerobic and muscle-strengthening guidelines. Adults in the most rural category were significantly less likely to meet aerobic, muscle-strengthening, and combined guidelines than were adults in each of the three other categories (adjusted odds ratio [aOR] range = 0.68–0.89). In addition, adults in medium and small metropolitan counties were less likely to meet guidelines than were adults in the two most urban categories (aOR range = 0.85–0.89). Adults in the Northeast, Midwest, and South U.S. Census Bureau regions were less likely to meet guidelines than were adults in the West region (aOR range = 0.75–0.82). These analyses identify geographic disparities in leisure-time physical activity where focused population-level intervention efforts could help reduce or eliminate the consequent disparities in chronic conditions (e.g., cardiovascular diseases) and the resulting mortality (5,6).
NHIS is a nationally representative sample of noninstitutionalized U.S. adults that includes annual multistage cross-sectional household surveys conducted by CDC.§ NHIS 2020 public-use data were analyzed, because changes in the NHIS questionnaire precluded analysis of trend data or combining administration years. NHIS 2020 is also the first year that the NHIS public-use dataset included the four-category rural-urban county classification variable in public-use data. The 2020 sample of 31,568 adults included 21,153 (67%) participants interviewed for the 2020 annual administration and 10,415 (33%) from the 2019 sample who were reinterviewed for longitudinal analyses. Response rates for the 2020 sample were 48.9% (interviewed) and 29.6% (reinterviewed).¶ Among adults in the 2020 sample, information on the indicators of interest was missing for 1,161 (4%) respondents, resulting in a final analytic sample of 30,407.
Three dependent variables were analyzed. First, respondents were classified as either meeting or not meeting the aerobic guideline of ≥150 minutes per week based on self-reported frequency and duration of moderate and vigorous intensity leisure-time aerobic activity.** Second, respondents were classified as either meeting or not meeting the muscle-strengthening guideline of ≥2 days per week based on self-reported frequency of muscle-strengthening activities.†† Finally, respondents were classified as meeting the combined guideline if they met both the aerobic and muscle-strengthening guidelines.
Multivariable logistic regression analyses were conducted to model unadjusted and adjusted predicted population probabilities of dependent variables by rural-urban classification (nonmetropolitan [micropolitan and noncore], medium and small metropolitan, large fringe metropolitan, and large central metropolitan [referent]) and U.S. Census Bureau region (Northeast, Midwest, South, and West [referent]),§§ while controlling for biologic sex, age, race and ethnicity, education, and income-to-poverty threshold.¶¶ In addition, least-squares mean estimates were used to calculate the predicted population margin effects to compare within categories of the primary predictors (rurality and region). All analyses were performed using SAS (version 9.4; SAS Institute) with parameters adjusted for population weights, clusters, and stratification following NHIS analytic guidelines. These analyses were not subject to Institutional Review Board approval because deidentified public-use data were analyzed. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.***
Prevalence rates are 31.9%-72.3% higher in the most active counties by rural-urban classification and 20.3%-29.5% higher in the West than in the South U.S. Census Bureau region (Table 1). The lowest prevalence of meeting the aerobic, muscle-strengthening, and combined guidelines was observed among adults living in the most rural counties (nonmetropolitan; 38.2%, 21.1%, and 16.1%, respectively) and in the South U.S. Census Bureau region (43.3%, 29.0%, and 22.0%, respectively). Residents of medium and small metropolitan counties and nonmetropolitan counties were significantly less likely to meet aerobic, muscle-strengthening, and combined guidelines than were residents of large central metropolitan counties (aOR = 0.68–0.89). Compared with residents of the West U.S. Census Bureau region, those in all other U.S. Census Bureau regions were significantly less likely to meet aerobic, muscle-strengthening, and combined guidelines (aOR range = 0.75–0.82).
In addition, least-squares mean estimates indicate that residents of nonmetropolitan counties were less likely to meet aerobic, muscle-strengthening, and combined guidelines than were residents of medium and small metropolitan counties (aOR range = 0.78–0.89) and large fringe metropolitan counties (aOR range = 0.72–0.78) (Table 2). Residents of medium and small metropolitan counties were less likely than were residents of large fringe metropolitan counties to meet aerobic (aOR = 0.88) and combined guidelines (aOR = 0.86). Residents in the Northeast, Midwest, and South regions did not differ from one another in likelihood of meeting guidelines (aOR range = 0.99–1.07).