Physical Activity Guideline Adherence and High-Impact Chronic Pain Among U.S. Adults: A Cross-Sectional Analysis of the 2020 National Health Interview Survey

PREPRINT: Abstract: Purpose: To examine the dose–response relationship between physical activity (PA) guideline adherence and high-impact chronic pain (HICP) prevalence among U.S. adults. Design: Cross-sectional secondary analysis. Setting: 2020 National Health Interview Survey (NHIS), the only publicly available NHIS year containing both HICP assessment items and detailed PA measures in the same adult sample. Sample: 27,068 adults aged ≥18 years with complete data on PA, HICP, and covariates, representing approximately 215 million non-institutionalized U.S. adults. Measures: HICP was defined per NHIS criteria as chronic pain frequently limiting life or work activities. PA was categorized as no PA, some PA below guidelines, meets aerobic only, and meets both aerobic and muscle-strengthening guidelines. Analysis: Survey-weighted linear probability models estimated adjusted HICP prevalence by PA category. A Wald trend test assessed monotonic association. Modified Poisson regression estimated prevalence ratios (PR) and, with natural cubic splines, modeled continuous dose–response. All models adjusted for age, sex, and race/ethnicity. Sensitivity analyses examined expanded covariates, exclusion of respondents unable to exercise, and subgroup interactions (Supplement 2). Results: Adjusted HICP prevalence decreased from 8.4% (no PA) to 3.9% (some PA), 2.9% (aerobic only), and 2.9% (both guidelines) (trend p < .001). Corresponding prevalence ratios were 0.45, 0.33, and 0.26 relative to no PA. Continuous modeling revealed steep HICP reductions at low activity volumes, plateauing beyond approximately 200–300 minutes/week. Results were robust to exclusion of respondents coded as unable to exercise and persisted, though attenuated, after greater adjustments for education, BMI, arthritis, depression, anxiety, and income. Conclusion: Higher PA levels were associated with progressively lower HICP prevalence, with the greatest reductions occurring at the transition from inactivity to any PA. Keywords: physical activity, chronic pain, national health interview survey, dose-response, health promotion