Background: The survival benefits associated with meeting physical activity (PA) and muscle strengthening (MS) guidelines are well established. Data examining the independent association of PA with all-cause mortality, specifically among MS-compliant adults, are sparse. Purpose: The primary purpose of this study was to examine the association that PA status has on all-cause mortality among adults meeting MS guidelines. The secondary purpose was to examine the joint influence of PA and disease status on all-cause mortality. Methods: A baseline sample of 116,512 adults from the 1997 to 2018 National Health Interview Survey (NHIS) was used with the National Center for Health Statistics (NCHS) 2019 public-use linked mortality files. Meeting PA guidelines was defined as engaging in 150+ min/week of moderate-to-vigorous aerobic PA (MVPA) during leisure time. The sample was limited to adults 18+ years of age meeting MS guidelines (i.e., MS 2+ days/week). Demographic variables included age, sex, race, and income. Health indicators included BMI categories, smoking status, and number of diseases. Cox proportional hazards regression was used to estimate hazard ratio (HR) statistics associated with all-cause mortality and their 95% confidence intervals (CIs). Poisson regression with robust error variance was used to estimate similar relative risk (RR) statistics. Results: During a median follow-up period of 10.2 (95% CI: 10.10–10.24) years, 8,589 (7.4%) deaths were observed. Approximately 83.5% (95% CI: 83.12-83.77) of MS-compliant adults met PA guidelines at baseline. Among those that survived and died, 84.7% (95% CI: 84.40–85.03) and 63.5% (95% CI: 62.18–64.74) met PA guidelines at baseline, respectively. In the fully adjusted hazards model, those not meeting PA guidelines saw 59% (HR = 1.58, 95% CI: 1.49–1.67) greater risk of mortality as compared to their PA-compliant counterparts. In the eight-group joint PA and disease status model, those not meeting PA guidelines with 3+, 2, 1, and 0 diseases and those meeting PA guidelines with 3+, 2, 1, and 0 (reference) diseases saw a significant (p < .0001) linear trend in mortality risk decreasing from HR = 5.27 (95% CI: 4.66–5.95) to HR = 1.70 (95% CI: 1.56–1.85), respectively. A separate analysis of disease-free adults showed a 51% (HR = 1.51, 95% CI: 1.38-1.66) greater risk of mortality in those not meeting PA guidelines. Poisson models with RR statistics saw similar risk statistics and similar linear trend. Conclusion: A considerable mortality risk was observed among adults not meeting aerobic PA guidelines, despite meeting MS guidelines. The mortality risk was seen in disease-free adults, however, the risk grew in magnitude as the number of diseases increased. Engaging in recommended amounts of aerobic PA could add survival benefit even among strength-trained populations.

Physical activity, Muscle strengthening, Mortality, Population health