Long-term physical activity intensity and all-cause and cause-specific mortality in 25 high-income, middle-income, and low-income countries

Background Few studies have investigated the independent association of physical activity (PA) at different intensities (walking, moderate PA [MPA], and vigorous PA [VPA]) with mortality. Prior evidence was primarily from high-income countries and used single measures of recreational PA as the exposure of interest. Purpose To investigate the association of long-term PA intensity with mortality in 25 countries at different economic levels in the Prospective Urban Rural Epidemiology study. Methods This population-based cohort study included 142,949 participants aged 35-70 years recruited from January 1, 2003, and followed up until August 5, 2025. Self-reported PA was assessed using the International Physical Activity Questionnaire every three years. The primary exposures were long-term walking, MPA, and VPA captured by the cumulative average of repeated measures. The long-term proportion of VPA to total PA (%VPA) was analyzed as a secondary exposure. The associations of PA intensity with all-cause and cause-specific mortality were assessed using time-varying Cox frailty models. Results Of 142,949 participants, 84,652 (59.2%) were women, and the mean age was 50.1 ± 9.6 years. The median levels of long-term walking, MPA, and VPA were 210 (88–420), 210 (80–470), and 150 (0–435) min/wk, respectively. During a median follow-up of 15.0 (IQR, 12.3-16.5) years, 16,105 participants died (5,233 from cardiovascular disease). Increasing amounts of walking, MPA, and VPA were inversely associated with all-cause, cardiovascular, and non-cardiovascular mortality. Lower mortality risks began at very low volumes (HR for 1-74 minutes/week: 0.92 [95% CI, 0.85-0.99] for walking; 0.85 [0.80-0.91] for MPA; 0.88 [0.83-0.94] for VPA), and the association strengthened at higher levels and did not show any harm at levels even up to ≥1800 minutes per week (HR for ≥1800 minutes/week: 0.90 [0.77-1.06] for walking; 0.77 [0.69-0.85] for MPA; 0.63 [0.50-0.79] for VPA). When total PA was kept constant, a higher proportion of VPA was associated with lower mortality risk. Compared with those with no VPA, engaging >0-25%, >25-50%, >50-75%, and >75-100% VPA was associated with an HR of 0.84 (0.79-0.89), 0.79 (0.74-0.84), 0.76 (0.72-0.81), and 0.79 (0.72-0.86) for all-cause mortality; similar patterns were observed for non-CVD mortality (Figure). Conclusion The protective association of intensity-specific PA with all-cause mortality begins at very low levels and persists across a wide range, even at extremely high levels, and higher PA intensity was also associated with greater mortality reduction.