Physical activity volume, intensity, and mortality: Harmonized meta-analysis of prospective cohort studies

Introduction It is unclear whether moderate-to-vigorous physical activity (MVPA) is associated with a lower mortality risk, over and above its contribution to total physical activity volume. Methods A total of 46,682 adults (mean age: 64 years) were included in a meta-analysis of nine prospective cohort studies. Each cohort generated tertiles of accelerometry-measured physical activity volume and volume-adjusted MVPA. Hazard ratios (HR, with 95% confidence intervals [CI]) for mortality were estimated separately and in joint models combining volume and MVPA. Data was collected between 2001-2019 and analyzed in 2023. Results During a mean follow-up of nine years, 4,666 deaths were recorded. Higher physical activity volume, and a greater contribution from volume-adjusted MVPA, were each associated with lower mortality hazard in multivariable-adjusted models. Compared to the least active tertile, higher physical activity volume was associated with a lower mortality (HRs: 0.62; 95%CI, 0.58, 0.67 and 0.50; 0.42, 0.60 for ascending tertiles). Similarly, a greater contribution from MVPA was associated with a lower mortality (HRs: 0.94; 95%CI, 0.85, 1.04 and 0.88; 0.79, 0.98). In joint analysis, a lower mortality from higher volume-adjusted MVPA was only observed for the middle tertile of physical activity volume. Conclusions The total volume of physical activity was associated with a lower risk of mortality to a greater extent than the contribution of MVPA to physical activity volume. Integrating any intensity of physical activity into daily life may lower mortality risk in middle aged and older adults, with a small added benefit if the same amount of activity is performed with a higher intensity.