Abstract

Aims: To investigate how physical activity (PA) volume, intensity, duration, and fragmentation are associated with the risk of all-cause and cardiovascular disease mortality. To produce centile curves for PA volume and intensity representative of US adults.

Methods: This study is based on the observational 2011-2014 National Health and Nutrition Examination Survey (NHANES). Adults (age ≥20) with valid accelerometer, covariate, and mortality data were included. Average acceleration (AvAcc), intensity gradient (IG), and total PA served as proxies for volume, intensity, and duration of PA, respectively. Weighted Cox proportional hazard models estimated associations between outcome and PA metrics.

Results: In 7518 participants (52.0% women, weighted median age 49), there were curvilinear inverse dose-response relationships of all-cause mortality risk (81-month follow-up) with both AvAcc (-14.4% [95% CI -8.3 to -20.1%] risk reduction from 25th to 50th percentile) and IG (-37.1% [95% CI -30.0 to -43.4%] risk reduction from 25th to 50th percentile), but for cardiovascular disease mortality risk (N=7016, 82-month follow-up) only with IG (-41.0% [95% CI -26.7 to -52.4%] risk reduction from the 25th to 50th percentile). These relationships plateau at AvAcc: ∼35-45 mg and IG: -2.7 to -2.5. Associations of PA with all-cause and cardiovascular disease mortality are primarily driven by intensity and secondary by volume. Centile curves for volume and intensity were generated.

Conclusion: Intensity is a main driver of reduced mortality risk suggesting that the intensity of PA rather than the quantity matters for longevity. The centile curves offer guidance for achieving desirable PA levels for longevity.