Light-Intensity Physical Activity and Life Expectancy: National Health and Nutrition Survey

Introduction. Quantifying the number of years gained (YLG) associated with light-intensity physical activity (LPA) may be important for risk communication in public health. With no studies having examined the role of LPA in life expectancy, this study aims to quantify YLG from LPA in a population-based US sample. Methods. This study used data from 6,636 participants in the National Health and Nutrition Examination Survey (2003-2006). The analyses were conducted in 2020. LPA was categorized into low, medium, and high based on tertiles, and survival models were applied to estimate YLG from each LPA group. The analyses were repeated in participants with MVPA above or below the median. Results. During a mean follow-up of 11 years and 55,520 person-years, 994 deaths were recorded. At age 20, participants with low, medium and high LPA had a predicted life expectancy of 55.70 (48.70 – 62.70), 58.96 (52.17 – 65.75) and 60.60 (54.03 – 67.18) years, suggesting significant YLG from medium and high levels of LPA of 3.45 (0.77 – 6.12) and 5.24 (1.88 – 8.60) years. Corresponding YLG at age 45 and 65 was 2.93 (0.40 – 5.47) and 1.98 (0.03 – 3.94) years for the medium LPA group, and 4.53 (1.26 – 7.80) and 3.10 (0.42 – 5.78) years for the high LPA group. This association was significant in participants with below-median MVPA but not for those with above-median MVPA. Conclusion. LPA may extend life expectancy. Given the low prevalence of MVPA in populations, physical activity promotion efforts may capitalise on emerging evidence on LPA, particularly among the most inactive groups