Longitudinal association of leisure time physical activity with allostatic load in midlife

Abstract Background Allostatic load (AL) refers to the cumulative physiological wear and tear on the body caused by chronic stress. Prolonged secretion of stress hormones can lead to adverse health outcomes; however, the long-term association between physical activity (PA) and overall well-being is well-established, with numerous studies demonstrating PA's positive impact on physical and mental health. The long-term relation between PA and cumulative stress remains unclear. This study investigated the longitudinal association between leisure-time physical activity (LTPA) with AL in midlife. Methods Participants were drawn from the Northern Finland Birth Cohort 1966, with data collected at ages 31 and 46 for this study. The final sample included 3,358 individuals who completed the PA questionnaires at both time points and underwent clinical examinations to assess biomarkers of AL at age 46. LTPA was self-reported and categorized into four PA trajectory groups (stable inactive, increased, decreased, and stable active) based on meeting the WHO recommendation on PA at both time points. AL was assessed using 13 biomarkers from cardiovascular, neuroendocrine, immune and metabolic systems connected to overall stress, and Poisson regression was applied to examine the association between LTPA and AL. Results From early adulthood to midlife, participants with stable inactivity (rate ratio, RR = 1.18, 95% confidence interval, CI: 1.11-1.25) or decreasing LTPA (RR = 1.10, 95% CI: 1.02-1.19) were at a higher risk of AL accumulation compared to those with stable active PA. Conclusions Both stable inactivity and decreasing LTPA from early adulthood to midlife were associated with greater accumulation of AL. Meeting current PA recommendations may offer protection against the accumulation of AL. Key messages • Meeting the PA recommendations from early to mid-adulthood may reduce physiological stress accumulation by midlife. • Promoting PA throughout adulthood could help lower long-term health risks linked to chronic stress.