24-Hour Movement Behavior Predict Working Memory Across Time In Older Adults: National Health And Aging Trends Study

TL;DR

This study shows that physical activity and sleep can improve working memory in older adults over time, while too much sitting can harm it.

Contribution

The study reveals longitudinal associations between 24-hour movement behaviors and working memory decline in older adults.

Findings

More sedentary time at T1 and T2 predicted lower working memory at T2 and T3.

Increased MVPA and LPA at earlier time points predicted better working memory at later time points.

Longer sleep duration at T1 was linked to better working memory at T2.

Abstract

Cross-sectional studies have identified associations between 24-hour movement behaviors — moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), sedentary time (SED), and sleep — and cognitive outcomes. However, it remains unclear how these behaviors, measured at a single time point, predict older adults’ cognitive outcomes over time. This study investigated the longitudinal relationship between 24-hour movement behaviors and subsequent working memory in older adults, using three waves of follow-up data (2021–2023) from 492 U.S. Medicare beneficiaries aged 65 and older in the National Health and Aging Trends Study (NHATS). Structural equation modeling with an autoregressive cross-lagged panel design revealed that a 60-minute increase in SED at Time 1(T1) and Time 2(T2) predicted declines in working memory at T2 (B = -0.02, p < 0.001) and Time 3 (T3) (B = -0.013, p = 0.004), respectively. Conversely, a 15-minute increase in MVPA at T1 was associated with improved working memory (B = 0.013, p = 0.01) at T2, and increases in MVPA at T2 predicted better working memory at T3 (B = 0.019, p < 0.001). Similarly, a 60-minute increase in LPA at T1 and T2 predicted better working memory at T2 (B = 0.02, p < 0.01) and T3 (B = 0.03, p = 0.001), respectively. Notably, sleep duration at T1 was positively associated with working memory at T2 (B = 0.016, p = 0.008). These findings suggest that MVPA, LPA, and adequate sleep may support cognitive function over time, while prolonged sedentary behavior may be detrimental.