Association between physical activity levels, sedentary time, and mild cognitive impairment in older adults

Research indicates that mild cognitive impairment (MCI) in older adults is associated with physical activity levels (PAL) and sedentary behavior duration. However, the precise nature of the relationships between these factors and MCI warrants further investigation.

A cross-sectional survey was conducted from August to October 2025 using cluster sampling in community settings, involving 1,465 older adults. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). PAL were assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF), while sedentary time was self-reported. Logistic regression models were employed to analyze the associations between PAL, sedentary time, and MCI. Restricted cubic spline (RCS) analysis was used to further explore the dose-response relationships. Sensitivity analyses were also performed to validate the observed associations.

Logistic regression analysis revealed that the second and fourth quartiles of PAL (vs. the first quartile) were associated with a significantly reduced risk of MCI (OR = 0.544, p < 0.05 and OR = 0.345, p < 0.05, respectively). The second quartile of sedentary time (vs. the first quartile) was also associated with a significantly lower MCI risk (OR = 0.561, p < 0.05). RCS analysis showed that as PAL increased, the risk of MCI gradually decreased, with the most pronounced cognitive benefit observed at approximately 1,485 MET-min/wk. However, when PAL exceeded 4,000 MET-min/wk., the MCI risk tended to increase. For sedentary time, MCI risk initially decreased and then increased with longer duration. The lowest risk was observed at around 150 min/day, with risk beginning to rise after exceeding 200 min/day. Sensitivity analysis confirmed that the relationships between PAL, sedentary time, and MCI remained robust.

Both physical activity and sedentary time are closely associated with the incidence of MCI in older adults. Maintaining a weekly PAL between 1,485 and 4,000 MET-min/wk. and limiting daily sedentary time to under 200 min may help reduce the risk of MCI.