Associations between 24-h movement, mental health and cognitive function among older adults: Review and prospects.

Background: As global life expectancy rises, more countries are entering an era of population aging, posing ongoing challenges to maintaining cognitive and mental health in older adults. Modifiable lifestyle factors are critical for healthy aging. Among these, the 24-h Movement Guidelines (24 h-HMG)-encompassing Physical Activity (PA), Sedentary Behavior (SB), and Sleep (SLP)-have gained increasing attention for their potential benefits. This review systematically summarizes evidence on the associations between these three behaviors and cognitive function and mental health in older adults.

Methods: This review identified 19 studies from PubMed, Web of Science, and Scopus, involving a total of 80,049 participants, all aged over 60 years.

Results: (1) Most of the older adults' time was spent in SB and SLP, while time spent in PA was limited. About 1.60 % to 20.00 % of older adults met all three guideline recommendations. (2) A higher number of guidelines met was positively associated with better cognitive function and mental health. However, different combinations of behaviors were found to have differential associations with cognitive and mental outcomes. (3) Replacing 5-60 min per day of SB with either moderate-to-vigorous physical activity (MVPA) or SLP may yield the greatest cognitive benefits. Replacing 30 min per day of SB or SLP with MVPA was associated with improvements in mental health outcomes, including reduced depressive symptoms and feelings of loneliness. However, these benefits may vary depending on individual sleep needs and should be approached with stratified interventions.

Conclusions: Adherence to the 24 h-HMG contributes to the development of cognitive function and improvements in mental health in older adults. MVPA and SLP represent key targets for effective interventions. Enhancing the proportion of daily time spent in MVPA, ensuring sufficient SLP, and limiting SB may optimize the combined benefits of all three behaviors.