Light Physical Activity Throughout the Day and Physical Function in Older Adults

Abstract Background Light physical activity (LPA) plays a crucial role in preventing muscle loss and disability in older adults. Since LPA makes up a significant portion of daily activity, understanding how the timing of LPA influences physical function is important for designing effective health interventions. Methods This cross-sectional study investigated the association between the timing of LPA and physical function among 200 older adults (mean age 76.3, 55.5% female) attending the geriatric outpatient clinic at National Taiwan University Hospital. LPA was objectively measured using wrist-worn accelerometers for seven consecutive days. Principal component analysis (PCA) was used to identify distinct patterns of LPA timing. Participants underwent assessments of grip strength, basic mobility, walking speed, and lower limb muscle strength. Multivariable linear regression models were adjusted for potential confounders, including gender, age, moderate-to-vigorous physical activity (MVPA), and accelerometer wear time. Results Our findings revealed that higher levels of LPA during the morning to noon period were positively associated with better performance across all four physical function tests. Moreover, after controlling for relevant confounders, increased LPA in the late afternoon and evening was positively associated with enhanced basic mobility, walking speed, and lower limb muscle strength. Conclusions This study highlights the importance of considering LPA timing when promoting physical function in older adults, independent of MVPA participation. Encouraging LPA, particularly during the morning to noon period, could be a valuable strategy for maintaining and improving physical capabilities in this population. These findings provide actionable insights for clinicians and health professionals when tailoring physical activity recommendations for older adults within geriatric care settings. Key messages • Morning LPA boosts physical function in seniors, enhancing grip, mobility, walking speed, and muscle strength. • Timing of light activity crucial for older adults’ physical health, with morning to noon activity showing most benefits.