Effect of isotemporal substitution of sedentary behavior with different intensities of physical activity on the muscle function of older adults in the context of a medical center

Abstract

Background Engaging in physical activity and reducing sedentary time in daily life may enable older individuals to maintain muscle mass. This study aimed to investigate the effects of replacing sedentary behavior with light physical activity (LPA) or moderate-to-vigorous physical activity (MVPA) on the muscle function of older adults at a medical center in Taiwan. Methods We recruited 141 older adults (51.1% men; 81.1 ± 6.9 years old) and asked them to wear a triaxial accelerometer on the waist to measure their sedentary behavior and physical activity. Functional performance was assessed based on handgrip strength, Timed Up and Go (TUG) test, gait speed, and five-times-sit-to-stand test (5XSST). Isotemporal substitution analysis was performed to examine the effect of substituting 60 min of sedentary time with 60 min of LPA, MVPA, and combined LPA and MVPA in different proportions. Results Reallocating 60 min of sedentary behavior per day to LPA was associated with better handgrip strength (Beta [B] = 1.587, 95% confidence interval [CI] = 0.706, 2.468), TUG test findings (B = -1.415, 95% CI = -2.186, -0.643), and gait speed (B = 0.042, 95% CI = 0.007, 0.078). Reallocating 60 min of sedentary behavior per day to MVPA was associated with better gait speed (B = 0.105, 95% CI = 0.018, 0.193) and 5XSST findings (B = -0.060, 95% CI = -0.117, -0.003). In addition, each 5-min increment in MVPA in the total physical activity replacing 60 min of sedentary behavior per day resulted in greater gait speed. Replacing 60 min of sedentary behavior with 30-min of LPA and 30-min of MVPA per day significantly decreased the 5XSST test time. Conclusion Our study indicates that introducing LPA and a combination of LPA and MVPA to specifically replace sedentary behavior may help maintain muscle function in older adults.

Sociodemographic, Behavioural, and Health Factors Associated with Sedentary Behaviour in Community-Dwelling Older Adults: A Nationwide Cross-Sectional Study

“…Considering the lack of research into markers of sedentary behaviour in older adults, the results of the current study can contribute to the future development of a robust ecologic model of sedentary behaviour in the older population. Recent studies have consistently suggested that replacing sedentary behaviour with light or moderate-to-vigorous physical activity leads to better health outcomes, including improved muscle function and cardiometabolic health [47,48]. By considering factors associated with sedentary behaviour and ecologic models for sedentary behaviour, healthcare professionals can identify high-risk groups with prolonged sedentary times in the older population and develop appropriate intervention strategies.…”

Association between dynapenia and cognitive decline in community‐dwelling older Japanese adults: The IRIDE Cohort Study

“…Dynapenia is often defined as a condition in which muscle weakness occurs with preserved muscle mass. 14,15 Sarcopenia and dynapenia are conceptually distinct, based on the idea that age-related muscle weakness is only partially explained by a decrease in muscle mass. 16 Understanding the link between dynapenia and cognitive decline may help identify a novel group of older individuals who would benefit from interventions to mitigate cognitive decline.…”