Purpose: Sedentary time is associated with an increased risk of mortality and cardiometabolic disease in older adults. However, little is known on the specific associations of (context-specific) sedentary time with geriatric-relevant health outcomes in the oldest-old. Therefore, the aim of this study was to examine the associations between (context-specific) sedentary time and physical, cognitive and psychosocial functioning in the oldest-old.

Methods: A cross-sectional exploratory study, called Healthy 80+, was conducted from March to September 2021 among 86 Flemish older adults (> 80 years). Total sedentary time was measured using Activpal accelerometers, and context-specific sedentary time was measured using a seven-day diary. Physical, cognitive and psychosocial functioning were assessed using the Short Physical Performance Battery (SPPB), the Cambridge Neuropsychological Test Automated Battery (Cantab), and the Short Form 36 (SF-36) Health Survey, respectively. Generalized linear models were performed to examine associations between (context-specific) sedentary time and physical, cognitive and psychosocial functioning.

Results: The oldest-old spend on average 10.48 (±2.57) hours per day sedentary. Highest sedentary time was spent while watching television (165.20 min/day ± 38.15), reading (73.87 min/day ± 11.88), and having meals (56.63 min/day ± 7.74). Preliminary regression analyses, adjusted for gender, age and socio-economic status, showed that total sedentary time was not associated with any of the investigated physical, cognitive and psychosocial functioning outcomes, whereas several associations were found with context-specific sedentary time.

Conclusions: As expected, sedentary time was high among the oldest-old. Additional efforts might be needed to reduce sedentary time in this sample of older adults. Although causal direction between context-specific sedentary time and geriatric-relevant health outcomes remains uncertain, our results suggests that future interventions should better focus on specific types of sedentary behaviour rather than on reducing total sedentary time.  

Purpose: This study aimed to explore the associations between activity fragmentation and frailty status in a population-based US sample of people 50 years and over.

Methods: Cross-sectional data of participants 50 years or over (n=2,586) were used from the 2003-2006 waves of the National Health and Nutrition Examination Survey (NHANES). Frailty status was assessed using a modification of the Fried criteria, validated for application to NHANES data. Physical activity fragmentation was measured by accelerometry. To calculate activity fragmentation, an active-to-sedentary transition probability was calculated as the number of physical activity bouts divided by the total sum of minutes spent in physical activity. Age, gender, ethnicity, education, mobility issues, drinking status, smoking status, and chronic diseases were self-reported in the NHANES study. Body mass index (BMI) was calculated as weight in kilograms divided by height in meters squared. A multivariable ordinal logistic regression model was conducted to examine the association between activity fragmentation and frailty.  

Results: An increment of 30 min/day of physical activity was associated with a decreased likelihood of frailty (OR [95%CI] = 0.91 [0.87 to 0.94]; AME [95%CI] = –0.014 [–0.019 to –0.009]). An increment of 1SD in activity fragmentation was associated with an increased likelihood of frailty (OR [95%CI] = 1.36 [1.13 to 1.664]; AME [95%CI] = 0.048 [0.019 to 0.077]). Compared with participants in the "high activity fragmentation/low physical activity" category, participants in the "low activity fragmentation/low physical activity" and "low activity fragmentation/high physical activity" categories were associated with a lower likelihood of frailty.

Conclusions: Our results suggest that a high fragmented physical activity pattern is associated with frailty in adults and older adults. This association was evident independent of total volume of physical activity and time spent sedentary.

Purpose: Although several interventions have been developed aimed at the reduction of sedentary behavior in older adults, little in-depth information is available on how these complex interventions work in different contexts. Therefore, the aim of this study was to unpack the mechanisms of how existing interventions aimed at the reduction of older adults’ sedentary behavior work or fail to work in particular contexts in order to optimize the development and implementation of future sedentary behavior interventions.

Methods: A realist review was conducted as a first part of the Stand UP Seniors (SUPS) project. The review was structured according to the process recommended by Pawson et al.: (1) research questions were defined, and an initial program theory (IPT) was established, (2) evidence was searched and appraised based on relevance and rigor, (3) data were extracted using back-and-forth movements between the initial program theory and the observed data (i.e. retroduction), and (4) conclusions were drawn. The iterative process resulted in a final program theory that can be used to identify which context(s) trigger(s) which mechanism(s), and in turn might elicit which outcome(s). This theory will be used to inform the second and the third part of the SUPS project, which are, respectively, the development and evaluation of a sedentary behavior intervention in older adults.

Results: The Dual-Process Theory of Sedentary Behavior, and the Elaboration Likelihood Model of Persuasion were used to formulate the IPT. The three main assumptions of the IPT were: (1) the level of motivation, the available opportunities, and the functional capabilities influence how older adults respond to the offered resources in sedentary behavior interventions, (2) resources including social support, feedback on behavior, goal setting, self-monitoring of behavior and information about health consequences are successful to reduce older adults sedentary behavior if the context is conducive, and (3) increasing motivation, awareness, and self-regulation skills are expected responses needed to achieve reductions in older adults’ sedentary behavior.

Conclusions: Successful interventions aimed at the reduction of older adults' sedentary behaviour are complex and should be tailored to older adults' context to trigger cognitive and emotional responses needed to achieve behaviour change.