Ecological Momentary Intervention to Replace Sedentary TimeWith Physical Activity to Improve Executive Function in Midlifeand Older Latino Adults:Pilot Randomized Controlled Trial

Background: Exercise interventions often improve moderate to vigorous physical activity, but simultaneously increase sedentarytime due to a compensatory resting response. A higher level of sedentary time is associated with a lower level of executivefunction, while increased moderate to vigorous physical activity is associated with improved global cognition and working memoryamong Latino adults. Latino adults are the fastest-growing minority group in the United States and are at high risk for cognitivedecline, spend more time sedentary compared to non-Hispanic populations, and engage in low levels of physical activity.Interventions that are culturally appropriate for Latino adults to replace sedentary time with physical activity are critically needed. Objective: This study aims to develop and test the feasibility and acceptability of an ecological momentary intervention (EMI;delivered in real time) that is individually designed to replace sedentary time with physical activity in Latino adults. Methods: This pilot study randomized 39 (n=26, 67% female; mean age 61, SD 5.8 years) community-dwelling, Spanish-speakingLatino adults (1:1 allocation) to either a 6-week EMI program designed to replace sitting time with physical activity (20/39, 51%)or physical activity guidelines education (19/39, 49%). The program was conducted on the web and in Spanish. The interventionwas individualized based on individual interview responses. The intervention included the use of a Fitbit activity monitor, weeklydidactic phone meetings, interactive tools (SMS text messages), and coach-delivered feedback. Feasibility and acceptability wereassessed via study satisfaction (Likert scales), motivation (ecological momentary assessment), retention, and compliance. Sedentarytime and physical activity were assessed via 7-day actigraphy. Cognitive performance was assessed via the trail making test partA and B (part B=executive function) and via the National Institutes of Health Toolbox remote cognitive assessment. Statisticalanalysis included a linear model on change score from baseline, adjusting for age, sex, and education, emphasizing effect size. Results: Participant satisfaction with EMI was high (9.4/10), with a high degree of motivation to replace sitting time withphysical activity (9.8/10). The intervention compliance rate was 79% with low difficulty using the Fitbit (1.7/10). Weekly stepcount increased in the intervention group by 5543 steps (group difference: d=0.54; P=.05) and sedentary time decreased by amean 348 (SD 485) minutes (group difference: d=0.47; P=.24) compared to controls, with moderately strong effect sizes. Thetrail making test part B improved in the intervention group (mean -35.26, SD 60.35 seconds), compared to the control group(mean 7.19, SD 46 seconds; group difference: d=0.74; P=.01). No group differences were observed in other cognitive measures. Conclusions: An individualized EMI designed for midlife and older Latino adults has the potential to replace sitting time withphysical activity and improve executive functioning. The intervention was feasible and well received with a high degree ofsatisfaction. Trial Registration: ClinicalTrials.gov NCT04507464; https://tinyurl.com/44c4thk5