The mediating role of self-regulation and self-efficacy on moderate to vigorous physical activity change in community-dwelling older adults (≥65 years): An experimental cross-lagged analysis using data from the SITLESS study.

Improving the capacity for physical activity interventions to maintain behaviour change is a key public health concern and an important strategy for the health and independence of older adults. Ways of ensuring effective maintenance of physical activity levels in older adults is unclear. This study includes the objective measure of moderate-vigorous physical activity (MVPA), self-reported self-efficacy, and self-regulation at four timepoints (baseline, intervention completion at 4 months, 12-, and 18-month follow-up) from the SITLESS study, a clinical trial conducted with a cohort of community-dwelling older adults (≥65 years) from Denmark, Germany, Spain, and United Kingdom. A cross-lagged analysis found that self-regulation and self-efficacy may be key determinants of MVPA behaviour in community-dwelling older adults. More specifically, the use of behavioural support strategies represents an important correlate of MVPA behaviour, and its association with MVPA may be mediated by self -regulation and -efficacy in older adults in the short and long term.