Abstract
BACKGROUND: Burnout in secondary school teachers is an increasing concern. More physical activity (PA) and less sedentary behaviour (SB) may be beneficial to reduce burnout risk in this population. However, no longitudinal evidence on the role of PA-intensities across PA-domains and the role of SB-domains exists. Furthermore, the teaching population, characterized by high PA levels, needs to be studied, as literature showed that leisure PA was less effective to reduce burnout risk in employees with physically demanding jobs. Therefore, this study aimed to examine the causal effects of different PA-intensities and -domains and SB-domains on burnout risk in secondary school teachers. METHODS: In total, 306 Flemish secondary school teachers participated in three measurement moments during the school year 2019–2020 (i.e., start and end of 1st semester, start of 2nd semester). Each measurement moment, burnout risk (including recovery need and the three burnout dimensions: emotional exhaustion, depersonalisation, personal accomplishment), PA-intensities (walking, moderate-intensity PA (MPA) and vigorous-intensity PA (VPA)) in five PA-domains (work, transport, leisure-time, domestic and garden), and SB in three domains (work, transport, leisure-time), as well as sociodemographic factors and work-related factors were assessed. Multiple linear mixed models including selected confounders based on directed acyclic graphs were applied in R. RESULTS: MPA during transport and SB at work were negatively associated with emotional exhaustion (p = 0.021 and p = 0.003, respectively). MPA at work was positively associated with personal accomplishment (p = 0.049), whereas VPA at work was positively associated with recovery need (p = 0.041). Gardening MPA was positively associated with emotional exhaustion (p = 0.010), and both gardening and domestic MPA were positively associated with recovery need (p = 0.016 and p = 0.018, respectively). The (negative) association between leisure-time VPA and emotional exhaustion was borderline significant (p = 0.055). CONCLUSIONS: To reduce burn-out risk, our findings suggest teachers to engage in MPA at work and during transport, VPA during leisure-time, and SB at work, and to limit VPA at work as well as gardening and domestic MPA. Altogether, this study highlights the importance of differentiating between PA-intensities across PA-domains and between SB-domains when addressing burnout risk. Future research should measure additional potential confounding factors and employ longer time intervals. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-025-25505-y.