BackgroundThe teaching profession is characterized by high levels of stress and physical complaints, which might be improved through regular participation in physical activity (PA). However, the effect of PA on mental and physical health is not always consistent and depends on the type of PA performed. The aim of this study was to examine the mental, physical, and work-related health of Flemish secondary school teachers and identify the impact on those health variables by demographic and teaching-related factors and various types of PA.MethodsThis study included an online survey conducted across a representative sample of secondary school teachers (n = 1066, average age 40 years; 68 percent female). Level of PA and sitting time were estimated using the International Physical Activity Questionnaire, and perceived mental health and physical health were estimated using the Short Form 36. Work-related factors such as job satisfaction, occupational stress, and absenteeism were also collected. T-tests, ANOVAs, and linear regression analyses were performed.ResultsFlemish secondary school teachers have poorer perceived mental and physical health than a general healthy population. This difference is particularly evident among female teachers, who reported lower perceived health, more occupational stress, and more absent days compared to their male colleagues. Higher participation in leisure-time PA was associated with a more positive perceived health. In contrast, higher levels of occupational PA and sitting time had a negative impact on perceived health. Total amount of PA, total amount of moderate-to-vigorous PA, transportation-related PA, and PA at home were not associated to teachers’ perceived health.ConclusionBecause secondary school teachers’ levels of perceived health are low, they are an important target group for interventions aiming to improve health. Only leisure-time PA was associated with more positive perceived health. This finding may indicate that teachers performing more exercise during leisure time, or in a more autonomous way, may be more resistant to physical and mental health problems. Future research should verify whether promoting leisure-time PA among teachers has the potential to improve their mental and physical health, and counteract the negative associations between teachers’ health and their occupational PA.