Children spend most of their waking hours sedentary and reducing this behavior has been challenging. Interrupting prolonged episodes of sedentary behavior with active breaks can provide mental and cognitive health benefits. Considering the multifactorial nature of these health aspects, this study aimed to verify the role of body mass index (BMI), cardiorespiratory fitness (CRF), and moderate to vigorous physical activity (MVPA) in the relationship between the break in sedentary time with cognitive and mental health in children. This is a cross-sectional study with 129 children (62 boys), aged between 6 and 11 years (mean 8.73 ± 1.53) from a public school in southern Brazil. For the assessment of fluid intelligence, psychologists applied Raven's Colored Progressive Matrices test. Mental health was measured using the Strengths and Difficulties Questionnaire. Sedentary breaks were measured using accelerometers, and CRF was determined using the 6-min walk test. Generalized linear regression analyses were used to verify associations of sedentary breaks with fluid intelligence and mental health, according to children's BMI, CRF, and MVPA. All models were adjusted for sex, age, somatic maturation, and total time of accelerometer use. Our results indicated that sedentary breaks were associated with fluid intelligence in overweight/obese (β = 0.108; p = 0.021) and physically inactive children (β = 0.083; p = 0.010). Regarding mental health, no association was identified with sedentary breaks. In conclusion, sedentary breaks should be encouraged for the benefits of fluid intelligence, especially in children who do not meet physical activity recommendations and are overweight.
Keywords: Children; cognition; fitness; sedentary living.