Relationship between Sedentary Time, Physical Activity and Multiple Lifestyle Factors in Children

An improved understanding of relationships between moderate-to-vigorous physical activity (MVPA), screen-time and lifestyle factors is imperative for developing interventions, yet few studies have explored such relationships simultaneously. Therefore, the study’s aim was to examine the relationship between sufficient MVPA (≥60 min·day–1) and excessive screen-time (≥2 h·day–1) with lifestyle factors in children. In total, 756 children (10.4±0.6 years) completed a questionnaire, which assessed sleep duration, MVPA, homework/reading, screen-time and diet, and a 20 metre multi-stage shuttle run test to assess cardiorespiratory fitness (CRF). Body mass and stature were measured and used to calculate BMI (body mass index) for age/sex z-scores. Fruit and vegetable consumption and CRF were positively associated with sufficient MVPA, irrespective of sex (p < 0.05). Excessive screen-time was positively associated with sugary snack consumption in boys and girls, and diet soft drink intake in boys (p < 0.05). In addition, excessive screen-time was negatively associated with MVPA before school for both boys and girls, as well as with sleep duration and fruit and vegetable consumption for girls (p < 0.05). Sufficient MVPA and excessive screen-time were associated with healthy and unhealthy factors, respectively, with relationships sometimes differing by sex. Future health promoting interventions should consider targeting change in multiple lifestyle factors.