Effect of a Scalable School-Based Intervention on Cardiorespiratory Fitness in Children

Cardiorespiratory fitness is an important marker of childhood health and low fitness levels are a risk factor for disease later in life. Levels of children's fitness have declined in recent decades. Whether school-based physical activity interventions can increase fitness at the population level remains unclear.To evaluate the effect of an internet-based intervention on children's cardiorespiratory fitness across a large number of schools.In...