Cardiorespiratory fitness and cardiovascular disease risk factors in children: effects of a two-year school-based daily physical activityintervention: The Sogndal school-intervention study

Cardiovascular disease (CVD) is the leading cause of death in the Western world. Several studies have shown that the pathological processes of atherosclerosis begin in childhood and progress throughout life. Consequently, there is a need for preventive strategies early in life, and physical activity is an important tool for primary prevention of CVD. It was recently shown that low cardiorespiratory fitness (CRF) is a strong predictor for clustering of CVD risk factors, and that high CRF is associated with a healthier cardiovascular profile. The school setting is an ideal environment for population-based physical activity interventions. In Norway, schools exist in all municipalities, and most children and adolescents, from the age of six to 16, spend most of their day in school. Hence, the school setting may be the only means in society to reach a large number of children from all socio-economic backgrounds