ABSTRACT
Clinical markers of chronic disease in adulthood like atherosclerosis, obesity and osteoporosis are due to lifelong processes that originate in childhood with physical inactivity and low aerobic fitness as key players in the high burden of chronic disease.[1] In children, both factors are associated with increasing prevalence of cardiovascular risk factors[2], [3] even independent of body weight.[4] There is strong evidence that high
aerobic fitness and physical activity protect adults-with or without increased body fat-from increased morbidity and mortality. [5] Yet, aerobic performance levels in youth have almost globally decreased over the last decades[6] and not even half of the children meet physical activity recommendations. [7]
The importance of primary prevention by promoting physical activity in general[8] as well as in the scope childhood obesity has become indisputable,[9] as most pediatric obesity treatment interventions are marked by small changes in adiposity,[10] a substantial relapse rate and by a strong tracking of overweight into adulthood.[11] Schoolbased intervention studies promoting a healthy lifestyle have shown favourable immediate health effects.[12] However, there is a striking paucity of information on long-term follow-up especially of high-quality randomised, controlled, theory driven trials that had shown effi - cacy at the end of their interventions.[12], [13] Therefore, we report the 3-year follow-up results of a cluster-randomised, controlled trial (“Kinder-und Jugendsportstudie”; KISS) comparing a school-based stringent physical activity program to traditional physical education during one school-year. This trial has shown benefi cial short-term effects on aerobic fi tness, physical activity, body fat and a composite cardiovascular risk factor score.[14]
5.2 METHODS
5.2.1 ETHICS STATEMENT
The study was approved by the ethics committees of the University of Basel and the Swiss Federal Institute of Technology Zurich, as well as by the Cantonal Ethical Committee of Aargau, Switzerland. Written informed consent was provided by at least one parent and all children gave their assent for participation to the whole study and specifically for the blood withdrawal. The protocol for this trial and supporting CONSORT checklist are available as supporting information; see Checklist S1 and Protocol S1.
