Longitudinal approach to assessing maximal aerobic power during growth: the European experience

This review deals with the principle and constraints of conducting longitudinal studies on exercise in children. As with cross-sectional studies, longitudinal ones have advantages and constraints: the different types of such designs as mass studies, population studies, or prospective cohort studies should be therefore selected to minimize their possible drawbacks. Other problems of longitudinal studies, such as the age span studied, time and sequential measurement effects, or interventional effects, have to be controlled by statistical measures and study design. In longitudinal studies ad hoc research groups working in field laboratories are for many reasons more flexible than permanent teams using institutional laboratories. Only direct determinations of maximal aerobic power should be used in longitudinal studies. These should be accompanied by such measurements as body height, body mass, lean body mass, and peak height velocity and by such health indicators as daily physical activity, blood pressure, smoking habits, and blood lipids. Examples for this approach are given in this paper, and general issues of longitudinal studies are discussed from the economic and ethical point of view.