My research focuses on the effectiveness analyses of exercise programmes on cardiometabolic fitness, motor development and metabolic health in children and adults. The focus of interest is the research of the health-enhancing exercise dose ("trainability") and the development of cardio-respiratory exercise testing methods (lactate diagnostics, gas metabolism measurement) with regard to energy metabolism. In this context, we were able to demonstrate that certain gene variants (PGC-1a) can prevent the training effect, measured by mechanical performance at ventilatory indices. We showed further that certain exercise modalities exhibit a very specific training effect concerning endurance performance level and strength of untrained individuals, i.e. no "exercise fits all untrained people". In field studies, we were able to show that the motor fitness of older people could be significantly improved with information technology-supported long-term programmes (Fit-mit-Ilse). The research programme is complemented by the analysis of indicators that focus on participation in health-oriented physical activity and training programmes to inform the development of physical activity recommendations.