The western Society epidemic of life-style-related disease is an impending threat to public health, as well as economy, and calls thus for effective, affordable treatment and prevention strategies. The project has the potential to identify the key cellula r and molecular mechanisms underlying the beneficial effects of physical exercise on heart, arteries, and skeletal muscle in the context of prevention and management of main public diseases through the combination of experimental, clinical and epidemiolog ical studies. Identifying the cellular and molecular mechanisms associated with aerobic fitness is important, because it may help us develop new and better methods to prevent and treat cardiovascular disease. The relationship between physical activity and health has been studied using either a top-down or bottom-up strategy. The top-down approach starts by epidemiological studies, and then works its way towards identifying possible general physiological mechanisms. The bottom-up strategy begins by studyin g the basic molecular mechanisms induced by exercise training, and thence upwards to a coherent view of improved public health. Neither approach has alone been successful in establishing firm links between molecules and public health. There is a lack of a n integrative approach fighting the major public health issues of inactivity, overweight, metabolic syndrome and the subsequent cardiovascular disease/mortality and economical (and social) burden on the society in terms of treatment of life-style related disease. The main focus of the activity of the current project is to combine the two strategies into a more integrative approach bringing epidemiological, experimental and clinical expertise together in the battle against life-style related disease. The n ovelty of the suggested centre is the combination of studies of physical activity ranging from the largest health survey in an unselected population in the world (HUNT-1, 2, 3) all the way down to molecules.