Granö loeng. Abstract of the Granö lecture, Tartu, May 14, 2009 Roles of Research in Promoting Health by Physical Activity There is wide consensus among people, health professionals, and politicians that physical activity is healthy. This consensus has not been and will not be sufficient, however, to lead to large willingness among people to increase their physical activity, not to its systematic recommendation by health professionals, nor to investments in its serious promotion by politicians. Stronger measures are needed to increase awareness and credibility of the value of physical activity for health. What are or what could be the roles of research in strengthening promotion of physical activity for health?