This paper summarizes the results from a number of energy audits and the analysis performed in order to improve indoor conditions and optimize energy use, in Hellenic indoor swimming pools, performed for the European Commission, in the framework of the SAVE program. The aim of this work was to investigate the technical, functional and administrative obstacles for energy conservation in sports centers (including sports halls) and to propose practical and cost-effective solutions for improving their energy efficiency, indoor thermal and visual comfort throughout the year. The work concentrated on retrofitting of existing buildings, although the proposed design and management principles could also be followed in new projects in the area of sports and recreation facilities.