The Institute for Outdoor Sport and Environmental Research develops and monitors the “DSV nordic aktiv" centres for the German Ski Association (DSV) and the Foundation for Safety in Skiing (SIS). This is where routes for the Nordic sports: Nordic Walking, Nordic Blading, Nordic Skiing, Trail Running and Nordic Snowshoeing are developed. The concept allows year-round activities on a high-quality network of trails. Modern services and products are designed from a sports science, ecological, economic and tourist point of view. Since 2006, 1659 routes have been developed in Germany in cooperation with the DSV and SIS. This has resulted in a total of more than 4,000 certified cross-country trails and more than 7,000 certified Nordic Walking kilometres. In recent years, 290 DSV centres have been set up in 15 national skiing associations - spread over 11,733 kilometres of measured trails. The trail concept includes design, surveying, classification, homologation, certification, signposting and marketing as a multi-sport product for winter and summer.