ISI Ski is an offer for those who want to add a combination sport to their main sport. Either because your main sport is seasonal, or simply because you love. Main sports at ISI sports folk high school. Choose from five main sports courses: Fit to Fight, football (soccer), golf, handball and equestrian sports. ISI Fitness. Get a unique badminton experience in Denmark at ISI Idrætshøjskole. . At ISI, you have the opportunity to combine your main sport with a combination sport. ISI Sports Folk High School's club fitness instructor programme is a course you can choose to do in combination with your main sport. If you do, it means that you. The main difference between the two courses is the approach to development. At ISI Football Academy the starting point is a personalised master plan, which. Handball at ISI Sports High School is for those who have handball running through their veins and who would like to test their talent in an intense handball.