This book contains the proceedings of the Fourth International Congress on Science and Skiing, which was held at St. Christoph am Arlberg, Tyrol, Austria. The conference was organized and hosted by the Department of Sport Science at the University of Salzburg, Austria, and by the Christian Doppler Laboratory 'Biomechanics in Skiing', Salzburg, Austria. It was also part of the programs of the steering group 'Science in Skiing' of the World Commission of Sports Science and contains a broad spectrum of current research work in Alpine and Nordic skiing and in snowboarding. In the proceedings of this congress, the keynotes and invited lectures as well as the oral presentations are published. The manuscripts were subject to peer review and editorial judgement prior to acceptance.