Mechanical constraints on Nordic ski performance

Abstract

Skiers, coaches, and sports scientists must work within mechanical constraints to improve performance. If Nordic skiing is to be improved by mechanical means, it will be achieved by affecting one or more of the major constraints: gravity, mass, friction, aerodynamic or hydrodynamic lift and drag, and centripetal force. For example, the skier who assumes a tucked position, drafts a competitor, and wears a drag-reducing hood and body suit is reducing aerodynamic constraints. Sliding friction may also be reduced by using specially prepared skis and by selecting skis appropriate for the snow characteristics of the race course. Skin friction hydrodynamic drag may also be affected by ski selection and by special base preparations. Gravity and mass constraints are diminished by using lightweight components, by carrying them in the least costly way, and by minimizing swing weight. The toppling effect of centripetal forces is addressed by leaning into turns. All of these examples address mechanical constraints in a way that reduces physical power requirements, and thus decrease the metabolic power required to ski at a given speed, as well as increasing the maximal speed attainable.