Unique characterization of elite alpine skiers
In two research articles published recently in the highly rated journal Frontiers in Physiology, Olympic skiers were studied during training and competition. These studies show that slalom skiers are subjected to the greatest forces with one day of training as many as 700 turns, each of which can load the body with up to five times its own weight.
– The courses in the technical disciplines involve a larger number of and more rapid changes in direction, as well as higher ground reaction forces, explains H-C Holmberg, Professor at the Swedish Winter Sports Research Centre at Mid Sweden University in Åre-Östersund.
The article entitled “The Training of Olympic Alpine Ski Racers” describes for the first time how the elite skiers from four of the major alpine ski racing nations prepared for the Olympic Games in South Korea in 2018. Typically, these skiers train and compete on snow 130–150 days each year. Depending on the time of year, slalom training consists of 2-12 runs, each involving 40-60 turns, with each turn lasting about 0.8 seconds, resulting overall in 100–700 changes in direction during any individual session.
– Each of these changes involves a sharp increase in ground reaction force, which can be as high as five times body weight, the highest for all skiing disciplines, says Mathias Gilgien, Associate Professor at the Norwegian School of Sports Sciences in Oslo.
In comparison, giant slalom training consists of 2-12 runs, each involving 25-50 turns, with each turn lasting about 1.4 seconds, resulting in a total of 50–600 changes in direction, each involving maximal ground reaction forces of approximately 3.2 times body weight.
– Alpine ski racing requires mastery of a broad spectrum of physical, technical, mental, and social skills. These articles have resulted from a broad collaboration between leading researchers in six different countries. They document unique information obtained from interviews with the coaching staff and describing the athletes’ typical exercise programs with respect to physical conditioning, ski training and periodization, says H-C Holmberg.
Alpine skiing has been an Olympic event since the first Winter Games in 1936 and at the World Championships the skiers compete in four main events: slalom, giant slalom, super-G and downhill. These articles conclude that the average duration of a single run in slalom is 52 seconds and the average speed 54 km/h, while in giant slalom an average run of 77 s has an average speed of 65 and maximal speed of 85 km/h. In the case of Super-G a single run takes 93 seconds, with average and maximal speeds of 86 and 110 km/h, respectively, and for downhill the corresponding values are 121 seconds and 94 and 150 km/h.
– Substantial improvements in slope preparation, design of courses, equipment, and the skier’s skills have all helped Alpine skiing attain its present significance. Improved snow preparation has resulted in harder surfaces and improved equipment allows more direct interaction between the skier and snow, explains Professor Matej Supej at University of Ljubljana.
The wide variety of terrain, slopes, gate setups and snow conditions involved requires skiers to continuously adapt, alternating between turning by carving or skidding. The technical complexity places a premium on minimizing energy dissipation, employing strategies and ski equipment that minimize both ski-snow friction and aerodynamic drag.
– Information about multiple split times along the racing course, in combination with analysis of the trajectory and speed can be utilized to enhance performance. Although the biomechanics of alpine skiing have improved significantly, several questions concerning optimization of a skier’s performance remain to be investigated, according to H-C Holmberg.
Contacts:
Professor H-C Holmberg at Mid Sweden University in Östersund, Sweden; hc.holmberg@miun.se
Professor Matej Supej at University of Ljubljana, Slovenia; Matej.Supej@fsp.uni-lj.si
Associate Professor Mathias Gilgien at the Norwegian School of Sports Sciences in Oslo; matthias.gilgien@nih.no
Publications:
- Gilgien M, Reid R, Raschner C, Supej M and Holmberg H-C. The Training of Olympic Alpine Ski Racers. Frontiers in Physiology Feb 2019; https://www.frontiersin.org/articles/10.3389/fphys.2018.01772/full
- Supej M, Holmberg H-C, Recent Kinematic and Kinetic Advances in Olympic Alpine Skiing: Pyeongchang and Beyond, Frontiers in Physiology Dec 2018; https://www.frontiersin.org/articles/10.3389/fphys.2019.00111/abstract