Methodological Guidelines Designed to Improve the Quality of Research on Cross-Country Skiing

Cross-country(XC)ski races involve a variety of formats,two different techniques and tracks with highly variable topography and environmental conditions.In addition,XC skiing is a major component of both Nordic combined and biathlon competi-tions.Research in this area,both in the laboratory and field,encounters certain difficulties that may reduce the reliability and validity of the data obtained,as well as complicate comparisons between studies.Here,13 international experts propose specific guidelines designed to enhance the quality of research and publications on XC skiing,as well as on the biathlon and Nordic combined skiing.We consider biomechanical(kinematic,kinetic and neuromuscular)and physiological methodology(at the systemic and/or muscle level),providing recommendations for standardization/control of the experimental setup.We describe the types of measuring equipment and technology that are most suitable in this context.Moreover,we also deal with certain aspects of nomenclature of the classical and skating sub-techniques.In addition to enhancing the quality of stud-ies on XC skiing,Nordic combined and biathlon,our guidelines should also be of value for sport scientists and coaches in other disciplines where physiological and/or biomechanical measurements are performed in the laboratory and/or outdoors.

Monitoring the Performance of Alpine Skiers with Inertial Motion Units: Practical and Methodological Considerations

Although reliable feedback is crucial to improving the performance of competitive alpine skiers,the coach’s eye may not be sensitive enough to detect small,but highly significant“mistakes”.Monitoring of the performance of alpine ski racers by inertial motion units(IMU)has proven to be of value in this context and here we summarize practical and methodological aspects of this approach.Methodologically,the IMUs employed should combine high sampling frequencies with minimal signal drift.The sensors should be positioned to sense the movement of the bones in a given body segment while being pro-tected as much as possible against impact with the ski gates.The data obtained,often synchronized with input from Global Satellite Navigation Systems(GNSS),are usually refined utilizing advanced biomechanical models and other computerized approaches.In practice,the combination of inertial sensors and GNSS allows accurate monitoring of skiing kinematics(technique)and the movement of the skier’s center-of-mass,also allowing analysis of both whole-body vibrations(WBV)and loss of mechanical energy.Presentation of the findings to coaches and athletes can be facilitated by synchronizing them with video recordings.Recent advances in IMU technology,including miniaturization,wireless communication,direct stor-age of data in the cloud,and processing with artificial intelligence may allow these sensors,in-combination with GNSS,to become real-time virtual alpine ski coaches,perhaps the next step in the development of this sport.