Reliability and criterion validity of the Concept 2 SkiErg™ to assess 1000-m on-snow, time trial performance – a case study

Brendan J O'Brien¹Ryan Worn¹Brad Clark²Matt Spencer^3*

• ¹Federation University Australia, Institute of Health and Wellbeing, Mt Helen, Australia
• ²University of Canberra, Research Institute for Sport and Exercise, Canberra, Australia
• ³Department of Sports Science and Physical Education, Faculty of Health and Sports Sciences, University of Agder, Kristiansand, Norway

Objectives: This study investigated the reliability and criterion validity of the Concept 2 SkiErg™ to assess 1000-m on-snow, time trial performance using the classical double poling technique. Methods: Ten athletes (5 males and females) from a National cross-country ski team participated in the study and completed a 1000-m time trial on snow, as well as two 1000-m time trials on the Concept 2 SkiErg™ in a temperature-controlled room during a 4-day training camp. Results: There was a significant decrease in time from test 1 to test 2 of 4.87 s (238.3 ± 26.1 v 233.4 ± 23.9 s; 95% limits of agreement [LoA]: -5.5, 15.3). The Concept 2 SkiErg™ time-trial had a coefficient of variation (CV) of 1.6% and the standard error of measurement was 3.8 s. When compared to the on-snow time-trial, the Concept 2 SkiErg™ time-trial demonstrated a mean bias of 20.7 s (95% LoA; 11.6, 29.8) and the concordance correlation coefficient was 0.72. Conclusion: The Concept 2 SkiErg™ demonstrated excellent single-trial reliability. However, there was significant proportional bias in the Concept 2 SkiErg™ relative to the on-snow test and agreement between the two was relatively poor. Research using a larger sample and different trial durations is required to further validate the Concept 2 SkiErg™ for cross-country skiing performance testing.