Comparison of oxygen consumption and selected kinematics between and within the 1-skate, 2-skate and offset techniques

Abstract

The 1-skate, 2-skate and offset techniques are the three most prevalent skate-skiing techniques used during cross-country ski racing. Although kinematic differences at maximum velocity have been observed between techniques (Bilodeau et al., 1991, 1996), physiology based criteria for choosing between techniques during a race have not been examined. The primary purpose of this study was to determine any differences in oxygen consumption between the 1-skate, 2-skate and offset when performed by highly trained cross-country ski racers over flat terrain at a submaximum velocity of 5.4 m *s-1. The secondary purpose was to identify the kinematic parameters that may be associated with economical skiing for each of the techniques by examining correlations between kinematic variables and economy for each of the techniques under the same conditions. Eleven male sub-elite cross-country skiers skied behind a snow-machine at a submaximal velocity of 5.4 m*s-1 using the 1-skate, 2-skate or offset exclusively. Oxygen consumption was measured throughout each trial (KB1-C, AeroSport Inc.) to assess economy. Three-dimensional videography (Peak Performance Technologies) was used to measure kinematic parameters. A randomized block ANOVA and Scheffé’s test was used to assess differences in oxygen consumption between techniques. Correlation coefficients between economy (expressed as percentage of VO2Max and HRmax) and selected kinematic parameters were examined to determine the kinematic performance variables associated with the economical performance of each technique. Minute ventilation was observed to be lower (p<0.05) during performance of the 2-skate (84.77 L *min-1) than the 1-skate (91.37 *mi-1 ). This difference was attributed to the increased poling demands of the 1 -skate. Although no other significant physiological differences were observed between techniques, small differences in oxygen consumption between the 1 -skate and 2-skate, representing 2.5% of VOzMax. could potentially be manifested in performance discrepancies at higher, race-specific velocities. Correlations observed between oxygen consumption and the kinem atic parameters suggest that increased gliding tim e and more vigorous application of propulsive forces characterize more economical performance of the 2-skate. Economical performance of the 1-skate appears to feature more sustained poling and increased side-to-side movement of the centre of mass. Future study of between and within group differences for the 1 -skate and 2-skate should be completed at velocities approaching race pace. Few clear findings were observed with the offset and in the future it should be examined on uphill terrain where it is typically performed.