EFFECTS OF DORSIFLEXION ON ENERGY EXPENDITURE DURING CROSS·COUNTRY SKIING USING THE V1 SKATE TECHNIQUE

Competitive cross-country skiing involves race events of different distances conducted over natural terrain. The primary objective of the skier is to cover the race distance as quickly as possible. This requires the athlete to achieve a high speed to energy expenditure ratio while maintaining physiological strain within tolerable limits. Thus, the influence of various mechanical techniques of skiing on energy expenditure and physiological strain is of interest to skiers. There has been interest concerning the possible effects of various joint angles on skiing techniques (Smith, 1992). More specifically, ankle flexion seems to play some role in reducing the abovementioned speed to energy expenditure ratio. An increase in dorsiflexion may be reflective of a more forward center of mass position and a degree of force oriented downward and rearward onto the ski. A portion of this force may be propulsive. As a result, increased dorsiflexion may provide lower oxygen demands for a given velocity of movement. The purpose of this study was to examine whether oxygen uptake and energy expenditure vary with different degrees of ankle dorsiflexion during the V1 skating technique. A second objective was to determine if a degree exists where dorsiflexion does not influence energy expenditure during the V1 skating technique