POLING FORCES DURING ROLLER SKIING - EFFECTS OF GRADE

Purpose: A substantial proportion of the propulsive forces required fo r uphill skiing are generated from the upper body, but no study has sy stematically examined poling forces at different slopes. In the presen t experiment, poling forces and tinting were examined during roller sk iing on 2.1% and 5.1% uphills. Methods: Nine highly skilled cross-coun try skiers roller skied at paced submaximal and at maximal speeds usin g the V1 skate (V1) and double pole (DP) techniques. Poling forces and timing were measured with piezoelectric transducers. Results: Peak fo rce (PF), average force (AF) and average force over the entire cycle ( ACF) were significantly greater (P < 0.01) at the steeper grade with b oth techniques. Values for the ratio of V1 to DP did not differ betwee n the two grades for PF, AF, and ACF but tended to increase with veloc ity for both techniques. With both V1 and DP, upper body recovery time was shorter (P < 0.01) at the steeper grade, and cycle rate was great er (P < 0.01) at the steeper grade. Conclusions: We conclude that 1) t he relative demands on the upper body with V1 compared with DP were si milar between the two grades, and 2) the responses to an elevation in grade of increased poling forces, shortened poling recovery times, and increased cycle rate are comparable to the responses to an increase i n speed.