Physiological effects of technique and rolling resistance in uphill roller skiing

Objective: The double pole technique (DP) has been shown to be more economical than the Vi skate technique (V1) on flat terrain. The objective of the present study was to compare these two techniques during uphill roller skiing. In addition, the physiological effects of changing roller ski rolling resistance was examined for V1. Methods: Five female and five male competitive cross-country skiers roller skied 4-min bouts on a 5.2% incline while physiological measurements were made. Results: Oxygen uptake ((V) over dotO(2)) values averaged 8% greater (P = 0.0004) with V1, whereas rating of perceived exertion (RPE) and blood lactate concentrations were higher (P less than or equal to 0.002) with DP. Doubling the dynamic friction coefficient of the roller skis, which increased external power output by 16-17%, resulted in (V) over dotO(2) values with V1 that averaged 13% higher (P = 0.0006). This magnitude of change in roller ski rolling resistance did not cause a statistical change in the relationship of (V) over dotO(2) with RPE. Conclusions: These findings suggest that 1) grade has little effect on relative economies of DP and V1, possibly because of a lower effectiveness of force application with V1 when going uphill, and 2) large differences ip roller ski rolling resistance should have no effect on the cardiovascular training adaptations that result from uphill roller skiing with V1.