The relationship between general upper-body strength and pole force measurements, and their predictive power regarding double poling sprint performance

In recent years, there is an increasing importance of double poling (DP) performance regarding the outcome in classic cross-country skiing (XCS) races. So far, different approaches were used to predict DP performance but there is a lack of knowledge how general strength parameters are related to DP performance parameters gathered from in field-test situations. Therefore, the aim of this study was to determine the relationship between general strength measurements of different upper-body segments and pole force measurements during a DP sprint exercise. In addition, multiple linear regressions were calculated to determine the predictive power of theses variables regarding DP sprint performance, represented as maximum velocity. Thirteen none-elite cross-country skiers performed two 60 m DP sprints at maximal speed on a tartan track using roller skis. In addition, maximum isometric and concentric strength tests were performed on a motor-driven dyna-mometer with four major upper-body segments (trunk flexion / extension, shoulder / elbow extension). Especially the mean pole force and the strength test parameters correlated significantly (r ≥ 0.615) in all except one comparison. However, regression analyses revealed that neither pole force parameters (R² = 0.495) nor isometric (R² = 0.456) or dynamic (R² = 0.596) strength test parameters could predict the DP performance significantly. This study showed that standardized isokinetic strength tests could be used to estimate pole force capabilities of XCS athletes. However, pole-force and strength test parameters failed to predict significantly maximal velocity during a DP sprint exercise, which might be attributed to the non-elite subject group.