INTRODUCTION: Bosco (1997) developed a power endurance test for ski racers, suggesting that speed endurance measured with continuous jumps is the most important capacity for skiers. Bosco documented his work with Italian skiers (1994, 1997), but no subsequent published studies have used his or similar tests. This study presents an alternative power endurance test, and examines the effect of summer training on power endurance. METHOD: 10 female members of the Austrian Ski Federation junior alpine ski team were tested in the spring and in the fall of 2006. The athletes performed 42 continuous counter movement jumps (CMJ) on a force platform (SPSport) with a loaded barbell equivalent to 20% of the athlete's bodyweight. The athletes jumped every 2.5 seconds (test duration was 1 minute, 45 seconds), pausing briefly between jumps to avoid reaction jumps. Before the test individual CMJ were performed as a reference to compare to the first test CMJ. Ground reaction force data were used to calculate absolute peak power (Pmax), and jump height. For analysts the CMJ were divided into 7 series of 6 jumps, and the means of each parameter for all jump series were calculated. Decline for both parameters was the difference between the first series and the other series. For statistical analysis (SPSS 15.0 for Windows) paired t-tests compared means of reference CMJ and first CMJ of the power endurance test, and means of the spring and fall tests. Level of significance was set at p<0,05 RESULTS: First test CMJ (Pmax and jump height) were signiflcantly different from reference CMJ in the spring, but not «n the fall. Relative to reference CMJ, spring first CMJ were 94% (Pmax) and 91% (jump height) and fall first CMJ were 99% (Pmax) and 98% (jump height). First series and last series jump heights in the spring were 22.5cm and 19.7cm, respectively; and 23.6cm and 21.0cm in the fall. There were significant increases frorn spring to fall in Pmax and jump height but only in the first and last series of jumps. Decline in both Parameters did not improve from spring to fall. DISCUSSION & CONCLUSION: The athletes improved over the summer, but only in the first and last series of jumps. This indicates that the training was somewhat effective, when this test is used to evaluate training. A problem in this study is that reference CMJ indicate that the athletes did not jump maximally in the spring tests but were closer to maximum in the fall. This would affect the decline in Parameters and a maximal effort in the spring would have produced larger declines showing more improvement over the summer. This test is part of preseason testing and in time more athletes will be tested over more seasons. Power and power endurance can then be compared to FIS points in each season and longitudinalty.
© Copyright 2009 Science and Skiing IV. Veröffentlicht von Meyer & Meyer. Alle Rechte vorbehalten.