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The physiological demands of cross-country skiing require competitive skiers to have high maximal oxygen uptakes and anaerobic thresholds. Anaerobic capacity has a relatively less important role, but may be of greater importance today with the faster race velocities resulting from the new skiing techniques of ski skating. Although use of the ski skating techniques results in faster race velocities than the classical techniques, it has been found that under some conditions the double-pole technique is more economical than other skiing techniques. It is suggested that this results from a more effective storage and recovery of elastic energy, a greater proportion of the forces being directed along the line of travel, and a lower air resistance due to greater trunk and hip flexion with the double-pole technique. The greater economy of the double-pole technique suggests that this may be advantageous in certain race conditions if the upper body is adequately prepared. The greater propulsive forces generated with the upper body with ski skating also suggest that training of the upper body should receive more emphasis. The potential cardiovascular adaptations from cross-country ski training appear to be similar for the classical and skating techniques, yet training specificity is important for optimal performance. 相似文献
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William F. Brazziel Ph.D. 《Innovative Higher Education》1988,12(2):126-130
The Ph.D. program of the RAND Graduate School is one of the more innovative programs in America. The dynamics of innovation, e.g., environmental press as the engine of change and creativity as the wellspring of innovative programming, are illustrated vividly in the beginnings of the RAND corporation and its establishment of the RAND Graduate School to operate a free-standing Ph.D. program in policy analysis. Colleges and universities have much to learn-and nothing to fear-from this corporate newcomer to graduate education. Their own innovative efforts in graduate education can be enhanced through careful study of the RAND experience. 相似文献
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