Patterns of Nutrient Intake among Male and Female High School-Aged Cross-Country Skiers and Speed Skaters

This study aimed to determine the appropriate nutritional intakes and dietary habits of high school-aged cross-country skiers and speed skaters. The subjects, all high school students from N Prefecture, included 18 male cross-country skiers, 5 male speed skaters, 10 female cross-country ski players and 4 female speed skaters. Physical measurements, food intake frequency survey results, bone mineral density and exercise stress test outcomes, and lactic acid measurements were evaluated. Female athletes in both sports had higher body fat percentages relative to the average range stated for female athletes. Male speed skaters had a significantly higher maximum oxygen in-take than that male cross-country skiers did. By contrast, this parameter did not differ significantly among female athletes. A negative correlation was observed between the fat free mass and muscle mass, and a positive correlation was observed among the body fat percentage, fat percentage, and fat mass. Both male and female athletes had protein intake ratios within the reference ranges. All athletes except male speed skaters had lipid energy ratios that were higher than the upper limit of the reference value. Both male and female athletes also reported carbohydrate energy ratios within the reference ranges, but had cereal energy ratios below the reference values. Athletes should pay attention to the ingestion of various nutrients to ensure a sufficient energy intake. Accordingly, adolescent athletes should consume daily meals containing a good balance of staple foods, main dishes, side dishes, milk and other dairy products, and fruits.

我国优秀自由式滑雪空中技巧运动员体能水平评价的研究

以文献资料法、问卷调查法、测试法及数理统计法,对备战第22届冬奥会国家自由式滑雪空中技巧一、二线运动员体能水平构成指标进行筛选、赋权和分析,建立了优秀自由式滑雪空中技巧运动员体能水平的评价标准。研究表明:反映我国空中技巧运动员体能水平的三级指标是:跟腱长、腰围/身高*100、骨盆宽、克托莱指数、肺活量、相对平均无氧功率、血红蛋白、高翻、12分钟跑、灵敏跑;对各级评价指标的权重中,运动素质对体能水平起决定性作用,力量和核心稳定指标权重较大,身体形态指标中腰围/身高*100的权重较大,身体机能指标中相对平均无氧功率、血红蛋白的权重较大。

自由式滑雪女子空中技巧优秀运动员下肢肌力与静态平衡能力特征

采用等速测试和平衡测试方法,对我国优秀自由式滑雪空中技巧女子运动员的髋关节、膝关节屈肌力和伸肌力以及4种站姿下的静态平衡能力特征进行研究。结果表明髋关节右侧屈伸肌力、屈伸肌力比、平均功率值稍大于左侧屈肌力量,膝关节伸肌左、右侧单位体重峰力矩和左、右侧平均功率4个指标数值均大于屈肌,在60°/s（慢速）和240°/s（快速）不同的测试速度下,单位体重屈伸峰力矩、屈伸平均功率、屈伸肌力、平均功率随着测试速度的增加出现了显著性差异;正常双脚站立的平衡性大于单脚站立的平衡性。建议合理控制体重及均衡的训练肌肉力量,在适度提高运动速度的情况下,加强下肢伸肌力量的训练,为运动员进行针对性的力量训练、训练后肌肉效果的评价、运动员选材提供科学依据及有价值的理论参考。

精英短距离越野滑雪运动员竞技表现特征及其关键影响因素分析

通过文献和逻辑分析法,对世界级精英短距离越野滑雪运动员在多轮次比赛中表现的配速策略、速度特征以及单轮赛中各赛段速度、技术特征进行分析并讨论影响短距离比赛竞技表现的关键因素。研究认为:生理机能系统、神经肌肉工作系统和身体形态特征是影响和决定短距离越野滑雪运动员竞技表现的重要因素;其中,有氧代谢能力、无氧代谢能力、工作效率、乳酸代谢和疲劳恢复能力是影响运动员多轮制比赛中高速均衡性配速策略的关键指标;上肢爆发力、上肢力量耐力、肌肉类型、神经协调能力是影响运动员选择更高档位滑行技术、高滑频、长滑长技术表现特征的关键指标;同时,身高、体质量和瘦体重尤其是上肢力量耐力表现是影响运动员速度耐力的关键指标。研究结合对世界级精英短距离年度、阶段训练模式的分析,对我国高水平短距离越野滑雪训练提出相关建议:1)以发展有氧代谢能力为基础,要高度重视中低强度有氧耐力训练;强化无氧耐力能力训练,尤其是以糖酵解无氧供能强度为主的高强度训练,提高以有氧代谢为根基的无氧耐力水平;2)注重发展专项力量与专项速度,加强专项力量耐力尤其是上肢专项力量耐力训练和单一技术的专项速度能力训练;3)重视滑行技术效率和动作经济性训练,特别是加强主要滑行技术动作、特定地形地段技术效率和经济性的专门性训练;4)加强科学训练监控、预防损伤和疲劳积累,积极防控重大公共卫生等事件,以保障高水平越野滑雪训练不间断。