首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   6篇
  免费   0篇
教育   2篇
科学研究   1篇
体育   3篇
  2013年   2篇
  2006年   1篇
  2005年   1篇
  2001年   1篇
  1999年   1篇
排序方式: 共有6条查询结果,搜索用时 109 毫秒
1
1.
2.
The aim of this study was to determine the hormonal responses, which are dependent on the sleep wake cycle, to strenuous physical exercise. Exercise was performed after different nocturnal regimens: (i) a baseline night preceded by a habituation night; (ii) two nights of partial sleep deprivation caused by a delayed bedtime or by an early awakening; and (iii) two nights of sleep after administration of either a hypnotic compound (10 mg zolpidem) or a placebo. Eight well-trained male endurance athletes with a maximal oxygen uptake of 63.5 +/- 3.8 ml x kg(-1) x min(-1) (mean value +/- s(x)) were selected on the basis of their sleeping habits and their physical training. Polygraphic recordings of EEG showed that both nights with partial sleep loss led to a decrease (P< 0.01) in stage 2 and rapid eye movement sleep. A delayed bedtime also led to a decrease (P < 0.05) in stage 1 sleep. Zolpidem had no effect on the different stages of sleep. During the afternoon after an experimental night, exercise was performed on a cycle ergometer. After a 10-min warm-up, the participants performed 30 min steady-state cycling at 75% VO(2-max) followed by a progressively increased workload until exhaustion. The recovery period lasted 30 min. Plasma growth hormone, prolactin, cortisol, catecholamine and lactate concentrations were measured at rest, during exercise and after recovery. The concentration of plasma growth hormone and catecholamine were not affected by partial sleep deprivation, whereas that of plasma prolactin was higher (P < 0.05) during the trial after an early awakening. Plasma cortisol was lower (P < 0.05) during recovery after both sleep deprivation conditions. Blood lactate was higher (P < 0.05) during submaximal exercise performed after both a delayed bedtime and an early awakening. Zolpidem-induced sleep did not affect the hormonal and metabolic responses to subsequent exercise. Our results demonstrate only minor alterations in the hormonal responses to exercise after partial sleep deprivation.  相似文献   
3.
Sports characterized by little or moderate weight bearing or impact have a low osteogenic effect. However, the action of such sports on bone turnover remains unclear. The objective of this study was to determine the effect on bone remodelling of physical activities that induce moderate external loading on the skeleton. Thirty-eight male athletes aged 18–39 years (cyclists, n?=?11; swimmers, n?=?13; triathletes, n?=?14) and 10 age-matched sedentary controls aged 22–35 years participated in the study. The study combined measurement of bone mineral density by dual-energy X-ray absorptiometry and bone turnover assessment from specific biochemical markers: serum bone-specific alkaline phosphatase, osteocalcin, urinary type I collagen C-telopeptide and calcium. Compared with the controls and swimmers, adjusted bone mineral density was higher (P?<?0.05) in triathletes at the total proximal femur and lower limbs. No differences in bone mineral density were found between cyclists, swimmers and controls. Compared with controls, osteocalcin was higher (P?<?0.05) in triathletes and swimmers and urinary type I collagen C-telopeptide was higher in swimmers only. Serum bone-specific alkaline phosphatase was lower (P?<?0.05) in cyclists than in all other groups. In conclusion, an osteogenic effect was found only in triathletes, mainly at bone sites under high mechanical stress. Bone turnover differed in athletes compared with controls, suggesting that bone turnover may be sport-practice dependent. Despite some encouraging observations, it was not possible to show that changes in the bone remodelling process were sport-discipline dependent.  相似文献   
4.
《野草》主题的佛学解读   总被引:2,自引:0,他引:2  
《野草》主题隐含着一个与佛学苦、空观相吻合的逻辑层次。在现世苦难的打击下,鲁迅常常觉得唯“黑暗与虚无”乃是“实有”,佛学无常无我价值观促使他走向“绝望之为虚妄,正与希望相同”的空无状态。由空开拓出生命的抗争之路,承担起现世世界扫滞除执、反抗绝望的责任是《野草》哲学的关键。诗文吸收佛教勇猛精进的精神,同时消解了佛教因果轮回的唯心思想。  相似文献   
5.
This contribution considers a variety of aspects of the bloodstock breeding world during the three decades following World War Two, focusing in particular on the breeders of thoroughbred horses and the attitudes of those breeders towards their calling. It is argued that even at this late stage of its history, the persistence of the Corinthian amateur ideal, a dogged indifference to the realities of social and economic change, and a high degree of institutional social exclusiveness was in part responsible for the relative decline of what had been, in the inter-war years, the world's pre-eminent bloodstock industry.  相似文献   
6.
自“日本学生学习能力降低了”这一问题提出以来,日本社会各界对实施学力调查的目的、方法等提出了质疑。基于真实性评价的观点,实施学力调查需要慎重考虑诸如学力模式、学力结构以及学力调查的社会环境等多种因素。通过比较分析可以看到,尽管“TIMSS2003”、“PISA2003”和“国研调查2003”三次学力调查所设计的学力模式有所不同,但都是为了更好地实现真实性评价目标进行的创新性尝试。究竟何种学力调查能更好地体现真实性评价,还需要在教育实践中进一步探索。  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号