Leisure time physical activity in Australian women: relationship with well being and symptoms

This paper explores the association between moderate levels of physical activity (PA) and health benefits in well being and symptoms such as tiredness, back pain, and constipation. Participants in the Australian Longitudinal Study on Women's Health, 14,502 young women (ages 18-23 years), 13,609 middle-age women (45-50 years), and 11,421 older women (ages 70-75 years), answered questions about vigorous and less vigorous exercise (used to determine a physical activity score), well being (SF-36), symptoms, and medical conditions. There were significant associations between the PA score and SF-36 in each cohort. Odds ratios (OR) for a range of symptoms and conditions were lower for women who reported low to moderate activity than for sedentary women, for example, for young women or for constipation = 0.76 (CI, 0.65-0.89), for middle-age women or for tiredness = 0.70 (0.63-0.78). There was no threshold of PA at which health benefits increased significantly. Although cross-sectional, the findings suggest that low-to-moderate levels of exercise are associated with a range of health benefits for women of all ages. These preliminary findings will be followed up during the longitudinal study.     

美国数学教学问题一束

众所周知,当前美国数学教学的主要趋势是“问题解决”(Problem Solving)。这里的一些“问题”在美国是比较常见的。有些在国内也经常碰到,但课堂上用得不多,从培养学生的创造性数学思维来看,这些问题会具有一定的价值。——编者     

摄影和摄象技术三维直接线性变换(DLT)再现精度的比较

记录人体运动的准确性在很大程度上取决于记录方法的精确度。计算出的物体运动学的数值,主要依赖对物体运动记录的准确性。人体运动的生物力学分析经常需要对16mm摄影或摄象技术记录的内容进行分析.由于摄象具有成本低,使用方便,处理时间短的特点,使摄象技术比摄影更具吸引力.然而必须考虑摄象精确度是否与摄影标准相同.要使摄象技术合法地进入人体运动分析领域,摄象记录的精度必须达到摄影记录的     

学校体育课的内容(续二)

3.怎样确定教学计划中的身体练习制定教学计划的一项要求是,由大量的身体练习中选择对教学需要和适合的身体练习。这就需要有可靠的根据,不然就没有科学的准则,就会带有偶然性和主观主义。在体育课教学法中,以及在其他课程的教学理论和教学法中,直到目前对怎样选择教材都还很少进行科学研究。目前在拟     

重视出发和转身的改进

竞速游泳是争分夺秒的项目,在今天的实际竞赛中,百分之一秒就足以判定夺标先后.分析一下竞赛成绩的构成,不外出发、转身和途中配合游几部分,而出发和转身的时间在决定竞赛成绩上有着举足轻重的作用。科学地判定出发和转身的时间要兼顾技术和距离两个因素,这个距离还应考虑项目的差异。本文提出的测定距离正是如此。我们认为这个测定距离是可取的,而我国的测定距离,如在“1984年上海国际游泳邀请赛调研报告”一文中采用的是值得商榷的,因为距离过短就不能包括出发、转身动作;距离过长又包括了途中配合游的时间。都造成测定的失真.采用统一的、科学的测定出发、转身距离,不但可以准确地测定出发、转身时间,而且便于分析比较。盲目地、无根据地说某一运动员游得慢,不如准确地指出“慢”在哪里,这就需要科学的测量,给运动员提供正确的反馈信息。提高游泳成绩首先来源于对游泳技术某一环节的重要性的认识。