Nutrition for the young athlete

Athletics is a popular sport among young people. To maintain health and optimize growth and athletic performance, young athletes need to consume an appropriate diet. Unfortunately, the dietary intake of many young athletes follows population trends rather than public health or sports nutrition recommendations. To optimize performance in some disciplines, young athletes may strive to achieve a lower body weight or body fat content and this may increase their risk for delayed growth and maturation, amenorrhoea, reduced bone density, and eating disorders. Although many of the sports nutrition principles identified for adults are similar to those for young athletes, there are some important differences. These include a higher metabolic cost of locomotion and preferential fat oxidation in young athletes during exercise. Young athletes, particularity children, are at a thermoregulatory disadvantage due to a higher surface area to weight ratio, a slower acclimatization, and lower sweating rate. An appropriate dietary intake rather than use of supplements (except when clinically indicated) is recommended to ensure young athletes participate fully and safely in athletics.     

The Poverty of Constructivism

Constructivism claims to be a postepistemology that replaces 'traditional' concepts of knowledge. Supporters of constructivism have argued that progress requires that pre-service teachers be weaned off traditional approaches and that they should adopt constructivist views of knowledge. Constructivism appears to be gaining ground rapidly and should no longer be viewed as an exercise in radical thinking primarily aimed at generating innovative teaching. It has become an integral part of the pedagogic mainstream. Close examination of the theoretical foundations of constructivism, however, reveals that the basic assumptions of constructivism are flawed. Far from being a postepistemology, constructivism simply regresses to a pre-Renaissance mindset with theology replaced with a psychologism. Constructivists should be aware that the implications of constructivism for future generations may be both profound and non-benign.     

第9届世界健美操锦标赛男子单项决赛难度动作位序分析

运用图像分析、文献资料调研、数理统计等研究方法,对第9届世界健美操男子单项决赛前8名运动员难度动作出现的位序与成绩关系进行分析。研究显示,成套难度动作位序布局的合理性、难度动作类别创编的均衡性与运动成绩呈正相关;难度动作的选择应与运动员的实际身体素质水平和专业技术水平相吻合,难度动作才能完成得轻松优美,才能充分展现男子单项目运动员的个性化特点,“难”与“美”的结合仍然是当今健美操制胜的关键。     

“家庭—社区—医院—高校”四位一体运动健康促进模式探索

摘要：在理论分析基础上,运用试验、数理统计等方法,建立以居民为核心,以家庭和社区为基本环境,以预防为主,整合社区、医院和高校的优质资源,使家庭、社区居民、健康促进团队以及研究者之间形成一种伙伴关系,共同解决慢性疾病问题的“家庭—社区—医院—高校”四位一体运动健康促进模式,并在运动及膳食干预糖尿病前期非酒精性脂肪肝项目实施过程中运用该模式进行管理运作,完成该模式的可行性验证和丰富完善。研究结果表明本运动健康促进模式在实施过程中运行良好,帮助慢性疾病患者建立健康生活方式,改善疾病状况和生活质量,并得到患者的好评,可以有效地应用于社区慢病预防控制。本文对该模式的组织架构、管理流程和运行机制进行详细描述及分析论证,旨在为构建以社区为基础的科学有效的新型城市慢病管理的服务体系提供一定理论和实践借鉴参考。     

Validation of two accelerometers to determine mechanical loading of physical activities in children

The purpose of this study was to assess the validity of accelerometers using force plates (i.e., ground reaction force (GRF)) during the performance of different tasks of daily physical activity in children. Thirteen children (10.1 (range 5.4–15.7) years, 3 girls) wore two accelerometers (ActiGraph GT3X+ (ACT), GENEA (GEN)) at the hip that provide raw acceleration signals at 100 Hz. Participants completed different tasks (walking, jogging, running, landings from boxes of different height, rope skipping, dancing) on a force plate. GRF was collected for one step per trial (10 trials) for ambulatory movements and for all landings (10 trials), rope skips and dance procedures. Accelerometer outputs as peak loading (g) per activity were averaged. ANOVA, correlation analyses and Bland–Altman plots were computed to determine validity of accelerometers using GRF. There was a main effect of task with increasing acceleration values in tasks with increasing locomotion speed and landing height (P < 0.001). Data from ACT and GEN correlated with GRF (r = 0.90 and 0.89, respectively) and between each other (r = 0.98), but both accelerometers consistently overestimated GRF. The new generation of accelerometer models that allow raw signal detection are reasonably accurate to measure impact loading of bone in children, although they systematically overestimate GRF.