Demographic characteristics of elite Kenyan endurance runners

Abstract

Kenyan athletes have dominated international distance running in recent years. Explanations for their success include favourable physiological characteristics, which could include favourable genetic endowment, and advantageous environmental conditions. The aim of this study was to compare the demographic characteristics of elite Kenyan runners with those of the general Kenyan population. Questionnaires, administered to 404 elite Kenyan runners specializing in distances ranging from the 800 m to the marathon and 87 Kenyan controls, obtained information on place of birth, language, and distance and method of travel to school. Athletes were separated into two groups according to athletic success: those who competed in international competition and those who competed in national competition. The athletes differed from controls in regional distribution, language, and distance and method of travel to school; athletes also differed from each other with the exception of method of travel to school. Most national and international athletes came from the Rift Valley province (controls 20%, national athletes 65%, international athletes 81%), belonged to the Kalenjin ethnic group (controls 8%, national athletes 49%, international athletes 76%) and Nandi sub-tribe (controls 5%, national athletes 25%, international athletes 44%), and spoke languages of Nilotic origin (controls 21%, national athletes 60%, international athletes 79%). A higher proportion of all athletes ran to school each day (controls 22%, national athletes 73%, international athletes 81%) and covered greater distances. In conclusion, Kenyan runners are from a distinctive environmental background in terms of geographical distribution, ethnicity and travelled further to school, mostly by running. These findings highlight the importance of environmental and social factors in the success of Kenyan runners.     

Nutritional strategies to optimize training and racing in middle-distance athletes

Middle-distance athletes implement a dynamic continuum in training volume, duration, and intensity that utilizes all energy-producing pathways and muscle fibre types. At the centre of this periodized training regimen should be a periodized nutritional approach that takes into account acute and seasonal nutritional needs induced by specific training and competition loads. The majority of a middle-distance athlete's training and racing is dependant upon carbohydrate-derived energy provision. Thus, to support this training and racing intensity, a high carbohydrate intake should be targeted. The required energy expenditure throughout each training phase varies significantly, and thus the total energy intake should also vary accordingly to better maintain an ideal body composition. Optimizing acute recovery is highly dependant upon the immediate consumption of carbohydrate to maximize glycogen resynthesis rates. To optimize longer-term recovery, protein in conjunction with carbohydrate should be consumed. Supplementation of beta-alanine or sodium bicarbonate has been shown to augment intra- and extracellular buffering capacities, which may lead to a small performance increase. Future studies should aim to alter specific exercise (resistance vs. endurance) and/or nutrition stimuli and measure downstream effects at multiple levels that include gene and molecular signalling pathways, leading to muscle protein synthesis, that result in optimized phenotypic adaptation and performance.     

丹尼尔论远程教育基础(下)

该文考查了远程教育的基础,它的发展历史和它赖以发展进化的技术。历史上有两种传统的远程教育:远程课堂教学和函授教学。它们具有不同的教育学特征和成本结构。然而,新一代技术即知识媒体,作为计算机技术、电子通信技术和认知科学汇同结合的产物,正在将远程教育的两大传统结合在一起。知识媒体将通过进一步发展远程教育对大学的革新作出重大贡献。     

Demographic characteristics of elite Kenyan endurance runners

Kenyan athletes have dominated international distance running in recent years. Explanations for their success include favourable physiological characteristics, which could include favourable genetic endowment, and advantageous environmental conditions. The aim of this study was to compare the demographic characteristics of elite Kenyan runners with those of the general Kenyan population. Questionnaires, administered to 404 elite Kenyan runners specializing in distances ranging from the 800 m to the marathon and 87 Kenyan controls, obtained information on place of birth, language, and distance and method of travel to school. Athletes were separated into two groups according to athletic success: those who competed in international competition and those who competed in national competition. The athletes differed from controls in regional distribution, language, and distance and method of travel to school; athletes also differed from each other with the exception of method of travel to school. Most national and international athletes came from the Rift Valley province (controls 20%, national athletes 65%, international athletes 81%), belonged to the Kalenjin ethnic group (controls 8%, national athletes 49%, international athletes 76%) and Nandi sub-tribe (controls 5%, national athletes 25%, international athletes 44%), and spoke languages of Nilotic origin (controls 21%, national athletes 60%, international athletes 79%). A higher proportion of all athletes ran to school each day (controls 22%, national athletes 73%, international athletes 81%) and covered greater distances. In conclusion, Kenyan runners are from a distinctive environmental background in terms of geographical distribution, ethnicity and travelled further to school, mostly by running. These findings highlight the importance of environmental and social factors in the success of Kenyan runners.     

丹尼尔论远程教育基础(上)

该文考查了远程教育的基础,它的发展历史和它赖以发展进化的技术。历史上有两种传统的远程教育:远程课堂教学和函授教学。它们具有不同的教育学特征和成本结构。然而,新一代技术即知识媒体,作为计算机技术、电子通信技术和认知科学汇同结合的产物,正在将远程教育的两大传统结合在一起。知识媒体将通过进一步发展远程教育对大学的革新作出重大贡献。     

Representational guidance and student engagement: examining designs for collaboration in online synchronous environments

In this paper we report the results of a study which investigated the affordances of multi-user virtual environments (MUVEs) for collaborative learning from a design perspective. Utilizing a mixed methods approach, we conducted a comparative study of the effect of varying representational and interactional design features on a collaborative design activity in three online synchronous environments. We compared environments featuring multiple modes of interaction (MUVEs), shared representations (text chat and 2D still images) and text-only features. Sixty-one students enrolled in an undergraduate course on Child Development participated in the study. Participants were asked to design a theoretically-based, developmentally appropriate, preschool classroom setting. Students were randomly assigned to one of three online learning environments that provided varying levels of representation and interaction. Significant differences in collaborative problem solving interactions were found. Participants in the shared representations + text condition evidenced stronger learning outcomes as regards substantive discussion and integration of child development concepts; while participants in the MUVE condition reported the most enjoyment with the experience. These findings are explained by the concepts of representational guidance, representational bias, educational affordances and interface design metaphors. Suggestions for the design of MUVEs for collaborative learning are provided.     

Engaging in Interactive Book Reading: Experiences of Refugee Mother–Child Dyads

Early Childhood Education Journal - Interactive book reading is an active practice that aims to stimulate children’s language and literacy development. The interactions that take place during...