Considerations for protein intake in managing weight loss in athletes     

Caoileann H. Murphy  Amy J. Hector 《European Journal of Sport Science》2015,15(1):21-28

Abstract

A large body of evidence now shows that higher protein intakes (2–3 times the protein Recommended Dietary Allowance (RDA) of 0.8 g/kg/d) during periods of energy restriction can enhance fat-free mass (FFM) preservation, particularly when combined with exercise. The mechanisms underpinning the FFM-sparing effect of higher protein diets remain to be fully elucidated but may relate to the maintenance of the anabolic sensitivity of skeletal muscle to protein ingestion. From a practical point of view, athletes aiming to reduce fat mass and preserve FFM should be advised to consume protein intakes in the range of ～1.8–2.7 g kg^?1 d^?1 (or ～2.3–3.1 g kg^?1 FFM) in combination with a moderate energy deficit (?500 kcal) and the performance of some form of resistance exercise. The target level of protein intake within this recommended range requires consideration of a number of case-specific factors including the athlete's body composition, habitual protein intake and broader nutrition goals. Athletes should focus on consuming high-quality protein sources, aiming to consume protein feedings evenly spaced throughout the day. Post-exercise consumption of 0.25–0.3 g protein meal^?1 from protein sources with high leucine content and rapid digestion kinetics (i.e. whey protein) is recommended to optimise exercise-induced muscle protein synthesis. When protein is consumed as part of a mixed macronutrient meal and/or before bed slightly higher protein doses may be optimal.  相似文献   

广义Boussinesq方程的KAM环面(英文)     

石艳玲  陆雪竹 《东南大学学报》2015,31(1):157-162

考虑周期边界下具有非线性项f(u)=u3的一维广义Boussinesq方程u tt-u xx+(f(u)+u xx)xx=0.首先,将上述方程转化为一个哈密顿系统,并将该系统在线性算子的特征基上展开得到坐标形式下的哈密顿系统.鉴于切频与法频之间复杂的共振关系,考虑一类具有特殊结构的拟周期解.其次,验证了哈密顿向量场的正则性,并对四次项进行规范化,从规范形中可以得到无穷维KAM定理所要求的非退化和非共振条件.利用一个KAM定理证明与方程等价的无穷维哈密顿系统存在许多有限维不变环面,故原方程有许多小振幅的拟周期解.  相似文献   

The academic writing process in Spanish universities: perceptions of students and faculty / El proceso de escritura académica en la universidad española: percepciones de estudiantes y profesores     

Javier Marín  Sonia López  Julio Roca-De-Larios 《Cultura y Educación》2015,27(3):504-533

Abstract

This paper is intended as an exploration of university faculty and students’ perceptions of a number of dimensions involved in the written composition of academic texts. We analysed the responses to scale 3 in the European Writing Survey (EUWRIT) (in its Spanish version: Encuesta Europea sobre la Escritura Académica, EEEA) by a group of social science and humanities students (n = 1,030) and faculty (n = 230) from nine Spanish universities. We then examined the similarities and differences in their perceptions and established a factorial structure of the different dimensions underlying the writing process. The data indicate that both groups concur in the value assigned to both changing ideas in the course of the composition process (although this process seems to be understood differently by each group) and the revision and feedback processes. The students, however, claim to be involved in more planning and previous reading activities than the teachers perceive them to be. The significance of these results for a process-oriented perspective in academic writing is discussed.  相似文献   

新形势下辅导员角色定位的困境及解决路径     

李伟弟 《九江职业技术学院学报》2015,(1)

《高等学校辅导员职业能力标准（暂行）》对辅导员职业能力进行了明确规定,对辅导员今后角色定位与发展路径提出了新要求。本文结合《标准》内容,从新形势下辅导员角色定位的现实困境和发展瓶颈入手,分析了相关问题的内在原因,并对解决问题的路径做出研究和思考。  相似文献   

基于劳伦兹系统的交通模型近似解     

冯煜杰  楼特艳  陈晨  崔莉佳  钟华  韩祥临 《湖州师范学院学报》2015,(4):1-5

通过代换,将基于劳伦兹系统构建的交通流方程组转换成非线性方程,分别利用匹配渐近法和同伦分析法研究非线性交通模型,讨论当参数σ= t n/t v ?1时的新情况,得到非线性方程的两种解析近似解,为分析车头变化情况提供理论依据。  相似文献   

眼界决定境界思路决定出路--中考历史复习策略     

袁翠娟 《科教文汇》2015,(21)

本文针对中考的命题规律,提出复习的方向和策略,以便老师指导学生复习应考。分别从考纲分析研读和复习注意事项两个方面来分析指导。  相似文献   

重积分微分方程重叠型稳定解估计算法     

李友国 《科技通报》2015,(6)

结合重积分微分方程的稳定性理论,得知重积分微分方程中多复变微分方程的初值解不一定可逆,使用近似矩阵进行渐进逼近,根据自相关函数信息矢量迭代模型,得到当自相关向量的最小互信息量达到渐进稳定,求解双边界条件下的稳定性平衡点,实现全局渐进稳定,在重积分微分方程中对多复变微分方程进行时空分叉问题的分析和初值解的稳定性和收敛性分析,通过数学推导和数值分析,得出重积分微分方程重叠型稳定解存在,且具有收敛性。  相似文献   

“李约瑟难题”的求解与消解进路探析     

智广元 《科技管理研究》2015,(23)

通过对国内外"李约瑟难题"研究文献的系统梳理,以求解进路与消解进路为问题取向,从科学技术发展的内史进路、外史进路与综合史进路的视角探讨问题的求解取向,从逻辑进路、科学进路或技术进路视角探讨问题的消解取向。据此,该难题的综合史进路是问题求解取向的较好选择,而问题消解取向实质上是坚持了文化相对主义或者否认了难题的基本预设。  相似文献   

Physical profiles of elite,sub-elite,regional and age-group netballers     

Marni J. Simpson  David G. Jenkins  Michael D. Leveritt  Vincent G. Kelly 《Journal of sports sciences》2019,37(11):1212-1219

Physical profile data from elite, sub-elite, regional, under 21s (U21), under 19s (U19) and under 17s (U17) (n = 845) players from a state netball association in Australia were analysed. Within season changes were examined for the elite and sub-elite players. Longitudinal changes were examined for the elite across four consecutive netball seasons.

Elite were significantly older (24.3 ± 3.4years), taller (182.4 ± 7.2cm) and heavier (73.42 ± 6.95kg) than other playing levels (p < 0.001, ES 0.49–3.26) and had higher vertical jump (VJ) data compared to all groups (p < 0.001, ES 0.47–0.93). U17’s were significantly faster than elite, sub-elite and U19 players over 5m (p < 0.05, ES 0.36–0.58) while elite were faster over 20m compared to all groups (p < 0.01, ES 0.45–0.72). Elite achieved a greater distance (1350.8m; p < 0.05, ES 0.32–0.50) in the Yo-YoIRT1 compared to the sub-elite, regional, U19 and U17. VJ height significantly increased from the 2014 (51.6 ± 4.8cm) to the 2017 season (59.6 ± 6.3cm) for the elite players (p < 0.01, ES 1.18). Yo-YoIRT1 test scores increased significantly between the pre-season and in-season phases (p < 0.05, ES 0.17).  相似文献   

Coeducational and single-sex physical education: students’ situational interest in learning tasks centred on technical skills     

Vanessa Lentillon-Kaestner  Cédric Roure 《Physical Education & Sport Pedagogy》2019,24(3):287-300

Background: A student’s choice to engage in a learning task is highly related to the student’s environmental stimuli and his or her perception of interest. From this perspective, the construct of situational interest (SI) has been used to interpret students’ motivation in task engagement. SI is assumed to be transitory, environmentally activated, and context specific. It has been conceptualized as a multidimensional construct with five dimensions: instant enjoyment, exploration intention, attention demand, novelty, and challenge. Few prior studies have compared SI between girls and boys in physical education (PE) contexts, and these studies have offered contrasting findings. They were conducted in coeducational (coed) or single-sex contexts and used learning tasks centred on a variety of outcomes: technical or tactical skills, creativity and cultural understanding.

Purpose: In the context of the debate on single-sex and coed classes in PE, this study aimed to estimate the effects of single-sex and coed PE classes on students’ situational interest (SI) within learning tasks centred on technical skills. The researchers decided to study learning tasks centred on the development of students’ technical skills, since these tasks are often used by teachers in PE.

Participants: The sample consisted of 177 Swiss secondary school students, aged 11–17 years (M?=?14.07, SD?=?1.41, 96 boys, 81 girls).

Data collection: The students completed the French 15-item SI Scale after practising a technical learning task in single-sex and coed PE contexts. The researchers chose five physical activities (i.e. athletics, basketball, dance, gymnastics, and volleyball), which are commonly taught in the state of Vaud (Switzerland) and provide a balance between masculine and feminine activities.

Data analysis: A two-way repeated-measures MANOVA was performed to examine the main and interaction effects of student sex and class sex composition on the five SI dimensions.

Findings: The results showed a main effect of class sex composition on student SI but no main effect of student sex and no interaction effect of student sex and class sex composition. More precisely, the scores for three SI dimensions (i.e. instant enjoyment, exploration intention, and attention demand) were higher in the coed context than in the single-sex context.

Conclusions: This study encourages teachers to propose coed PE classes to enhance students’ motivation and engagement when practising learning tasks centred on technical skills. This study offers supplementary evidence of the teacher’s role in promoting student SI. Beyond accounting for students’ dispositional factors (e.g. sex), PE teachers can significantly impact students’ SI in technical learning tasks through instructional choices.  相似文献