Muscle Fiber Type Composition and Knee Extension Isometric Strength Fatigue Patterns in Power- and Endurance-Trained Males

Abstract

Muscle fiber type composition in the vastus lateralis and knee extension isometric strength fatigue patterns were assessed in eight endurance-trained and eight power-trained males. Two different 25-trial isometric contraction exercise regimens were administered: a 10-second contraction, 5-second intertrial rest condition designed to induce a fast rate of fatigue and a 10-second contraction, 20-second intertrial rest condition designed to induce a slower rate of fatigue. The power group fatigued almost four times faster than the endurance group in the 10:5 exercise condition. In the 10:20 exercise condition, the endurance group showed no fatigue pattern while the power group had a significant strength decrement of 32%. In both exercise conditions, the power group exhibited more complex fatigue patterns in terms of statistically significant trend components. Maximum isometric strength correlated positively with slow twitch (ST) percent number in power (r = .80) and endurance (r = .48) groups, but negatively with linear trend coefficients in endurance (r = -.62) and power (r = -.80) groups. Maximum isometric strength also correlated higher with fatigue curve trend coefficients than did muscle fiber type composition. Thus, a faster rate of fatigue was associated with higher maximum isometric strength and with higher ST percent number and area. Since maximum isometric strength correlated with body weight (r = .86 for groups combined), both maximum isometric strength and muscle mass appear to be more important determinants of knee extension isometric strength fatigue patterns than muscle fiber type composition.     

成年人身体活动变化阶段及其社会心理学相关因素——初步检验“从无活动到保持活动的四步骤(FIT)”模型

基于锻炼心理学领域中的“从无活动到保持活动的四步骤模型”(Four Steps from Inactivity to Ac-tivity; FIT模型),以1 206名成年人为研究对象,通过横断性研究考查了6个身体活动变化阶段与10个社会心理学相关变量之间的关系.研究结果表明,被试在身体活动阶段上的分布为:前考虑期147(12.2％),考虑期273(22.6％),准备期148(12.3％),探索期144(11.9％),波动期201(16.7％)和保持期293(24.3％).有关社会心理学相关变量在相邻阶段间的配对比较,37项假设关系中的22项得到了支持,假设符合率为59.5％.进一步回归分析表明,性别、受教育程度、主观障碍、自我效能、情感态度和社会支持共同解释了阶段方差变异的32.6％.该研究初步验证了FIT模型所涉及的重要社会心理学相关因素与身体活动变化阶段之间的相关关系,基本支持了FIT模型的理论建构.     

Language Across a Curriculum of Teacher Training: an instance of course development

This paper describes the ways in which the relationship between teaching and learning in schools, and pupil and teacher language, are explored by students and staff in the different elements of a one‐year postgraduate initial training course for Secondary teachers. It deals with how the staff of a quite large department attempt to keep the theoretical and practical expressions of the topic together by monitoring the manner in which the elements of the whole course structure interact.     

The educational psychologist as instructional designer

Educational psychology, as an academic discipline, needs a model or paradigm for conceptualizing and solving educational problems. The systems approach to instructional design is proposed as a unifying process which was developed primarily by educational psychologists and has wide applicability in education. The use of the systems approach is advocated because (1) it provides a method for delivering effective service, (2) it incorporates many concepts presently familiar to educational psychologists and suggests other topics which should be of concern, (3) it suggests a wide array of research and evaluation problems, and (4) it provides an integrative framework for the design of graduate training programs. These four factors are discussed in detail.     

Juvenile picture books about the Holocaust: Extending the definitions of children’s literature

Despite a variety of definitions, children’s books and picture books generally adhere to certain conventions. Depicting the Holocaust in children’s books challenges these conventions. The authors review the Holocaust literature for children, paying special attention to two picture books: Let the Celebrations Begin! by Margaret Wild and Julie Vivas, and Rose Blanche by Roberto Innocenti and Christophe Gallaz. Their analysis leads them to conclude the books for children that deal with horrific events should be viewed as a category of their own. Virginia A. Walter is an assistant professor at the Graduate School of Library and Information Science at the University of California, Los Angeles. She has a Master of Library Science degree from the University of California, Berkeley, and a Ph.D. from the University of Southern California. Susan F. March is on the faculty of Kehillath Israel Religious School in Pacific Palisades, California. She has a Master of Arts in Education degree from the University of Judaism in Los Angeles and a Master of Library Science from UCLA.