Effect of carbohydrate ingestion during cycling exercise on affective valence and activation in recreational exercisers

Carbohydrate (CHO) ingestion enhances “feel-good” responses during acute exercise but no study has examined the effect of regular ingestion of CHO on affective valence. We investigated the effect of CHO ingestion on perceptual responses and perceived work intensity of individual exercise sessions throughout a 10-week cycling (“spin”) exercise intervention. We also assessed whether any changes in affect and/or perceived work intensity would influence health and fitness parameters. Twelve recreational exercisers (46 ± 9 years; nine females and three males) were randomly allocated to either CHO (7.5% CHO; 5 mL · kg^?1 per exercise session; n = 6; CHO) or placebo (0% CHO, taste- and volume-matched solution; n = 6; PLA) groups. Participants exercised 2 × 45-min per week, over a 10-week intervention period. Perceptual measures of exertion (RPE), affect (feeling scale, FS) and activation (felt arousal scale, FAS) were assessed after each exercise session. The FAS ratings increased over time in CHO but decreased throughout the intervention in PLA (P = 0.03). There were no differences in heart rate (P = 0.70), RPE (P = 0.05) and FS (P = 0.84) between trials. Furthermore, no changes in health and fitness parameters were observed over time or between groups. CHO ingestion enhanced ratings of activation in recreational exercisers throughout a 10-week cycling intervention.     

Fluid ingestion and exercise hyperthermia: Implications for performance,thermoregulation, metabolism and the development of fatigue

The development of fatigue during exercise and the subsequent onset of exhaustion occur earlier in the heat than in cooler environments. The underlying mechanisms responsible for the premature development of fatigue in the heat have yet to be clearly identified. However, the proposed mechanisms include metabolic, cardiovascular and central nervous system perturbations, together with an elevated core temperature. Fluid ingestion is one of three strategies that have been shown to be successful in enhancing the performance of endurance exercise in the heat, with the other interventions being precooling and acclimatization. However, like the development of fatigue in the heat, the mechanisms by which fluid ingestion allows for improved exercise performance remain unclear. We propose that fluid ingestion enhances exercise performance in the heat by increasing the heat storage capacity of the body. We suggest that the thermoregulatory, metabolic and cardiovascular alterations that occur as a result of this increased heat storage capacity contribute to performance enhancement when fluid is ingested during exercise heat stress.     

Creatine supplementation does not decrease oxidative stress and inflammation in skeletal muscle after eccentric exercise

Abstract

Thirty-six male rats were used; divided into 6 groups (n = 6): saline; creatine (Cr); eccentric exercise (EE) plus saline 24 h (saline + 24 h); eccentric exercise plus Cr 24 h (Cr + 24 h); eccentric exercise plus saline 48 h (saline + 48 h); and eccentric exercise plus Cr 48 h (Cr + 48h). Cr supplementation was administered as a solution of 300 mg · kg body weight^?1 · day^?1 in 1 mL water, for two weeks, before the eccentric exercise. The animals were submitted to one downhill run session at 1.0 km · h^?1 until exhaustion. Twenty-four and forty-eight hours after the exercise, the animals were killed, and the quadriceps were removed. Creatine kinase levels, superoxide production, thiobarbituric acid reactive substances (TBARS) level, carbonyl content, total thiol content, superoxide dismutase, catalase, glutathione peroxidase, interleukin-1b (IL-1β), nuclear factor kappa B (NF-kb), and tumour necrosis factor (TNF) were analysed. Cr supplementation neither decreases Cr kinase, superoxide production, lipoperoxidation, carbonylation, total thiol, IL-1β, NF-kb, or TNF nor alters the enzyme activity of superoxide dismutase, catalase, and glutathione peroxides in relation to the saline group, respectively (P < 0.05). There are positive correlations between Cr kinase and TBARS and TNF-α 48 hours after eccentric exercise. The present study suggests that Cr supplementation does not decrease oxidative stress and inflammation after eccentric contraction.     

Factors contributing to mathematical problem-solving performance: An exploratory study

This paper describes differences in mathematical problem-solving performance of third-grade gifted and fifth-grade average students observed during an eight week period. Results indicated that such factors as attitude, motivation, and belief systems were important to performance. In addition there were major differences in problem-solving behavior between the girls and boys in this study. Because these results were incidental to the original questions of the study (Buchanan, 1984), they were deemed especially significant. Four groups, one of third-grade gifted boys, one of third-grade gifted girls, one of average boys and one of fifth-grade average girls met with the experimenter twice a week for eight weeks to solve a variety of mathematical problems. In the global analysis of video tapes of all sessions and post hoc statistical analysis of selected quantifiable variables, differences in problem-solving performance were best described in terms of motivation, beliefs about mathematics, problem-solving strategies, and means of achieving satisfaction. In addition, the girls' groups were more ego-involved and social; they completed fewer problems and had longer solution times than the boys' groups. Further holistic research is needed to describe the complex interaction that occurs during mathematical problem solving in group situations. Then, appropriate intervention might be designed to assure that both boys and girls have an opportunity to perform at optimum levels.     

Research on Social Integration: What Are The Problems?

THIS LIMITED REVIEW of research on the social integration of children with disabilities in mainstreaming programs showed that there are several factors which may explain the apparent inconsistencies within the research literature. The diverse groups of individuals involved necessitate that attention be paid to pertinent variables and that care must be taken when findings are generalized to other groups of children with disabilities. An issue of particular concern was the simplistic measuring techniques employed in some research, particularly where studies relied on a single technique such as sociometry. There is limited evidence to support the increased use of multivariate statistical procedures as a means of producing more consistent findings. While most studies reviewed did not incorporate special treatments, that is other than integrated settings, invariably such treatments produced positive outcomes. Studies involving research designs which used the social acceptance of normal children as the basis for assessing social integration frequently resulted in negative findings.     

Teachers' learning to facilitate high‐level student thinking: Impact of a video‐based professional development

Attaining the vision for science teaching and learning emphasized in the Framework for K‐12 Science Education and the next generation science standards (NGSS) will require major shifts in teaching practices in many science classrooms. As NGSS‐inspired cognitively demanding tasks begin to appear in more and more science classrooms, facilitating students' engagement in high‐level thinking as they work on these tasks will become an increasingly important instructional challenge to address. This study reports findings from a video‐based professional development effort (i.e., professional development [PD] that use video‐clips of instruction as the main artifact of practice to support teacher learning) to support teachers' learning to select cognitively demanding tasks and to support students' learning during the enactment of these tasks in ways that are aligned with the NGSS vision. Particularly, we focused on the NGSS's charge to get students to make sense of and deeply think about scientific ideas as students try to explain phenomena. Analyses of teachers' pre‐ and post‐PD instruction indicate that PD‐participants began to adopt instructional practices associated with facilitating these kinds of student thinking in their own classrooms. The study has implications for the design of video‐based professional development for science teachers who are learning to facilitate the NGSS vision in science classrooms.     

Personal and Institutional Influences on Beginning Teachers’ Classroom Management Perspectives

The current investigation focused upon the changing perspectives of four young student teachers in their transition from university to secondary schools. Use was made of an interpretive inquiry method, including employing interviews and classroom observations for data collection.     

Student/Faculty Connections in the Development of Teaching

This project directly involved students in two different models of instructional development. The first model was a Student Consultant program in which faculty selected from a menu of instructional services carried out by students. Typical services included attending class as impartial observers, soliciting feedback from other students on their learning experiences, videotaping class sessions, and evaluating course Web sites. The second model of instructional development was a program of student‐assisted teaching seminars for college faculty. Student Associates helped serve as panelists and facilitators. Assessments of attitudes toward teaching indicated that faculty members viewed both professors and students as collaborators in the classroom as a result of the seminar series.     

Classroom Activities and Areas: Regularity of Use and Perceptions of Adaptability by General Early Educators

This report describes a mail survey of general early educators from Head Start, public school pre-kindergarten, public school kindergarten, and community preschool/child care programs. The purposes were to secure information about the availability of classroom activities and areas, and to obtain the respondents' perceptions of the ease with which activities and areas could be adapted to accommodate children with disabilities. Of the 893 mailed questionnaires, 483 (54.1%) were returned and coded. The respondents reportedly used a wide range of classroom activities and areas, and they rated those activities and areas as moderately easy to adapt. Also, respondents from mainstreamed programs used slightly more activities and perceived the activities as easier to adapt than did respondents from non-mainstreamed programs. The findings appear to indicate that placement of children with disabilities in segregated programs cannot be justified on grounds that integration will restrict the range of activities available to typically developing children, or on the grounds that the adaptations are perceived by program staff as too difficult to be accomplished.