Acute and long-term effects of exercise on appetite control: Is there any benefit for weight control?

Purpose of review: To examine the relationship between energy intake, appetite control and exercise, with particular reference to longer term exercise studies. This approach is necessary when exploring the benefits of exercise for weight control, as changes in body weight and energy intake are variable and reflect diversity in weight loss. Recent findings: Recent evidence indicates that longer term exercise is characterized by a highly variable response in eating behaviour. Individuals display susceptibility or resistance to exercise-induced weight loss, with changes in energy intake playing a key role in determining the degree of weight loss achieved. Marked differences in hunger and energy intake exist between those who are capable of tolerating periods of exercise-induced energy deficit, and those who are not. Exercise-induced weight loss can increase the orexigenic drive in the fasted state, but for some this is offset by improved postprandial satiety signalling. Summary: The biological and behavioural responses to acute and long-term exercise are highly variable, and these responses interact to determine the propensity for weight change. For some people, long-term exercise stimulates compensatory increases in energy intake that attenuate weight loss. However, favourable changes in body composition and health markers still exist in the absence of weight loss. The physiological mechanisms that confer susceptibility to compensatory overconsumption still need to be determined.

Low fat loss response after medium-term supervised exercise in obese is associated with exercise-induced increase in food reward

Objective: To examine exercise-induced changes in the reward value of food during medium-term supervised exercise in obese individuals. ---------- Subjects/Methods: The study was a 12-week supervised exercise intervention prescribed to expend 500 kcal/day, 5 d/week. 34 sedentary obese males and females were identified as responders (R) or non-responders (NR) to the intervention according to changes in body composition relative to measured energy expended during exercise. Food reward (ratings of liking and wanting, and relative preference by forced choice pairs) for an array of food images was assessed before and after an acute exercise bout. ---------- Results. 20 responders and 14 non-responders were identified. R lost 5.2 kg±2.4 of total fat mass and NR lost 1.7 kg±1.4. After acute exercise, liking for all foods increased in NR compared to no change in R. Furthermore, NR showed an increase in wanting and relative preference for high-fat sweet foods. These differences were independent of 12-weeks regular exercise and weight loss. ---------- Conclusion. Individuals who showed an immediate post-exercise increase in liking and increased wanting and preference for high-fat sweet foods displayed a smaller reduction in fat mass with exercise. For some individuals, exercise increases the reward value of food and diminishes the impact of exercise on fat loss.

Mentoring experiences as professional development for leaders in environmental education : the cascade of influence

Environmental education is a field which has only come of age since the late nineteen sixties. While its content and practice have been widely debated and researched, its leadership has been minimally studied and, therefore, is only partially understood. The role of mentoring in the development of leaders has been alluded to, but has attracted scant research. Therefore, this study explores the importance of mentoring during the personal and professional development of leaders in environmental education. Four major research questions were investigated. Firstly, have leaders been men to red during their involvement with environmental education? Secondly, when and how has that mentoring taken place? Thirdly, what was the personal and professional effectiveness of the mentoring relationship? Fourthly, is there any continuation of the mentoring process which might be appropriate for professional development within the field of environmental education? Leaders were solicited from a broad field of environmental educators including teachers, administrators, academics, natural resource personnel, business and community persons. They had to be recognized as active leaders across several environmental education networks. The research elicited qualitative and quantitative survey data from fifty seven persons in Queensland, Australia and Colorado, USA. Seventeen semi-structured interviews were subsequently conducted with selected leaders who had nominated their mentors. This led to a further thirteen 'linked interviews' with some of the mentors' mentors and new mentorees. The interview data is presented as four cases reflecting pairs, triads, chains and webs of relationships- a major finding of the research process. The analysis of the data from the interviews and the surveys was conducted according to a grounded theory approach and was facilitated by NUD.IST, a computer program for non-numerical text analysis. The findings of the study revealed many variations on the classical mentoring patterns found in the literature. Gender and age were not seen as mportant factors, as there were examples of contemporaries in age, older men to younger women, older women to younger men, and women to women. Personal compatibility, professional respect and philosophical congruence were critical. Mentoring was initiated from early, mid and late career stages with the average length of the relationship being fourteen years. There was seldom an example of the mentoree using the mentor for hierarchical career climbing, although frequent career changes were made. However, leadership actions were found to increase after the intervention of a mentoring relationship. Three major categories of informal mentoring were revealed - perceived,acknowledged and deliberate. Further analysis led to the evolution of the core concept, a 'cascade of influence'. The major finding of this study was that this sample of leaders, mentors and new mentorees moved from the perception of having been mentored to the acknowledgment of these relationships and an affirmation of their efficacy for both personal and professional growth. Hence, the participants were more likely to continue future mentoring, not as a serendipitous happening, but through a deliberate choice. Heightened awareness and more frequent 'cascading' of mentoring have positive implications for the professional development of future leaders in environmental education in both formal and informal settings. Effective mentoring in environmental education does not seek to create 'clones' of the mentors, but rather to foster the development of autonomous mentorees who share a philosophical grounding. It is a deliberate invitation to 'join the clan'.

The impact of outcomes-driven curriculum reform on teacher perspectives of professional practice

This thesis is the result of an investigation of a Queensland example of curriculum reform based on outcomes, a type of reform common to many parts of the world during the last decade. The purpose of the investigation was to determine the impact of outcomes on teacher perspectives of professional practice. The focus was chosen to permit investigation not only of changes in behaviour resulting from the reform but also of teachers' attitudes and beliefs developed during implementation. The study is based on qualitative methodology, chosen because of its suitability for the investigation of attitudes and perspectives. The study exploits the researcher's opportunities for prolonged, direct contact with groups of teachers through the selection of an over-arching ethnography approach, an approach designed to capture the holistic nature of the reform and to contextualise the data within a broad perspective. The selection of grounded theory as a basis for data analysis reflects the open nature of this inquiry and demonstrates the study's constructivist assumptions about the production of knowledge. The study also constitutes a multi-site case study by virtue of the choice of three individual school sites as objects to be studied and to form the basis of the report. Three primary school sites administered by Brisbane Catholic Education were chosen as the focus of data collection. Data were collected from three school sites as teachers engaged in the first year of implementation of Student Performance Standards, the Queensland version of English outcomes based on the current English syllabus. Teachers' experience of outcomes-driven curriculum reform was studied by means of group interviews conducted at individual school sites over a period of fourteen months, researcher observations and the collection of artefacts such as report cards. Analysis of data followed grounded theory guidelines based on a system of coding. Though classification systems were not generated prior to data analysis, the labelling of categories called on standard, non-idiosyncratic terminology and analytic frames and concepts from existing literature wherever practicable in order to permit possible comparisons with other related research. Data from school sites were examined individually and then combined to determine teacher understandings of the reform, changes that have been made to practice and teacher responses to these changes in terms of their perspectives of professionalism. Teachers in the study understood the reform as primarily an accountability mechanism. Though teachers demonstrated some acceptance of the intentions of the reform, their responses to its conceptualisation, supporting documentation and implications for changing work practices were generally characterised by reduced confidence, anger and frustration. Though the impact of outcomes-based curriculum reform must be interpreted through the inter-relationships of a broad range of elements which comprise teachers' work and their attitudes towards their work, it is proposed that the substantive findings of the study can be understood in terms of four broad themes. First, when the conceptual design of outcomes did not serve teachers' accountability requirements and outcomes were perceived to be expressed in unfamiliar technical language, most teachers in the study lost faith in the value of the reform and lost confidence in their own abilities to understand or implement it. Second, this reduction of confidence was intensified when the scope of outcomes was outside the scope of the teachers' existing curriculum and assessment planning and teachers were confronted with the necessity to include aspects of syllabuses or school programs which they had previously omitted because of a lack of understanding or appreciation. The corollary was that outcomes promoted greater syllabus fidelity when frameworks were closely aligned. Third, other benefits the teachers associated with outcomes included the development of whole school curriculum resources and greater opportunity for teacher collaboration, particularly among schools. The teachers, however, considered a wide range of factors when determining the overall impact of the reform, and perceived a number of them in terms of the costs of implementation. These included the emergence of ethical dilemmas concerning relationships with students, colleagues and parents, reduced individual autonomy, particularly with regard to the selection of valued curriculum content and intensification of workload with the capacity to erode the relationships with students which teachers strongly associated with the rewards of their profession. Finally, in banding together at the school level to resist aspects of implementation, some teachers showed growing awareness of a collective authority capable of being exercised in response to top-down reform. These findings imply that Student Performance Standards require review and, additional implementation resourcing to support teachers through times of reduced confidence in their own abilities. Outcomes prove an effective means of high-fidelity syllabus implementation, and, provided they are expressed in an accessible way and aligned with syllabus frameworks and terminology, should be considered for inclusion in future syllabuses across a range of learning areas. The study also identifies a range of unintended consequences of outcomes-based curriculum and acknowledges the complexity of relationships among all the aspects of teachers' work. It also notes that the impact of reform on teacher perspectives of professional practice may alter teacher-teacher and school-system relationships in ways that have the potential to influence the effectiveness of future curriculum reform.