Objective: To analyse the effect of resistance training (RT) frequency on muscle mass, appendicular lean soft tissue, insulin-like growth factor 1 (IGF-1), testosterone, and their changes with detraining in older women. Methods: Forty-five physically independent older women (≥ 60?years) were randomly assigned to perform RT either two (G2X, n = 21) or three times/week (G3X, n = 24), during 12?weeks (8 exercises, 1 set of 10–15 repetition maximum). Muscle mass and appendicular lean soft tissue, IGF-1, testosterone, and dietary intake were measured at pre-training, post-training, and after detraining (12?weeks). Results: Muscle mass and appendicular lean soft tissue significantly increased post-training (G2X?=?+5.5% and G3X?=?+5.8%, P?.0001) with no differences between groups, and gains were retained after detraining (G2X?=?100% and G3X?=?99%, P?.0001). IGF-1 and dietary intake did not change for the groups during the study. Testosterone did not change post-training but significantly decreased after detraining (G2X?=??21% and G3X?=??50%, P?.0001). Conclusion: We conclude that lower RT frequency is as effective as higher frequency to improve muscle mass and appendicular lean soft tissue, and to maintain testosterone and IGF-1. Additionally, detraining may reduce testosterone regardless of RT frequency. These results are specifically for community-dwelling older women and may not be generalized to other populations. 相似文献
Background: One of the essential elements within Sport Education is the inclusion of student roles and responsibilities. While previous research has examined students’ performance in officiating tasks, the examination of student-coaches’ pedagogical content knowledge (PCK) within peer-assisted tasks of Sport Education has been scarce. Indeed, the only study to date which has examined student-coach effectiveness was conducted by Wallhead and O’Sullivan [2007. “A Didactic Analysis of Content Development During the Peer Teaching Tasks of a Sport Education Season.”Physical Education and Sport Pedagogy 12 (3): 225–243]. In that study, student-coaches struggled to manifest PCK by providing appropriate demonstrations, to diagnose errors, or to modify tasks for higher order content development. The study of PCK may be a useful heuristic to examine instructional effectiveness in physical education.
Purpose: The purpose of this study was to examine the evolution of the PCK of a cohort of student-coaches across three hybrid Sport Education-Step Game Approach seasons, and to examine the impact of protocols put in place to specifically enhance coaches’ PCK.
Participants and setting: Twenty-one students and one teacher from a school class in the north of Portugal participated in the present study.
Method: Data from multiple sources were collected: (a) videotape observations of all lessons, (b) field notes, and (c) pre-lesson interviews with the student-coaches. These were then subjected to deductive examination through a process of thematic analysis.
Findings and conclusions: Following a baseline season that identified four key limitations within the student-coaches’ instruction (task presentation, error diagnosis, feedback, and task modification), these students participated in specific coach preparation that involved modelling teacher’s instruction, pre-lesson meetings, and coaches’ corners. While showing marked improvement in their content knowledge across the second season, a second protocol was instigated during the third that involved the student-coaches to participate in stimulated reflections of their instruction and the incorporation of planning sheets to enhance their instruction. It was found that both interventions were efficacious in developing student-coaches’ PCK, which allowed a more complete transfer of the instructional responsibility from the teacher to the students. These results give insight into the importance of including coach education protocols within the design of seasons of Sport Education with respect to student-coaches’ instructional preparation. 相似文献
The present study aimed to examine how high- and low-speed swimmers organise biomechanical, energetic and coordinative factors throughout extreme intensity swim. Sixteen swimmers (eight high- and eight low-speed) performed, in free condition, 100-m front crawl at maximal intensity and 25, 50 and 75-m bouts (at same pace as the previous 100-m), and 100-m maximal front crawl on the measuring active drag system (MAD-system). A 3D dual-media optoelectronic system was used to assess speed, stroke frequency, stroke length, propelling efficiency and index of coordination (IdC), with power assessed by MAD-system and energy cost by quantifying oxygen consumption plus blood lactate. Both groups presented a similar profile in speed, power output, stroke frequency, stroke length, propelling efficiency and energy cost along the effort, while a distinct coordination profile was observed (F(3, 42) = 3.59, P = 0.04). Speed, power, stroke frequency and propelling efficiency (not significant, only a tendency) were higher in high-speed swimmers, while stroke length and energy cost were similar between groups. Performing at extreme intensity led better level swimmers to achieve superior speed due to higher power and propelling efficiency, with consequent ability to swim at higher stroke frequencies. This imposes specific constraints, resulting in a distinct IdC magnitude and profile between groups. 相似文献
Many of the current approaches used in teaching and learning in engineering education are not the most appropriate to prepare students for the challenges they will face in their professional careers. The active involvement of students in their learning process facilitates the development of the technical and professional competencies they need as professionals. This article describes the organisation and impact of a mini-conference and project work – the creation of a software product and its introduction in the market – aimed at the development of professional competencies in general and writing skills in particular. The course was evaluated by assessing the students’ perception of the development of a number of professional competencies through a questionnaire completed by 125 students from two consecutive year groups. The results indicate that the project work and the mini-conference had a positive impact on students’ perceptions of the development of professional competencies. 相似文献
Background: Scientific excellence is one of the most fundamental underpinnings of medical education and its relevance is unquestionable. To be involved in research activities enhances students' critical thinking and problem-solving capacities, which are mandatory competences for new achievements in patient care and consequently to the improvement of clinical practice. Purposes: This work aimed to study the relevance given by Portuguese medical students to a core of scientific skills, and their judgment about their own ability to execute those skills. Methods: A cross-sectional study was conducted on students attending the first, fourth and sixth years of medical course in the same period. An assessment istrument, exploring the importance given by Portuguese medical students to scientific skills in high school, to clinical practice and to their own ability to execute them, was designed, adapted and applied specifically to this study. Results: Students' perceptions were associated with gender, academic year, previous participation in research activities, positive and negative attitudes toward science, research integration into the curriculum and motivation to undertake research. The viewpoint of medical students about the relevance of scientific skills overall, and the ability to execute them, was independently associated with motivation to be enrolled in research. Conclusions: These findings have meaningful implications in medical education regarding the inclusion of a structural research program in the medical curriculum. Students should be aware that clinical practice would greatly benefit from the enrollment in research activities. By developing a solid scientific literacy future physicians will be able to apply new knowledge in patient care. 相似文献
ABSTRACTThis collaborative self-study explores how educators’ pedagogical identities developed in the process of learning to use a Student-Centered Inquiry as Curriculum (SCIC) approach in activity settings within a community of practice (CoP). Participants included a university professor, college instructor, postdoctoral student and doctoral student. Data included 16 weekly field notes and debriefings following observations, teacher artifacts, 16 weekly collaborative group meetings, and 3 90-minute interviews per teacher. Culture, values, beliefs and professional background were critical for the development of the teachers’ pedagogical identities in the process of learning to use a SCIC approach within a community of practice. These experiences created for some, places to further develop their ideas about teaching, whereas for others they caused great discomfort and a sense of personal loss. The CoP facilitated the development of the teachers’ pedagogical identities, changing positionalities, and negotiating culture, values, beliefs and professional backgrounds. 相似文献
The aims of this study were: (1) to observe participation in moderate-to-vigorous physical activity (MVPA) during school recess periods; (2) to determine the relative importance of physical activity during recesses to overall daily physical activity; and (3) to examine differences in physical activity between the sexes during unstructured recess periods. The participants were 22 school children (10 boys, 12 girls) aged 8?–?10 years (mean = 8.9, s = 0.7) in the third and fourth grades. Daily totals for the physical activity variables were calculated by summing the values for each hour of 14?h of physical activity measurements (08:00 to 22:00?h). Recess times (minutes) were as follows: morning 10:30 to 11:00?h and afternoon 15:30 to 16:00?h. We did not differences between boys and girls in daily total accelerometer counts or the overall time spent in MVPA. However, girls were significantly (P <?0.05) more involved (38%) in MVPA during recess time than boys (31%). Participation in MVPA during recess contributes significantly more (P <?0.05) for girls (19%) than boys (15%) to the total amount of physical activity suggested by international health-related physical activity guidelines, while the percentage of time engaged in MVPA during recess time at school accounts for a small amount of the daily MVPA (6% for boys and 8% for girls). The results of this study suggest that school recess time is an important setting to promote MVPA and contributes to daily physical activity in young children, especially in girls. 相似文献
Abstract We assessed the agreement between maximal oxygen consumption ([Vdot]O2max) measured directly when performing the 20-m shuttle run test and estimated [Vdot]O2max from five different equations (i.e. Barnett, equations a and b; Léger; Matsuzaka; and Ruiz) in youths. The 20-m shuttle run test was performed by 26 girls (mean age 14.6 years, s = 1.5; body mass 57.2 kg, s = 8.9; height 1.60 m, s = 0.06) and 22 boys (age 15.0 years, s = 1.6; body mass 63.5 kg, s = 11.5; height 1.70 m, s = 0.01). The participants wore a portable gas analyser (K4b2, Cosmed) to measure [Vdot]O2 during the test. All the equations significantly underestimated directly measured [Vdot]O2max, except Barnett's (b) equation. The mean difference ranged from 1.3 ml · kg?1 · min?1 (Barnett (b)) to 5.5 ml · kg?1 · min?1 (Léger). The standard error of the estimate ranged from 5.3 ml · kg?1 · min?1 (Ruiz) to 6.5 ml · kg?1 · min?1 (Léger), and the percentage error ranged from 21.2% (Ruiz) to 38.3% (Léger). The accuracy of the equations available to estimate [Vdot]O2max from the 20-m shuttle run test is questionable at the individual level. Furthermore, special attention should be paid when comparisons are made between studies (e.g. population-based studies) using different equations. The results of the present study suggest that Barnett's (b) equation provides the closest agreement with directly measured [Vdot]O2max (cardiorespiratory fitness) in youth. 相似文献
In this paper we investigate the link between the language in which pupils take the Programme for International Student Assessment (PISA) test and the scores they achieve in this assessment, focusing upon the case of Wales. Using five rounds of PISA data and an instrumental variable approach, we show how pupils who took the test in Welsh score around 0.3 standard deviations (30 PISA test points) lower in reading, mathematics and science than their peers who took the test in English. This finding is robust to different model specifications and statistical approaches. We argue that this may indicate that the academic performance of teenagers in Wales may be underestimated in PISA – particularly amongst those who take this test in Welsh. 相似文献