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1.
Purpose: To determine the accuracy of critical power (CP) and W? (the curvature constant of the power-duration relationship) derived from self-paced time-trial (TT) prediction trials using mobile power meters to predict 16.1-km road cycling TT performance. This study also aimed to assess the agreement between functional threshold power (FTP) and CP.

Methods: Twelve competitive male cyclists completed an incremental test to exhaustion, a FTP test and 4–5 self-paced TT bouts on a stationary bike within the lab, and a 16.1 km road TT, using mobile power meters.

Results: CP and W? derived from the power-duration relationship closely predicted TT performance. The 16.1-km road TT completion time (26.7 ± 2.2 min) was not significantly different from and was significantly correlated with the predicted time-to-completion (27.5 ± 3.3 min, = 0.89, < 0.01). CP and FTP were not significantly different (275 ± 40 W vs. 278 ± 42 W, > 0.05); however, the limits of agreement between CP and FTP were 30 to -36 W.

Discussion: The findings of this study indicate that CP and W? determined using mobile power meters during maximal, self-paced TT prediction trials can be used to accurately predict 16.1-km cycling performance, supporting the application of the CP and W? for performance prediction. However, the limits of agreement were too large to consider FTP and CP interchangeable.  相似文献   


2.
The aims of the present study were: i) to examine the associations of total accelerometer-based sedentary time (ST) and specific-domain self-reported ST (i.e., screen-based, educational-based, social-based, and other-based ST) with adiposity and physical fitness in youth; and ii) to analyse the mediation effect of physical activity (PA) on associations.

This study was conducted with 415 children (9.1 ± 0.4 years) and 853 adolescents (13.6 ± 1.6 years) in Spain during 2011–2012. Total ST and PA were assessed by accelerometry. Leisure-time spent in twelve sedentary behaviours was self-reported. Adiposity and physical fitness was measured following the ALPHA battery for youth.

Total accelerometer-based ST was positively associated with global adiposity score in children, and negatively associated with global physical fitness score in children and adolescents; but relationships were not independent of PA. PA mediated all associations of accelerometer-based and self-reported ST with adiposity or physical fitness in children. Conversely, screen-, educational-, social-, and other-based ST were negatively related to physical fitness in adolescents, independently of PA.

These findings give an impetus to developing effective strategies for specifically promoting PA in children and for increasing PA while reducing ST in adolescents in order to produce improvements on adiposity and physical fitness.  相似文献   


3.
Objective: To identify major patterns of physical activity (PA), sedentary behavior (SB) and sleeping (all self-reported), and their association with long-term mortality.

Methods: Cohort of 2,851 individuals aged ≥ 60 from Spain. Mortality was ascertain from 2003 up to July 2013. Patterns of PA, SB and sleeping were identified by factor analysis.

Results: During follow-up, 1,145 deaths occurred. The first pattern, named “sedentary and non-active pattern”, was characterized by long sleeping or lying time, and not doing even light PA (household chores or walking). The second pattern was named “active and non-sedentary pattern”, and was characterized long time devoted to vigorous activities, long walking time, and short seating time. Compared to those in the first quartile of the “sedentary and non-active pattern”, those in the highest quartile showed a 71% higher mortality (HR: 1.71; 95%CI: 1.42–2.07; p-trend:<0.001); it corresponds to being 6-year older. By contrast, being in the highest versus the lowest quartile of the “active and non-sedentary pattern” was associated with a 32% lower mortality (HR: 0.68: 0.57–0.82; p-trend:<0.001); it corresponds to being 4-year younger.

Conclusion: The “sedentary and non-active” pattern had a large impact on mortality. The “active and non-sedentary” pattern showed an opposite and slightly lower association.  相似文献   


4.
Purpose: To compare characteristics of club level male soccer players 11 and 13 years of age, and to evaluate playing status in soccer two and 10 years after baseline by birth quarter (BQ).

Methods: Youth players 11 (n = 62, born 1992, observed December 2003) and 13 (n = 50, born 1990, observed April 2004) years were grouped by BQ. Baseline data included stature, weight, maturity status, functional capacities, soccer skills, goal orientation, and coach evaluation of potential. Playing status in soccer in 2006 and 2014 was also available. Baseline characteristics and subsequent playing status were compared by BQ.

Results: Baseline characteristics did not differ by BQ except for age and percentage of predicted adult height. Though not significant, coaches tended to rate players in BQ1as higher in potential. For those competing in soccer as adults, BQ2 (4), BQ3 (5) and BQ4 (2) were represented among players11 years, and BQ1 (3), BQ2 (2), BQ3 (1) and BQ4 (4) among players 13 years.

Conclusion: Although limited to small numbers, differences among players by BQ were inconsistent. The results indicate a need to extend potential explanations of the RAE to include behavioral variables, coaches, training environment, and perhaps the culture of the sport.  相似文献   


5.
Background: Student voice agendas have been slow to permeate higher educational institutions. Curricula in universities, like those in primary and secondary education, are still usually made for students by teachers who, while they may have the best interests of the students in mind, rarely if ever engage students in curriculum decision-making. The need for more equitable, dialogic and democratic engagement by students is particularly relevant in the context of teacher education. It has been argued that pre-service teachers should experience democratic practices during their teacher education experiences in order to have the confidence, knowledge and skills to support democratic opportunities in schools.

Purpose: Through the participatory action research project described in this paper we sought to position pre-service teachers as pedagogical consultants who would design feedback strategies, gather feedback with faculty and co-construct physical education teacher education (PETE) curricula. We saw this process as a democratic possibility that might create opportunities for pre-service teachers to critique and transform their own educational experiences. In this paper we detail the process we used to support dialogue about teaching and learning between students and faculty members and draw on the perspectives of the students, pedagogical consultant, lecturer and teaching and learning advocate involved in this project.

Participants and setting: The project was undertaken with one cohort (77) of pre-service teachers during the final year of a four-year undergraduate PETE programme in an Irish university and focuses on the democratization of one PETE course.

Data collection: Data were generated with and by the pre-service teachers, the pedagogical consultant, the lecturer and the regional teaching and learning advocate. The primary data collection methods were interviews and observation.

Data analysis: The data were reviewed repeatedly looking for patterns, themes, regularities, paradoxes, variations, nuances in meaning and constraints [Rubin and Rubin 1995. Qualitative Interviewing. The art of Hearing Data. London: Sage]. The authors coded all data sets independently using constant comparison [Glaser 1965. “The Constant Comparative Method of Qualitative Analysis.” Social Problems 12 (4): 436–445] and then shared their processes and subsequent codes. Our analysis engages Greene’s [1988. The Dialectic of Freedom. New York: Teachers College Press] dialectical theory, to explore how naming and holding the tensions involved in this research and pedagogical enterprise was not stultifying but generative.

Findings: Three key dialectics were constructed from the data: student–teacher, critical reflection–learning and responsibility–accountability. We speak to each of these themes from the perspectives of the students, the pedagogical consultant and the lecturer who participated in this project.

Discussion and conclusion: Our discussion turns to the challenges and benefits associated with the pursuit and realization of democratic possibilities in PETE.  相似文献   


6.
Primary objective: Teacher evaluation is being revamped by policy-makers. The marginalized status of physical education has protected this subject area from reform for many decades, but in our current era of system-wide, data-based decision-making, physical education is no longer immune. Standardized and local testing, together with structured observation measures, are swiftly being mandated in the USA as required elements of teacher evaluation systems in an effort to improve school programs and student achievement. The purpose of this investigation was to document how this reform was initiated and the experiences of teachers, students and administrators, from three high school physical education programs, during initiation of this reform. Documenting how physical education programs respond to such reforms develops our understanding of top-down reform efforts and helps to identify conditions under which such reforms have the intended effect on physical education teachers and student learning in physical education.

Theoretical framework: Fullan’s three phases of school change has been used to analyze and guide school change efforts in several subject areas including physical education. The phases are initiation, implementation and institutionalization. This study is situated primarily within the first phase of school change, the initiation phase.

Methods and procedures: This study took place over a 21-month period in 3 suburban school districts in a northeast metropolitan area of the USA. Interviews with district physical education administrators, high school physical education teachers and students were conducted. Field notes of physical education classes, informal interviews and related artifacts including pre- and post-physical education assessments were collected. To ensure trustworthiness, several steps were taken including member checks, triangulation and peer review. The data were analyzed to find common themes and patterns using the constant comparative method.

Results: Several themes emerged: (1) changes in curriculum and assessment; (2) effect on administrators; (3) stakeholder apathy and (4) department collaboration.

Conclusion: Changes, although minor, did take place in the wake of this top-down teacher reform; however, additional research needs to be completed to determine whether or not these changes are meaningful or long lasting.  相似文献   


7.
Tools for measuring walking time make use of objective and subjective methods. One subjective approach is to administer physical activity questionnaires (PAQ), mainly because they are inexpensive and easy to give to large groups. The European Prospective Investigation into Cancer and Nutrition (EPIC) study has a brief PAQ (EPIC-PAQ) and includes one question referencing walking time. The objective of this study was to assess the validity of the question about time spent walking included in the EPIC-PAQ.

The sample included 200 older adults (113 women). To assess daily walking time, participants responded to the EPIC-PAQ in an interview and wore a portable gait analysis system and physical activity monitor for 48 consecutive hours in free-living condition.

Results indicated that the mean of bias between the EPIC-PAQ and objetive measurement was ?64.6 min/day. Also, the correlation was low compared to an objective measurement (rho = 0.196) and was positively correlated with the time spent at speeds below 2.5 mph but the correlation was low (slow walking rho = 0.154 and pace walking rho = 0.163).

The EPIC-PAQ shows low correlations with the objective measurement of walking time, that suggests it may be inaccurate and affecting the estimate of the EPIC-PAQ’s PA energy expenditure in this age group.  相似文献   


8.
Background: Teaching for social good and inequity has been presented as needed in sport pedagogy research. However, very little is known how transformative pedagogical practices that teach for social good are implemented and sustained at the elementary level.

Purpose: This digital ethnographic study sought to describe one elementary school physical education (PE) teacher's attempt to employ transformative pedagogy (TP).

Method: Cochran-Smith's [1998. “Teaching for Social Change: Toward a Grounded Theory of Teacher Education.” In The International Handbook of Educational Change, edited by A. Hargreaves, A. Lieberman, M. Fullan, and D. Hopkins, 916–952. Netherlands: Kluwer Academic Publishers, 2004. Walking the Road: Race, Diversity, and Social Justice in Teacher Education. New York: Teachers College Press] pedagogical principles for social justice education (SJE) drove our data collection and analysis. Seven qualitative methods were employed to collect data about Harry's pedagogies, organizational structures, and the content he taught. These were formal and informal interviews, conversations, short films, document collection, social media accounts, and an electronic journal. Data were analyzed using both inductive and deductive methods [Patton 2015. Qualitative Research and Evaluation Methods. 4th ed. Thousand Oaks: Sage].

Findings: Harry's TP and the factors that facilitated and limited his practice were uncovered within five main themes: (a) creating communities of learners through restorative practice principles, (b) building on what students bring to school with them for a democratic curriculum, (c) teaching skills, bridging gaps, and the affective component, (d), working with communities in-between social justice illiteracy, and (e) utilizing diverse forms of assessment.

Conclusion: We confirmed that there is no best way to teach social justice through PE and that TP must be individual to the teacher. In addition, this study highlighted methods and pedagogies by which teachers could engage in TP. Finally, the study's findings implied how teacher educators might go about working with both preservice and inservice PE teachers with the goal that they focus on facilitating social justice through their pedagogical approach.  相似文献   


9.
Background: Within the context of sports coaching and coach education, formalised mentoring relationships are often depicted as a mentor–mentee dyad. Thus, mentoring within sports coaching is typically conceptualised as a one-dimensional relationship, where the mentor is seen as the powerful member of the dyad, with greater age and/or experience [Colley, H. (2003). Mentoring for Social Inclusion. London: Routledge].

Aim: The aim of this study was to explore the concept of a multiple mentor system in an attempt to advance our theoretical and empirical understanding of sports coach mentoring. In doing so, this paper builds upon the suggestion of Jones, Harris, and Miles [(2009). “Mentoring in Sports Coaching: A Review of the Literature.” Physical Education and Sport Pedagogy 14 (3): 267–284] who highlight the importance of generating empirical research to explore current mentoring approaches in sport, which in turn can inform meaningful formal coach education enhancement. The significance of this work therefore lies in opening up both a practical and a theoretical space for dialogue within sports coach education in order to challenge the traditional dyadic conceptualisation of mentoring and move towards an understanding of ‘mentoring in practice’.

Method: Drawing upon Kram’s [(1985). Mentoring at Work: Developmental Relationships in Organisational Life. Glenview, IL: Scott Foresman] foundational mentoring theory to underpin a multiple mentoring support system, 15 elite coach mentors across a range of sports were interviewed in an attempt to explore their mentoring experiences. Subsequently, an inductive thematic analysis endeavoured to further investigate the realities and practicalities of employing a multiple mentoring system in the context of elite coach development.

Results: The participants advocated support for the utilisation of a multiple mentor system to address some of the inherent problems and complexities within elite sports coaching mentoring. Specifically, the results suggested that mentees sourced different mentors for specific knowledge acquisition, skills and attributes. For example, within a multiple mentor approach, mentors recommended that mentees use a variety of mentors, including cross-sports and non-sport mentors.

Conclusion: Tentative recommendations for the future employment of a multiple mentoring framework were considered, with particular reference to cross-sports or non-sport mentoring experiences.  相似文献   


10.
Despite proprietary algorithms to account for differences, output from activity trackers worn on different wrists may not be comparable because individuals vary in their reliance on each hand during free-living activities.

Participants (n = 48) wore Fitbit Flex or Flex2 monitors on each wrist for three days. T tests, equivalence tests, and correlations were used to compare steps, Calories, distance, active minutes, and sleep duration recorded by dominant and nondominant wrist-worn monitors and effect sizes and mean absolute and percent difference were calculated.

The nondominant Flex2 monitor was not equivalent to the dominant wrist-worn monitor and recorded significantly more steps/day (absolute difference = 708), miles/day (0.3), and active minutes/day (7.9) than the dominant Flex2 monitor. For all variables, nondominant and dominant output was correlated (r>0.75).

Nondominant and dominant Flex2 monitors are significantly different, but there were small differences for Flex monitors. Research should investigate effects on behavior and replicate findings using other monitors.  相似文献   


11.
Purpose: This study analysed the effects of a training intervention programme using principles of Non-Linear Pedagogy (NLP) on the decision making (DM) and performance behaviours (P) of youth footballers.

Method: 19 footballers (U12 yrs) participated in 14 training sessions, spread over three phases: Pre-intervention, Intervention, Retention. The intervention was based on Small-Sided and Conditioned Games. We assessed progress during the intervention phase at two different points: intermediate and final. The GPET instrument was used to analyse the DM and P during the completion of 3208 passes in the intervention.

Results: Results shown significant improvements in the DM and P after the intermediate and final points of the acquisition phase. Moreover, significantly higher values were also obtained in both variables in the retention, compared to the pre-intervention phase.

Conclusion: Results indicated that the NLP intervention programme was effective in improving both aspects of team games performance in youth players, with effects consolidated over time.  相似文献   


12.
The ACL-Return to Sport after Injury scale (ACL-RSI) measures athletes’ emotions, confidence in performance, and risk appraisal in relation to return to sport after ACL reconstruction. Aim of this study was to study the validity and reliability of the Dutch version of the ACL-RSI (ACL-RSI (NL)).

Total 150 patients, who were 3–16 months postoperative, completed the ACL-RSI(NL) and 5 other questionnaires regarding psychological readiness to return to sports, knee-specific physical functioning, kinesiophobia, and health-specific locus of control. Construct validity of the ACL-RSI(NL) was determined with factor analysis and by exploring 10 hypotheses regarding correlations between ACL-RSI(NL) and the other questionnaires. For test–retest reliability, 107 patients (5–16 months postoperative) completed the ACL-RSI(NL) again 2 weeks after the first administration. Cronbach’s alpha, Intraclass Correlation Coefficient (ICC), SEM, and SDC, were calculated. Bland–Altman analysis was conducted to assess bias between test and retest.

Nine hypotheses (90%) were confirmed, indicating good construct validity. The ACL-RSI(NL) showed good internal consistency (Cronbach’s alpha 0.94) and test–retest reliability (ICC 0.93). SEM was 5.5 and SDC was 15. A significant bias of 3.2 points between test and retest was found.

Therefore, the ACL-RSI(NL) can be used to investigate psychological factors relevant to returning to sport after ACL reconstruction.  相似文献   


13.
This randomised controlled trial investigated changes in eccentric hamstring strength, 10m sprint speed, and change-of-direction (COD) performance immediately post Nordic hamstring curl (NHC) intervention and following a 3-week detraining period.

Fourteen male team sports athletes were randomised to a do-as-usual control group (CG; = 7) or to a NHC intervention group (NHC; = 7). Isokinetic dynamometry at 180°/s evaluated eccentric hamstring strength immediately post-intervention as the primary outcome measure. Secondary outcomes included 10 m sprint time and COD. Each outcome was measured, pre, immediately post-intervention and following a 3-week detraining period.

Immediately post-intervention significant group differences were observed in the NHC group for eccentric hamstring strength (31.81 Nm?1 vs. 6.44 Nm?1, P = 0.001), COD (?0.12 s vs. 0.20 s; P = 0.003) and sprint (- 0.06 s vs. 0.05 s; P = 0.024) performance. Performance improvements were maintained following a detraining period for COD (?0.11 s vs. 0.20 s; P = 0.014) and sprint (?0.05 s vs. 0.03 s, P = 0.031) but not eccentric hamstring strength (15.67 Nm?1 vs. 6.44 Nm?1, P = 0.145) These findings have important implications for training programmes designed to reduce hamstring injury incidence, whilst enhancing physical qualities critical to sport.  相似文献   


14.
Purpose: This study discusses the process of co-constructing a prototype pedagogical model for working with youth from socially vulnerable backgrounds.

Participants and settings: This six-month activist research project was conducted in a soccer program in a socially vulnerable area of Brazil in 2013. The study included 17 youths, 4 coaches, a pedagogic coordinator and a social worker. An expert in student-centered pedagogy and inquiry-based activism assisted as a debriefer helping in the progressive data analysis and the planning of the work sessions.

Data collection/analysis: Multiple sources of data were collected, including 38 field journal/observation and audio records of: 18 youth work sessions, 16 coaches’ work sessions, 3 combined coaches and youth work sessions, and 37 meetings between the researcher and the expert.

Findings: The process of co-construction of this prototype pedagogical model was divided into three phases. The first phase involved the youth and coaches identifying barriers to sport opportunities in their community. In the second phase, the youth, coaches and researchers imagined alternative possibilities to the barriers identified. In the final phase, we worked collaboratively to create realistic opportunities for the youth to begin to negotiate some of the barriers they identified. In this phase, the coaches and youth designed an action plan to implement (involving a Leadership Program) aimed at addressing the youths’ needs in the sport program. Five critical elements of a prototype pedagogical model were co-created through the first two processes and four learning aspirations emerged in the last phase of the project.

Implications: We suggest an activist approach of co-creating a pedagogical model of sport for working with youth from socially vulnerable backgrounds is beneficial. That is, creating opportunities for youth to learn to name, critique and negotiate barriers to their engagement in sport in order to create empowering possibilities.  相似文献   


15.
16.
Physical inactivity is proven to be a risk factor for non-communicable diseases and all-cost mortality. Public health policy recommends community settings worldwide such as the workplace to promote physical activity. Despite the growing prevalence of workplace team sports, studies have not synthesised their benefits within the workplace.

A systematic review was carried out to identify articles related to workplace team sports, including intervention, observational and qualitative studies. Eighteen studies met the inclusion criteria.

The findings suggest team sport holds benefits not only for individual health but also for group cohesion and performance and organisational benefits such as the increased work performance. However, it is unclear how sport is most associated with these benefits as most of the studies included poorly described samples and unclear sports activities.

Our review highlights the need to explore and empirically understand the benefits of workplace team sport for individual, group and organisational health outcomes. Researches carried out in this field must provide details regarding their respective samples, the sports profile and utilise objective measures (e.g., sickness absence register data, accelerometer data).  相似文献   


17.
This study characterises the relationship between gait variability and speed in runners using data from trunk accelerations in each axis.

Twelve participants of varying fitness ran on the treadmill with three sessions of six randomly ordered self-selected speeds. A VO2max test was conducted on the fourth session. Running gait was tracked with inertial sensors. The occurrence of a mid-range speed was analysed for the anterior–posterior, vertical and lateral directional coefficient of variation (CV) of root mean square (RMS) acceleration data.

One participant with noisy gait signals was omitted. The results show all remaining participants consistently showed significant quadratic U-shaped relationships between vertical RMS CV acceleration and speed. Neither anterior–posterior nor lateral RMS CV acceleration were clearly related to speed. These least variable gait speeds were similar to estimates of optimal speed derived from minimum cost of transport with speed.

In conclusion, there exists a mid-range speed for each runner with the least variable gait in the vertical direction, and this occurred significantly more often than would be expected by chance (P < 0.05). However, there are no prominent patterns for the anterior–posterior and lateral directions. This finding supports anecdotal evidence from runners and coaches concerning gait consistency.  相似文献   


18.
19.
The objective was to systematically review the literature on risk factors and prevention programs for musculoskeletal injuries among tennis players. PubmedMedline, Embase, CINAHL, Cochrane, SportDiscus were searched up to February 2017. Experts in clinical and epidemiological medicine were contacted to obtain additional studies.

For risk factors, prospective cohort studies (n > 20) with a statistical analysis for injured and non-injured players were included and studies with a RCT design for prevention programs. Downs&Black checklist was assessed for risk of bias for risk factors. From a total of 4067 articles, five articles met our inclusion criteria for risk factors. No studies on effectiveness of prevention programs were identified. Quality of studies included varied from fair to excellent.

Best evidence synthesis revealed moderate evidence for previous injury regardless of body location in general and fewer years of tennis experience for the occurrence of upper extremity injuries. Moderate evidence was found for lower back injuries, a previous back injury, playing >6hours/week and low lateral flexion of the neck for risk factors. Limited evidence was found for male gender as a risk factor.

The risk factors identified can assist clinicians in developing prevention-strategies. Further studies should focus on risk factor evaluation in recreational adult tennis players.  相似文献   


20.
Background: Emotional resilience can be vital to longevity in high-poverty school settings. Equally important to staying the course is the ability to remain motivated despite the unique challenges presented by teaching in high-poverty schools. Students within these schools need teachers who are able to manage their emotions and remain positive and optimistic, persist, remain confident, and continually focus on learning and self-improvement no matter their work environment. This study explored four PE teachers’ perceptions of their resilience teaching in high-poverty schools through the lens of resilience theory.

Research design: This study utilized an exploratory multiple case study design (Yin 2003). The main premise of the case study method is to better understand complex educational and social phenomena, while retaining the holistic and meaningful particularities of real-life circumstances (Yin 2003). Teacher interviews and teacher shadowing were used to examine the experiences of PE teachers in high-poverty schools.

Findings: Results indicate that several psychological factors (relating to positive personality, motivation, focus, and perceived social and administrative support) protected the PE teachers in this inquiry from the potential negative effect of stressors by prompting their metacognitions and challenge appraisal. These processes promoted facilitative responses that proved to be key to developing and maintaining their capacities for resilience. The teachers demonstrated a sustained commitment to self-improvement and student success by implementing effective teaching practices.

Conclusion: The teachers in this study possessed strong individual dispositions and were able to demonstrate behaviors that facilitated an elevated level of resilience. School administrators must establish a strong culture of support to enable teacher resilience. Identifying ways to increase the resilience capacity of physical education teachers has the potential to decrease the concerns surrounding teacher attrition and increase job satisfaction for teachers working in high-poverty schools. Implications also indicate a need for physical education teacher education (PETE) programs to identify candidates with the individual dispositions that aid in resilience and provide them with experiences in high-poverty schools. This partnership may assist in minimizing the effects of reality shock oftentimes experienced by new teachers.  相似文献   


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