Power output of field-based downhill mountain biking

Abstract

The purpose of this study was to assess the power output of field-based downhill mountain biking. Seventeen trained male downhill cyclists (age 27.1 ± 5.1 years) competing nationally performed two timed runs of a measured downhill course. An SRM powermeter was used to simultaneously record power, cadence, and speed. Values were sampled at 1-s intervals. Heart rates were recorded at 5-s intervals using a Polar S710 heart rate monitor. Peak and mean power output were 834 ± 129 W and 75 ± 26 W respectively. Mean power accounted for only 9% of peak values. Paradoxically, mean heart rate was 168 ± 9 beats · min^?1 (89% of age-predicted maximum heart rate). Mean cadence (27 ± 5 rev · min^?1) was significantly related to speed (r = 0.51; P < 0.01). Analysis revealed an average of 38 pedal actions per run, with average pedalling periods of 5 s. Power and cadence were not significantly related to run time or any other variable. Our results support the intermittent nature of downhill mountain biking. The poor relationships between power and run time and between cadence and run time suggest they are not essential pre-requisites to downhill mountain biking performance and indicate the importance of riding dynamics to overall performance.     

University students’ conceptions of the good teacher: A Hong Kong perspective

One way that universities assess teaching effectiveness is by eliciting student feedback. However, what standards do students themselves use to judge whether a lecturer is a ‘good’ teacher? As part of a study carried out at a Hong Kong university, students were interviewed about their first-year learning experience and asked what they felt constituted ‘good’ and “bad’ teaching. Unlike when asked to complete teacher effectiveness surveys, no criteria or characteristics were given. Responses focused primarily on teaching skills that supported student learning and encouraged critical thinking, particularly the teacher’s ability to give clear explanations supported by relevant, practical examples.     

Management teams and the promotion of staff well‐being

For several years small primary schools have been threatened with closure and their viability is frequently a subject of much discussion. One of the major issues in this debate, particularly in light of the 1988 Education Reform Act, is whether they can provide an effective education for their pupils due to their size and their mixed age range classes. This article discusses the major arguments related to this issue and draws several important conclusions to guide practice and decision making not only in small schools, but also in all other primary schools where differentiation in teaching and learning methods is now of crucial significance. Supporting evidence is taken mainly from a Teacher Fellowship project funded by West Glamorgan County Council.     

Practice Theory: Viewing leadership as leading

Abstract

Inspired by Theodore Schatzki’s ‘societist’ approach—in which he advocates a notion of ‘site ontologies’—in this article, we outline our theory of practice architectures (a theory about what practices are composed of) and ecologies of practices (how practices relate to one another). Drawing on case studies of four Australian primary schools, we examine how practices of leading relate to other educational practices: professional learning, teaching, student learning, and researching and reflecting. We find ‘leading’ not only in the work of principals and other formal leadership positions, but also in the activities of teachers and students. We show that changing leading practices requires changing more than the professional practice knowledge of individuals; it also requires changing the practice architectures (cultural-discursive, material-economic and social-political arrangements) in sites where leading and its interconnected practices are conducted. In order to study practices of leading, we adopt a philosophical-empirical enquiry approach, i.e. we conduct our research as a conversation between practice philosophy and theory and the empirical cases of leading we study. We study practices in the mode of research within practice traditions, sometimes described as ‘practical philosophy’, as a contribution to the self-reflective transformation of the practices we are studying.     

The link: Addressing the problems of higher education through the core curriculum

Three major national reports on the status of American Higher Education have surfaced seven distinct problems common to many colleges and universities. Saint Mary-of-the-Woods College anticipated these problems in 1981 and has undertaken to address them through the development of a sixty-hour, developmentally arranged general studies sequence entitledThe Link. The success ofThe Link illustrates that the core curriculum can be an effective medium for dealing with these problems when approached by faculty in a spirit of innovation and cooperation.     

Standardization and UNDERSTANDardization in Educational Assessment

Educational tests are standardized so that all examinees are tested on the same material, under the same testing conditions, and with the same scoring protocols. This uniformity is designed to provide a level “playing field” for all examinees so that the test is “the same” for everyone. Thus, standardization is designed to promote fairness in testing. In practice, the material tested, the conditions under which a test is administered, and the scoring processes, are often too rigid to provide the intended level playing field. For example, standardized testing conditions may interact with personal characteristics of examinees that affect test performance, but are not construct-relevant. Thus, more flexibility in standardization is needed to account for the diversity of experiences, talents, and handicaps of the incredibly heterogeneous populations of examinees we currently assess. Traditional standardization procedures grew out of experimental psychology and psychophysics laboratories where keeping all conditions constant was crucial. Today, accounting for and measuring what is not constant across examinees is crucial to valid construct interpretations. To meet this need I introduce the concept of understandardization, which refers to ensuring sufficient flexibility in standardized testing conditions to yield the most accurate measurement of proficiency for each examinee.     

The effect of crank inertial load on the physiological and biomechanical responses of trained cyclists

The existing literature suggests that crank inertial load has little effect on the responses of untrained cyclists. However, it would be useful to be aware of any possible effect in the trained population, particularly considering the many laboratory-based studies that are conducted using relatively low-inertia ergometers. Ten competitive cyclists (mean VO(2max) = 62.7 ml x kg(-1) x min(-1), s = 6.1) attended the human performance laboratories at the University of Wolverhampton. Each cyclist completed two 7-min trials, at two separate inertial loads, in a counterbalanced order. The inertial loads used were 94.2 kg x m(2) (high-inertia trial) and 2.4 kg x m(2) (low-inertia trial). Several physiological and biomechanical measures were undertaken. There were no differences between inertial loads for mean peak torque, mean minimum torque, oxygen uptake, blood lactate concentration or perceived exertion. Several measures showed intra-individual variability with blood lactate concentration and mean minimum torque, demonstrating coefficients of variation > 10%. However, the results presented here are mostly consistent with previous work in suggesting that crank inertial load has little direct effect on either physiology or propulsion biomechanics during steady-state cycling, at least when cadence is controlled.     

Ventilatory Threshold,Running Economy and Distance Running Performance of Trained Athletes

Abstract

The purpose of this study was to assess the relationships among ventilatory threshold T(vent), running economy and distance running performance in a group (N=9) of trained experienced male runners with comparable maximum oxygen uptake ([Vdot]O₂ max). Maximal oxygen uptake and submaximal steady state oxygen uptake were measured using open circuit spirometry during treadmill exercise. Ventilatory threshold was determined during graded treadmill exercise using non-invasive techniques, while distance running performance was assessed by the best finish time in two 10-kilometer (km) road races. The subjects averaged 33.8 minutes on the 10km runs, 68.6 ml · kg ^-1 · min ^-1 for [Vdot]O₂ max, and 48.1 ml · kg ^-1 · min ^-1 for steady state [Vdot]O₂ running at 243 meters · min ^-1. The T(vent) (first deviation from linearity of [Vdot]_E, [Vdot]CO ₂ ) occurred at an oxygen consumption of 41.9 ml · kg ^-1 · min ^-1. The relationship between running economy and performance was r = .51 (p>0.15) and the relationship between T(vent) and performance was r = .94 (p < 0.001). Applying stepwise multiple linear regression, the multiple R did not increase significantly with the addition of variables to the T(vent); however, the combination of [Vdot]O₂ max, running economy and T(vent) was determined to account for the greatest amount of total variance (89%). These data suggest that among trained and experienced runners with similar [Vdot]O₂ max, T(vent) can account for a large portion of the variance in performance during a 10km race.     

The relationship of school‐wide Positive Behavior Support to academic achievement in an urban middle school

An emerging literature on school‐wide Positive Behavior Support (PBS) in urban settings suggests the utility of PBS in addressing student social development while decreasing the need for disciplinary actions (i.e., office disciplinary referrals [ODRs]). This research represents a significant addition to, and expansion of, this literature by examining the relationship of school‐wide PBS‐induced reductions in out‐of‐class referrals to student academic achievement. School‐wide PBS was implemented in an urban, inner‐city middle school in the Midwest over a 3‐year period. Data on ODRs, suspensions, standardized test scores, and treatment fidelity were gathered and analyzed. Results demonstrated significant reductions in ODRs and suspensions and increases in standardized math and reading scores. Additionally, regression analyses suggested a significant relationship between student problem behavior and academic performance. Treatment adherence to PBS procedures was significantly correlated with reductions in problem behavior. These findings are discussed in terms of helping urban schools address challenging behavior. © 2006 Wiley Periodicals, Inc. Psychol Schs 43: 701–712, 2006.     

Cross-sectional comparison of body composition and resting metabolic rate in Premier League academy soccer players: Implications for growth and maturation

ABSTRACT

For the first time we aimed to: (1) assess fat-free mass (FFM) and RMR in youth soccer players, (2) compare measured RMR to estimated RMR using previously published prediction equations, and (3) develop a novel population-specific prediction equation. In a cross-sectional design, 99 males from a Premier League academy underwent assessments of body composition (DXA) and RMR (indirect-calorimetry). Measured RMR was compared to estimated values from five prediction equations. A novel RMR prediction equation was developed using stepwise multiple regression. FFM increased (P<0.05) between U12 (31.6±4.2 kg) and U16 (56.3±5.3 kg) after which no further increases occurred (P>0.05). RMR in the U12s (1655±195 kcal.day^?1), U13s (1720±205 kcal.day^?1) and U14s (1846±218kcal.day^?1) was significantly lower than the U15s (1957±128 kcal.day^?1), U16s (2042±155 kcal.day^?1), U18s (1875±180 kcal.day^?1) and U23s (1941±197 kcal.day^?1) squads (P>0.05). FFM was the single best predictor of RMR (r²=0.43; P<0.01) and was subsequently included in the novel prediction equation: RMR (kcal.day^?1) = 1315 + (11.1 x FFM in kg). Both FFM and RMR increase from 12-16 years old, thus highlighting the requirement to adjust daily energy intake to support growth and maturation. The novel prediction RMR equation developed may help to inform daily energy requirements.