The organised chaos of English adolescent rugby union: Influence of weekly match frequency on the variability of match and training loads

The aims of this study were to determine the variability of weekly match and training loads in adolescent rugby union players across a competitive season, and to investigate the effect of match frequency on load distribution across different activities. Internal match and training load data (i.e. session-rating of perceived exertion (sRPE)) were collected daily from 20 players from a regional academy across a 14-week season. Data were analysed using a mixed-effects linear model, and variability was reported as a coefficient of variation (CV). Differences between 0-, 1-, 2-, and 3-match weeks were assessed using Cohen’s d effect sizes and magnitude-based inferences. Mean weekly total match and training sRPE load was 1425?±?545 arbitrary units (AU), with a between-player CV of 10?±?6% and within-player CV of 37?±?3%. Mean week-to-week change in total sRPE load was 497?±?423?AU (35%), and 40% of weekly observations were outside the suggested acute:chronic workload ratio ‘safe zone’. Total weekly sRPE loads increased substantially with match frequency (1210?±?571, 1511?±?489, and 1692?±?517?AU, for 0-, 1-, and 2-match weeks, respectively), except for 3-match weeks (1520?±?442?AU). Weekly match and training loads were highly variable for adolescent rugby players during the competitive season, and match frequency has a substantial effect on the distribution of loads. Therefore, match and training loads should be coordinated, monitored, and managed on an individual basis to protect players from negative training consequences, and to promote long-term athlete development.     

The lived ethics of abstinence: Christian young men’s experiences of romantic relationships

Relationships and sex education (RSE), as set out in the recent Bill making RSE compulsory for all English schools, should be appropriate to the religious background of pupils. This paper suggests that this appropriateness is best found by gaining the best understanding about religious young people’s lived experiences of relationships and sexuality. Our in-depth qualitative research with three Christian young men aged 17–18 from a large charismatic evangelical church in the Midlands region of England investigated experiences of romantic relationships, focusing on the ‘ethical moments’ in which Christian ethical principles of sexual abstinence are negotiated. By attending closely to both the theological and the non-religious discursive resources that these negotiations draw upon, we demonstrate the different ways in which abstinence becomes meaningful in study participants' lifeworlds. We conclude that a sex education based on ethics in practice might engage best with religious young people.     

The physical characteristics of match-play in English schoolboy and academy rugby union

The aim was to compare the physical characteristics of under-18 academy and schoolboy rugby union competition by position (forwards and backs). Using a microsensor unit, match characteristics were recorded in 66 players. Locomotor characteristics were assessed by maximum sprint speed (MSS) and total, walking, jogging, striding and sprinting distances. The slow component (<2 m · s^?1) of PlayerLoad^TM (PL_slow), which is the accumulated accelerations from the three axes of movement, was analysed as a measure of low-speed activity (e.g., rucking). A linear mixed-model was assessed with magnitude-based inferences. Academy forwards and backs almost certainly and very likely covered greater total distance than school forwards and backs. Academy players from both positions were also very likely to cover greater jogging distances. Academy backs were very likely to accumulate greater PL_slow and the academy forwards a likely greater sprinting distance than school players in their respective positions. The MSS, total, walking and sprinting distances were greater in backs (likely-almost certainly), while forwards accumulated greater PL_slow (almost certainly) and jogging distance (very likely). The results suggest that academy-standard rugby better prepares players to progress to senior competition compared to schoolboy rugby.     

Dribble Deficit: A novel method to measure dribbling speed independent of sprinting speed in basketball players

Basketball tests assessing dribbling speed predicated on total performance times are influenced by sprinting speed. This study examines an approach termed Dribble Deficit to counter this limitation by examining the relationships between sprinting and dribbling speed during linear and change-of-direction (COD) tasks measured using total performance time and Dribble Deficit. Ten semi-professional basketball players completed linear sprints and COD sprints with and without dribbling. Dribble Deficit was calculated as the difference between the best time for each dribbling trial and corresponding non-dribbling trial for linear and COD sprints. Large to very large significant relationships (P < 0.05) were evident between linear sprint and dribble times (R = 0.64–0.77, R² = 0.41–0.59), and between COD sprint and dribble times (R = 0.88, R² = 0.77). Conversely, trivial-small relationships were evident between linear sprint time and linear Dribble Deficit (R = 0.01–0.15, R² = 0.00–0.02). A non-significant, moderate, negative relationship was observed between COD sprint time and COD Dribble Deficit (R = ?0.45, R² = 0.20). These findings indicate Dribble Deficit provides a more isolated measure of dribbling speed than tests using total performance times. Basketball practitioners may use Dribble Deficit to measure dribbling speed independent of sprint speed in test batteries.     

Acute responses to sprint-interval and continuous exercise in adults with and without exercise-induced bronchoconstriction

The purpose was to compare the airway response to sprint interval exercise (SIE) and continuous exercise (CE) in active adults with exercise-induced bronchoconstriction (EIBC), and to compare ventilatory and oxygen delivery responses between adults with and without EIBC. Adults with EIBC (n = 8, 22.3 ± 3.0 years) and adults without EIBC (n = 8, 22.3 ± 3.0 years) completed a SIE (4 × 30 s sprints separated by 4.5 min of active recovery) and CE (20 min at 65% peak power output) session. Lung function was assessed at baseline, during exercise, and up to 20 min post-exercise. Ventilatory parameters and tissue saturation index (TSI) were recorded continuously throughout the sessions. The decline in forced expiratory volume in 1 s was similar following SIE (?8.6 ± 12.6%) and CE (?9.0 ± 9.3%) in adults with EIBC. There were no significant differences in any of the ventilatory parameters or in TSI during SIE or CE between those with and without EIBC. These findings suggest that SIE and CE affect airway responsiveness to a similar extent. Future research using a lower intensity CE protocol in an inactive sample of adults with EIBC is needed.     

The influence of hip mobility and quadriceps fatigue on sagittal spinal posture and muscle activation in rugby scrum performance

Rugby Union scrumming puts the spine under a high degree of loading. The aim of the current study was to determine how sagittal hip range of motion and quadriceps fatigue influence force output, spinal posture, and activation of the trunk and quadriceps muscles in rugby scrumming. Measures of sagittal hip flexion/extension range of motion were collected from 16 male varsity and club first XV level participants. Sagittal spine motion (electromagnetic motion capture), trunk and quadriceps activation (electromyography), and applied horizontal compressive force (force plate) were measured during individual machine scrumming. Participants performed a 5-trial scrum block involving 5?s of contact with 1–2?min recovery between each trial. They then performed a fatiguing protocol (wall sit to failure) and immediately returned to the scrum machine to perform another five trials. Though there was no significant influence of fatigue on the horizontal compressive force applied during contact (P?=?.83), there was a 52% increase in cervical flexion (P?P?P?相似文献   

Idle chatter or compelling conversation? The potential of the social media-based #NGSSchat network for supporting science education reform efforts

The Next Generation Science Standards (NGSS) chat (#NGSSchat) is a social media-based professional network used to discuss topics related to the NGSS in the United States. While successful reforms involve and coordinate the work of multiple stakeholders, recent research points out a striking lack of coordination between the individuals working in different educational roles—to the detriment of intended changes in the system. In this study, we analyzed more than 7,000 posts from individuals participating in #NGSSchat on Twitter (n = 247) during 2 years of 1-hr synchronous discussions. We studied the depth and types of conversations that took place, the extent to which the involvement of teachers, administrators, researchers, and organizations was balanced, and what explains participation in the network over time. Using a mixed-methods approach involving social network analysis, we found that conversations were primarily transactional, or social, and substantive, or providing opportunities for sense-making about the standards or for participants to transform their practice and that individuals from diverse roles participated, with teachers comprising the plurality of those involved. Additionally, researchers, administrators, and teachers were the most active in the network, with no differences in both initiating, or sending, and being the recipients of, or receiving, replies as a part of conversations. Finally, we found that being a teacher or administrator, as well as receiving replies from individuals who were important in the network, were positively related to sustained involvement in the network in the following year. We discuss how #NGSSchat—as a social media-based professional network—demonstrates similar features in other effective networks, and how social media-based networks invite new visions for how to implement ambitious, large-scale changes in science education.     

Thinking ecologically with Judith Butler

This essay traces several productive points of overlap and departure between the recent philosophical work of Judith Butler and ecological thinking. While ecological philosophers and theorists have often dismissed Butler's treatment of politics and ethics as narrowly anthropocentric, this essay charges that there are considerable conceptual resources within Butler's oeuvre that are not only in accord with much recent ecological theorising but which also stand to enrich our approaches to ecological thinking and politics. Focusing specifically on three conceptual clusters – exposure and precarity; infrastructure and coexistence; and assemblies and assemblages – this essay demonstrates how Butler's work can be leveraged to augment the ways we approach both ecosystems and our more-than-human cohabitants as elements of and actors within the dynamic play of forces that make coexistence more or less possible.