Kinetic and kinematic patterns during high intensity clean movement: searching for optimal load

The aim of the present study was to investigate loading effects on kinematic and kinetic variables among elite-weightlifters in order to identify an optimal training load to maximize power production for clean-movement. Nine elite-weightlifter (age: 24 ± 4years, body-mass: 77 ± 6.5kg, height: 176 ± 6.1cm and 1RM clean: 170 ± 5kg) performed 2 separate repetitions of the clean using 85, 90, 95% and 100%, in a randomized order, while standing on a force platform and being recorded using 3D-capture-system. Differences in kinematics (barbell displacement, velocity and acceleration) and kinetics (power, vertical ground reaction force (vGRF), rate of force development (RFD), and work) across the loads were statistically assessed. Results revealed significant load effects for the majority of the studied parameters (p < 0.01) and showed that typical bar-displacement, greatest bar-velocity and peak-power were achieved at 85 and 90% 1RM (p < 0.001). Additionally greater average power was shown for 90 and 95% (p < 0.01) and greater work and vGRF were shown for 90, 95 and 100% than 85% 1RM (p < 0.05). Load had no significant effect on peak-vGRF and peak-RFD (p > 0.05). The results of this study, suggest 90% 1RM to be the most advantageous load to train explosive-force and to enhance power-outputs while maintaining technical efficiency in elite-weightlifters.     

Cellular activation of selected signaling proteins through resistance training—a training methodological perspective

The Akt-mTOR-p70^S6k-4E-BP1 signaling pathway is a well-considered regulator of protein synthesis in the context of strength training. This process is essential for exercise-induced skeletal muscle growth. The objective of this review article was to analyze the design of acute resistance training protocols and evaluate the possible impact of different loading conditions on the activation of growth-related signaling cascades in human skeletal muscle. In all, 12 human studies were included in this review. The training intensity in the studies varied between 30% 1RM (one repetition maximum) and maximal load. The signaling proteins were measured in a time range between immediately and 24?h after training.The phosphorylation of all signaling proteins increased to different levels after resistance training, tending to baseline more than 6?h post training. In particular, the hypertrophic associated p70^S6k showed the highest phosphorylation acutely after the load and decreased consistently after 6?h. Training intensity and volume seemed to have an influence on the extent of protein phosphorylation, which, however, was not systematic or consistent. An obvious training methodological consequence (load and volume) for hypertrophic resistance training regime could not be devised. Further research is required to systematically vary training parameters to determine the influence of a certain stress zone on the signaling activation. Future research should aim to identify the ideal level of training intensity necessary to achieve the greatest possible extent of intramuscular anabolic signaling through intense activation of the signaling cascade to induce growth in human skeletal muscle.     

Klassifikation von Leistungsprofilen im Handballsprungwurf

The jump throw is one of the most applied techniques in handball. Therefore, analyzing its underlying performance factors is important since they may provide a basis to adjust training interventions. Currently, the coach decides what needs to be improved in order to enhance the overall performance of an athlete. The aim of this study is to break down the performance factors in jump throws and to assign athletes to subgroups. This classification should allow athletes to benefit from the resulting group-specific training contents and may support a coach in deciding about the next steps in his training program. A total of 113 male handball players (age 15 ± 0.38 years, height 184.07 ± 7.1?cm, weight 74.83 ± 9.31?kg) participated in this study. From each athlete the standing reach height (SRH), the jumping reach height achieved with a countermovement jump (JRH), the maximal ball height achieved with a handball-specific single-legged jump and straight arm (BHJ), and the ball release height achieved in a jump throw (BHT) were measured. Performance factors were derived as differences between these measurements (JRH ? SRH = UJA for unspecific jump ability, BHJ ? JRH = SJT for specific jump technique, BHT ? BHJ = STT for specific throwing technique). A hierarchical cluster analysis was used to find groups of athletes based on the derived and scaled difference measures (UJA, SJT, STT). The dendrogram shows a clear distinction of four groups of athletes. Average values within each cluster reveal (A) one group with high UJA values, (B) one with low UJA values, (C) one with high SJT but low STT, and (D) one with low SJT but high STT. These results may be interpreted with respect to consequences for training because group (B) seems to benefit most from a general strength training while the properties of group (A), (C), and (D) recommend a focus on technical aspects of performance.     

What is influencing the dropout behaviour of youth players from organised football?

This article provides a systematised review of relevant factors influencing youth dropout from organised football. The findings of identified 30 studies concerning dropout behaviour in football indicate the multidimensional influences of intrapersonal, interpersonal and structural factors. Most studies investigate the influence of intrapersonal factors. Accordingly, negatively perceived football competence, lack of motivation, goals and incentives and a lower relative age lead to a higher dropout rate. At the interpersonal level, lack of support from significant others (parents, peers, coach) and a disadvantageous team situations promote withdrawal from organised youth football. A lack of organisational and structural conditions promote dropout too. Based on this review, the following identified research gaps should be addressed in future studies: (1) analysis of individuals’ dropout decision as a selection of available alternatives, (2) referencing to corresponding contextual features of dropout behaviour, (3) the longitudinal perspective at dropout behaviour and (4) the perspective of intervention. Furthermore, some practical implications can be derived for the management of youth members in football clubs: (1) strengthen and develop successive coaching competencies, (2) reflection of own club philosophy against the background of divergent expectations of adolescents, (3) measures to promote identification with the football club and (4) anchoring of orientation regarding to young players as a central objective in the club.     

Predicting biathlon shooting performance using machine learning

Shooting in biathlon competitions substantially influences final rankings, but the predictability of hits and misses is unknown. The aims of the current study were A) to explore factors influencing biathlon shooting performance and B) to predict future hits and misses. We explored data from 118,300 shots from 4 seasons and trained various machine learning models before predicting 34,340 future shots (in the subsequent season). A) Lower hit rates were discovered in the sprint and pursuit disciplines compared to individual and mass start (P < 0.01, h = 0.14), in standing compared to prone shooting (P < 0.01, h = 0.15) and in the 1^st prone and 5^th standing shot (P < 0.01, h = 0.08 and P < 0.05, h = 0.05). B) A tree-based boosting model predicted future shots with an area under the ROC curve of 0.62, 95% CI [0.60, 0.63], slightly outperforming a simple logistic regression model and an artificial neural network (P < 0.01). The dominant predictor was an athlete’s preceding mode-specific hit rate, but a high degree of randomness persisted, which complex models could not substantially reduce. Athletes should focus on overall mode-specific hit rates which epitomise shooting skill, while other influences seem minor.     

On the impact of quantum computing technology on future developments in high-performance scientific computing

Quantum computing technologies have become a hot topic in academia and industry receiving much attention and financial support from all sides. Building a quantum computer that can be used practically is in itself an outstanding challenge that has become the ‘new race to the moon’. Next to researchers and vendors of future computing technologies, national authorities are showing strong interest in maturing this technology due to its known potential to break many of today’s encryption techniques, which would have significant and potentially disruptive impact on our society. It is, however, quite likely that quantum computing has beneficial impact on many computational disciplines. In this article we describe our vision of future developments in scientific computing that would be enabled by the advent of software-programmable quantum computers. We thereby assume that quantum computers will form part of a hybrid accelerated computing platform like GPUs and co-processor cards do today. In particular, we address the potential of quantum algorithms to bring major breakthroughs in applied mathematics and its applications. Finally, we give several examples that demonstrate the possible impact of quantum-accelerated scientific computing on society.     

Apprentice or Student? The Structures of Construction Industry Vocational Education and Training in Denmark and Sweden and their Possible Consequences for Safety Learning

There is a notable difference in occupational injury rates in the two Scandinavian countries, Sweden and Denmark, with the latter having a 40% higher rate of fatal occupational injuries in the construction industry. This study explored differences in the vocational education and training (VET) systems between Sweden and Denmark that may be important for students’ safety learning and practice during VET. In both countries, students participate in full-time education, and the curriculum includes school-based as well as company- based training. However, during company- based training Swedish students retain their student status, whereas Danish students are employed as apprentices. From a perspective of viewing safety as a social practice developed through interactions of different social and institutional bodies, the analysis points to this difference in employment status as important for their safety practices and also for the teachers’ position to influence safety learning and practices during company-based training. An analysis of interview and survey data focusing on how VET students enact safety ‘knowings’ across learning sites, suggest how different forms of connectivity models in VET promote various forms of safety learning among students.     

Violent Extremism,National Security and Prevention. Institutional Discourses and their Implications for Schooling

Currently, threats to societal security from extremist groups are high on the political agenda in many countries. Politicians, policymakers at various levels and communities are searching for methods to counteract recruitment to violent organizations. These efforts are often referred to as Prevention of Violent Extremism (PVE-programmes). One of the earliest PVE programmes in Europe was the British PREVENT programme, and it has to some extent served as a model for other countries, including Sweden. In this article, we scrutinize a particular method, inspired by the PREVENT, and developed by the Swedish National Coordinator against violent extremism, called The Conversation Compass (CC) intended for so-called front-line workers. This article reports an analysis of this method in order to provide a broader understanding of how the discourse on preventing violent extremism meanders from political and policy discourses into claims about how to organize educational practices and social work and the regulations under which these institutions operate. The results show that the CC contributes to a securitization of the educational system in ways that are not in line with educational traditions of schools in Sweden, or with the laws and policies that regulate the educational system.     

Newly qualified teachers’ professional digital competence: implications for teacher education

The professional digital competence (PDC) of teachers is of growing importance in classrooms, now that digital resources and digital media are becoming important parts of teachers’ everyday practice. This study explores how newly qualified teachers are prepared to use information and communication technology (ICT) in their initial teacher education (ITE). We present findings of a nationwide survey in Norway on 356 newly qualified teachers. It explores how these teachers’ ICT self-efficacy is related to how they perceive the quality of, and contributions from, their ITE related to ICT and the development of their PDC. In general, newly qualified teachers report fairly poor quality and contribution of ICT training during their teacher education. We claim that continuous effort is needed to review the quality of ITE and contribute specifically to the development of PDC and developing student teachers’ ICT self-efficacy in ITE.