Given how well Roger Federer had been playing at the U.S. Open, and given that he went into his quarterfinal with an unbeaten record against the guy he was facing, it’s not as if he needed any extra edge. Still, if Federer did want to employ a bit of gamesmanship, he could have tried to rattle his opponent by declining to participate in the usual on-court warmup.
Federer wasn’t going to do that when he played Grigor Dimitrov on Tuesday, of course.
But he could have.
Without any punishment.
That’s because, as Federer himself noted during an interview with The Associated Press this season, players are not required to take part in the five-minute pre-match warmup seen at every professional tennis tournament, Grand Slam or otherwise.
The mental change that has transformed Martin Ødegaard from lost talent to decisive playmaker resembles the one that helped Zlatan Ibrahimović step up his game.
The football goalkeeper position arguably represents a unique role within the team sport. Despite its highly complex skill demands, research on football goalkeeping has only sporadically examined the position within isolated and limited parameters. In particular, there is limited literature on “modern” skill acquisition training methods and approaches within the field of goalkeeper training. In a cross-cultural study with fifteen expert goalkeeper coaches, researchers here examined the overarching research question of “how does the modern football goalkeeper train?”. Semi-structured interviews explored expert coaches’ views on critical skills for performance in goalkeeping and the training approaches used to develop these critical skills. Results indicate that four skill sets are considered essential by goalkeeper coaches, these are: decision-making skills, athleticism, mentality, and technical skills. In terms of developing these skills in goalkeeper-specific training, the majority of expert coaches apply a similar microstructure to training sessions. This structure involves a steady progression from simple to complex training tasks, where for large parts, isolated technical training appears to be prioritised over a holistic training approach that integrates technical skills and perceptual-cognitive components (e.g., decision making). Scientific and practical recommendations for researchers and practitioners in the field of football goalkeeper coaching are provided.
… One of the factors associated with an increase in the risk of injury, is having low strength levels or significant muscle imbalance (for example, having a greater flexion strength rather than knee extension). In fact, the highest incidence of hamstring injuries has been shown to occur during the second half of a match, when the muscles are fatigued and generate lower strength levels. Thus, it is best to assess athletes’ hamstring strength after matches throughout the season to understand which athletes reach higher levels of fatigue and/or residual muscle damage, which could lead to a greater risk of injury.
Traditionally, the most accurate method for evaluating knee flexion strength (that is, of the hamstring muscle) has been by using complex dynamometers. However, in recent years, a very useful isometric strength test of the posterior chain, known as the McCall test.
PLOS One; Valerio Lorenzoni, Jacob Staley, Thierry Marchant, Kelsey E. Onderdijk, Pieter-Jan Maes, Marc Leman from
In this study, we assumed that correct functional movements for weightlifting can be learned with the help of a music-based biofeedback system. We compared musical feedback with verbal feedback from experienced trainers using two independent groups. The focus was on one specific movement called deadlift. Physical parameters under considerations were the spine (i.e. loss of midline stability resulting in flexion) and the forward displacement of the barbell during the repetitions relative to the mid-foot. We recruited 31 recreational weight lifters (21-42 years of age). Results revealed that both feedback types are effective in improving the movements for deadlift. No significant differences were found across the two feedback types, neither in terms of movement, nor in terms of clarity and motivation. The results suggest that the proposed feedback system is a valid tool for technology-aided training and self-training practices. [full text]
Background: In recent years, many studies have associated sedentary behavior in front of screens with health problems in infants, children, and adolescents. Yet options for exergaming—playing video games that require rigorous physical exercise—seem to fall short of the physical activity levels recommended by the World Health Organization.
Objective: The purpose of this study was to investigate the effect of a fully immersive virtual reality (VR)-based training system on cardiovascular and muscular parameters of young adults.
Methods: A cross-sectional experiment design was used to analyze muscle activity (surface electromyography), heart rate, perceived exertion (RPE), cybersickness symptoms, perceived workload, and physical activity enjoyment (PACES) in 33 participants performing two 5-minute flights on a new training device.
Results: Participants’ performance of the planking position required to play the game resulted in moderate aerobic intensity (108 [SD 18.69] bpm). Due to the mainly isometric contraction of the dorsal muscle chain (with a mean activation between 20.6% [SD 10.57] and 26.7% [SD 17.39] maximum voluntary isometric contraction), participants described the exercise as a moderate to vigorous activity (RPE 14.6 [SD 1.82]). The majority reported that they enjoyed the exercise (PACES 3.74 [SD 0.16]). However, six participants had to drop out because of cybersickness symptoms and two because of muscle pain due to prior injuries.
Conclusions: Our findings suggest that fully immersive VR training systems can contribute to muscle-strengthening activities for healthy users. However, the dropout rate highlights the need for technological improvements in both software and hardware. In prevention and therapy, movement quality is a fundamental part of providing effective resistance training that benefits health. Exergaming on a regular basis has the potential to develop strong muscles and a healthy back. It is essential that future VR-based training systems take into account the recommendations of sport and exercise science.
One of the popular applications for machine learning is object detection. Objection detection models can identify a wide variety of real-world items in standard photos or video feeds. Last year, we featured a traffic-counting device built using OpenDataCam running on an NVIDIA Jetson TX2. Now the software has been upgraded to version 2.0, and that introduces a handful of handy new features.
Suicidal thinking, severe depression and rates of self-injury among U.S. college students more than doubled over less than a decade, a nationwide study suggests.
Looking at data from two large annual surveys of college undergraduates covering the years 2007-2018, researchers found a broad worsening of mental health indicators including depression overall, anxiety, low flourishing and suicidal planning and attempts, particularly in the second half of the study period.
“It suggests that something is seriously wrong in the lives of young people and that whatever went wrong seemed to happen around 2012, or 2013,” said study coauthor Jean Twenge. She noted that this was around the time smartphones became common and social media moved from being optional to mandatory among youngsters.
International Journal of Computer Science in Sport from
The purpose of the present study was to demonstrate an inductive approach for dynamically modelling sport-related injuries with a probabilistic graphical model. Dynamic Bayesian Network (DBN), a well-known machine learning method, was employed to illustrate how sport practitioners could utilize a simulatory environment to augment the training management process. 23 University of Iowa female student-athletes (from 3 undisclosed teams) were regularly monitored with common athlete monitoring technologies, throughout the 2016 competitive season, as a part of their routine health and well-being surveillance. The presented work investigated the ability of these technologies to model injury occurrences in a dynamic, temporal dimension. To verify validity, DBN model accuracy was compared with the performance of its static counterpart. After 3 rounds of 5-fold cross-validation, resultant DBN mean accuracy surpassed naïve baseline threshold whereas static Bayesian network did not achieve baseline accuracy. Conclusive DBN suggested subjectively-reported stress two days prior, subjective internal perceived exertions one day prior, direct current potential and sympathetic tone the day of, as the most impactful towards injury manifestation.
The purpose of this study was to evaluate the existence of relative age effects (RAEs) in collegiate soccer. In addition, the impact of nationality, position, class, and National Collegiate Athletic Association (NCAA) tournament qualification status on the prevalence of RAEs was assessed. Birth dates from male NCAA Division I soccer athletes (n = 4,082) from the 2017/2018 season were categorized into quarters based on calendar and scholastic quarters. All athlete birth-date distributions were compared with the expected birth-date distributions for the United States. International-born athletes (INT) displayed a significant difference in birth-date distribution when assessed with calendar quarters, whereas American-born athletes (USA) showed a significant difference in birth-date distributions when assessed with scholastic quarters. Furthermore, INT showed significant RAEs for midfielders and defenders, whereas USA showed significant RAEs midfielders and goalkeepers. In terms of class, INT had significant RAEs for all classes, whereas USA had significant RAEs only for freshmen and sophomores. All INT had significant RAEs regardless of tournament qualification status; however, USA had significant RAEs only for nontournament teams. In summary, significant RAEs exist in male Division I college soccer; however, the presence of RAEs is influenced by nationality, position, class, and NCAA tournament qualification status. Coaches should be aware of RAEs during the recruitment process to avoid potential selection bias.
… The Relative Age Effect is a term used to describe how those born early in the academic year tend to perform to a higher level than those born later. This disadvantage may occur because those who are older are typically more physically, emotionally or cognitively developed than those who are younger.
For example, consider two different five-year-old children. One is born in September and is the eldest in the year – the other is born in August and is the youngest in their school year. Despite being in the exact same year group, the first child at this stage is almost 20% older than the latter. This means that they may appear from the outside as smarter, more advanced or more “naturally talented”, but the reality is that they are just older.
arXiv, Physics > Physics and Society; Victor Martins Maimone, Taha Yasseri from
Football is a major sport with worldwide popularity. In recent years excessive monetization of the game has been argued to have affected the quality of the match in different ways. In one hand playing football has become a high income profession and the players are highly motivated to perform well; on the other hand stronger teams have higher income and therefore they can afford better and more expensive players leading to even stronger appearance in tournaments that can make the game more imbalanced and hence predictable. In this work we take a data-heavy network science approach to measure predictability of football over 26 years in major European leagues. We benchmark our model against betting house predictions and after establishing its robustness we show that over time, the games in major leagues have become more predictable. We provide further support for this observation by showing that inequality between teams has increased in accord with the trends in predictability and the home field advantage has been vanishing ubiquitously. This is a first attempt to study football at a large scale and within a historical framework.
Powering international trade is the idea of “comparative advantage”: a country benefits by concentrating on the commodity that it can produce most efficiently, exporting this good, and then using the proceeds to buy in the commodities it is less efficient at producing. Even if another country is more efficient all-round and can produce everything at a lower cost, there are still benefits from trading.
A UEFA study of the Champions League last season suggests speed was a key to Liverpool’s title-winning campaign.
Analyzing all 366 goals in the competition, UEFA praised Liverpool for “pace and directness when attacking the opposition” en route to the club’s sixth European title.
Liverpool’s 24 goals took an average of just 7.81 seconds possessing the ball and 2.51 passes. The overall average for 32 teams’ goals was 12.5 seconds and 3.89 passes.