Training of Athletes Before Competition with the use of VR base method


Abstract

The Technology of virtual reality (VR) has been employed to various field for different purposes. In sport training, as a strong alternation of traditional video-based method, VR-based method is better at providing three-dimensional display in environment simulation as well as effective auditory as external anxiety and precise analysis system. It could be used to not only analyze the impact of each factor on the overall performance of athletes but also improve their performance. In the first section, the visual effect of VR-based method and related experiment would be discussed. The second section would focus on the relationships between its built-in auditory system and competition anxiety. And lastly, its analysis system will be presented by how effective it is in improving the performance of athletes. Followed by that, the common concern of the implementation of VR-based method in terms of its cost and complexity will be further expanded to its promising future.

Keywords: VR, sport training, athlete, competition, simulation


The Technology of virtual reality (VR) has been employed to various field for different purposes, such as rehabilitation, gaming, physical education and so on. sport training is one of the potential field that could be investigated. Compared to traditional video-based method used in sport training,VR-based method is an ideal addition in sport training. It provides excellent real environment simulation together with auditory system and its built-in analysis system could examine precise measurement of the subjects in animation in order to enhance the performance of athletes. In traditional sport training, video-based method is employed by recording the performance of athletes with cameras in order to track the details in their gestures. According to Vignais et al. (2014), “the amount of visual information presented to participants is temporally controlled by cutting off the video clip at different key moments of the action” (p. 3). For example, in handball, cutting off the video clips at the moment when the ball is released from the hand of the thrower or when the ball is caught by the goalkeeper. However, in this traditional method, there are several limitations. Firstly, the viewpoints of subjects are based on the angles and positions of the camera, which is not optimal when analyzing the gestures and movement of the athletes (Vignais et al., 2014). Secondly, the “two-dimensional display of the video projection. With this method, the subject cannot extract stereoscopic information, as in real life” as Vignais et al (2014) explains. That means, when an athlete is performing a task, the video clips could only display the athlete in a flat projection, without stereoscopic depth information. For example, in handball, when a ball is falling off in the air, it could not tell by the video clips how accurate the athlete catches the ball or anticipate where the ball is going to land on. Due to these limitations of this method, applying video-based method in sport training is not ideal for improving the performance of athletes. However, VR-based method could overcome these limitations by simulating the real environment into the VR system and provide a real-time perspective when analyzing the performances of athletes.

Figure 1. Zhang, J (Dec 2017). Video-based method and VR-based method in capturing the handball thrower. [Screenshot]. Retrieved from http://www.sciencedirect.com/science/article/pii/S0167945714001833

In a contact sports that emphasize on interactions with players, like handball, soccer or basketball, they require various skills from an athlete in order to obtain maximal performance. In handball, for example, after the teammate passes the ball to the athlete and before the athlete gets the ball, he or she needs to perceive the visual information of an upcoming ball, using depth perception to predict where the ball is going to land on and make fast movement toward the ball which involve eye-hand-body coordination. When athlete catches the ball passed from the teammate, he or she needs to make immediate decisions of passing the ball to the teammates or score a goal. In contact sport event, the athlete needs to obtain good visual perception for moving objects, flexible eye-hand-body coordination, fast mobility, certain strength and more in a sequence within a short time. For these reasons, training integrated in the daily routine of athletes are essential as constant practice creates muscle memory for the athlete to performance the whole sequence with fluency and without conscious efforts. This could reduce mistakes during the task and focus on the ongoing situation.

In the role of the alternation in sport training, VR-based method is prominent in recreating a real-life environment with various environmental conditions in order to train the weather acclimatization of the athletes. With its built-in animation system together with motion capture system composed of numerous infrared cameras, the movement of the athletes are recorded. In sport training, it is essential that athletes are trained under different environmental conditions as different external factors could affect athletes’ performance. Wind speed, rain, temperature, humidity or air quality could all have a huge impact on athletes’ performance during competition. Study has found that heat acclimation can improve aerobic exercise in cool weather (Lorenzo, 2010). As Lorenzo (2010) states, “The cyclists who were heat acclimated performed anywhere from 4 to 8 percent better than they had before they trained in the heat, while the control group (completed the same training but in a cooled laboratory) did not improve at all” (p. 5). With the implementation of VR, it could recreate different environmental conditions to the athlete for training purpose as well as simulating various weather conditions for them to improve their weather acclimatization. It could turn the field into an outdoor basketball court in a sunny day with a designated high temperature or an indoor field with high humidity. According to Zorowitz (n.d.), as Bailenson explains, “VR is a constant technological system that tracks body movement and updates the sights, sounds and touch based on those movements; you feel like you’re mentally transported into a different place” (p. 7). In this immersive environment, VR could mimic all the possible situations that could happen during a real competition and bring it into training routine for the purpose of preventing potential mistakes or reinforcing their accuracy of decision making in different scenarios in a way to enhance their optimal performance. In particular, in handball, the body weight of the opponent team, their strength, running speed, running directions or gesture of holding the ball could all be manipulated by the VR technology using its built-in animation systems and sensors to generate haptic feelings to the athletes from hitting the opponent or the ball. In addition, VR provides a three-dimensional projection in virtual training field which imitate real environment as well as generate human-like figures to create real feelings as they were in real game. Research indicates that the handball goalkeeper’s movements in the virtual environment were similar to those captured in the real experiment, thus it could be used in sport training (Kulpa et al. 2003). Authors have conducted an experiment by asking one goalkeeper to stop 24 throws that were randomly assigned to him from three different types of throws, 6 m throw without jumping, 6 m throw while jumping, 9m throw without jumping. The goal of the experiment is to verify if the movement performed by the goalkeeper in virtual environment are similar to the one in real environment. By controlling the trajectories and shape of the ball same as real situation and comparing the arm and leg displacement of the goalkeeper in order to analyze his movement when performing the task, they found out the worst difference was about 11.9% for the arm motion. They concluded the movement of the goalkeeper react in both virtual and real environment were similar, which means the simulation of the virtual ball is succeed in mimicking the real game. Other than this, they found out VR could be used as a tool for athlete performance investigation. During the process, they notice the goalkeeper had made repeated mistake when intercepting the virtual ball, which demonstrates he anticipated the ball by observing the motion of the thrower instead of the trajectory of the ball (Kulpa et al. 2003). In sport training, VR-based method provides immersive environment by simulating real environment in addition to subjects in a sport game with its accurate measurements, which is succeed in making athletes perform similarly as performing in real environment. In addition, the environmental conditions together with weather or climate could be manipulated in VR-based method. For these reasons, the immersive environment simulated by VR-based method could provide various environmental conditions to athletes, and it does not affect their performance in real environment.

Figure 2. Thiry, L (May 2016). A pitch is delivered on the virtual reality simulator that is being used by teams in the majors. [Digital image]. Retrieved from http://www.latimes.com/sports/mlb/la-sp-baseball-virtual-reality-20160508-story.html

Not only does VR-based method provides an immersive three-dimensional visual for the athlete, it also contains effective auditory system as external anxiety to improve their performances during training. By simulating sound effect of audience cheering or any possible external factors that could potentially bring in competition anxiety of athletes also helps to make progress in their performances. During competition, audience noise, expectations from public or athlete themselves or any noises happening in the field could trigger competition anxiety depending on their psychological states. Athletes must learn to cope with the way that crow noise dominates the overall atmosphere in the field. With some amount of competition anxiety, it could elicit the improvement of performance, however, some could lead to athlete burnout. Research has defined athlete burnout as “support to Raedeke’s (1997) definition of athlete burnout as a syndrome characterized by: (i) emotional and physical exhaustion; (ii) sport devaluation; and (iii) a reduced sense of accomplishment” (Lonsdale, Hodge & Rose, 2009). In order to balance psychological states of the athletes, training with some amount of stress or pressure allows them to accustom to the actual field with noises during real competition. In VR-based method, crowd noise could be implemented in the systems in order to create the real competition setting and trigger anxiety to maximize the performance of the athletes. Recent research has analyzed “whether changes in the environment are able to induce changes in user performance, physiological responses, and the subjective perception of the task” (Sanz, Multon & Lécuyer, 2015). To minimize biased physiological recordings, Sanz, Multon and Lécuyer choose a 10m Olympic pistol shooting which does not require physical activity and design an experiment in two scenarios, competition and training. In both settings, participants were asked to perform two series of 30 shots per each condition and fill a questionnaire of their impressions afterward. With the data collected from the experiments and questionnaire, they found out that performance and physiological measures were the same for the two conditions (Sanz, Multon & Lécuyer, 2015). This interprets that the same stress and pressure could be created to training before competition, which allows athletes to experience the competition scenario in order to be mentally and physically prepared. According to Sanz, Multon and Lécuyer (2015), in competition condition, there were frustration and stress when the participant need to “(1) compete against virtual avatars and (2) deal with an aggressive audience” (p.49). For example, “some participants were annoyed by the audience (‘It was annoying when the audience was laughing at me.’) while others were annoyed with the behavior of other avatars (‘I could perceive my neighbor and I felt annoyed when she took too much time to shoot.’)” (p. 49). With the utilization of VR-based method in sport training, athletes are asked to leave their comfort zones and train under stress and pressure which keep them close to the situation in real competition. The auditory systems of VR serve as the external anxiety or pressure triggers and could be controlled in order to force athletes out of the comfort zone and bring out the potential of athletes’ performance. In other word, VR brings training in real competition.

Figure 3. Argelaguet, F (2017). 10m Olympic pistol shooting in VR[Digital image]. Retrieved from http://www.undefinedsymbol.net/node/124
Figure 4. Frontiers Medias SA (n.d.). side view of 10m Olympic pistol shooting in VR[Digital image]. Retrieved from https://www.frontiersin.org/articles/10.3389/frobt.2015.00010/full

Furthermore, compared to the tradition video-based method, what makes VR remarkable is its analysis system. In video-based method, two-dimensional information is limited to analyze the gesture or motion of the athletes, however, VR is able to address this limitation by analyzing performance of the athlete in three-dimensional space and provide precise measurements on each parameter. As Reilly (2015) explains, in baseball, the accuracy of hitting the ball mostly depends on the decision-making by the athlete, how he or she perceives the visual information of the ball being released and delivered and times up with its position instead of the movement of the ball itself. In VR-based method, all the movements of the subjects including the ball and athletes are being tracked in real-time. In particular, research has suggested in handball goalkeeper system, the percentage of correct zone, correct response, radial error, response time of the goalkeeper could be measured and further used as a tool to investigate visual perception in sport that involves interceptive tasks (Vignais et al., 2014). To make comparisons between video and VR-based method, an experiment of examining the efficiency of investigating visual perception of handball goalkeeper has been conducted. In the first place, A handball thrower is asked to throw a ball to the six lateral zones with five repetitions per zone for accuracy and the total of thirty throws are recorded by video camera and generated by animation engine in virtual environment simultaneously. Followed by that, the video clips and VR projections are being displayed for the goalkeeper to first make anticipation of the ball landing and intercept it. As a result, researchers have discovered that VR-based method is more efficient in investigating the visual perceptions of the goalkeeper by providing precise measurements between the ball and the goalkeeper. In its analysis system, with the motion capture system, his limbs and the ball movement have been recorded respectively in real-time. When the goalkeeper has successfully stopped the moving ball in the air, by what means, the collision between his limbs and the ball is being detected. On the other hand, the measurement between these two subjects are being interpreted as radial error of how much the hand is away from the ball when the distance between two is the least. In this way of analyzing and digitalizing the athlete performance, it helps visualize the weakness of the athlete and design the best strategy in a way to reduce his or her weakness and improve performance. For these reasons, VR is more appropriate for analyzing the performance of athletes by measuring the impact of each parameter and develop a suitable training routine to maximize their potential in better performance.

Figure 5. VR World (March 2016). VR analysis system used in Baseball. [Digital image]. Retrieved from https://vrworld.com/2016/03/23/vr-becomes-professional-simulation-tool/
Figure 6. Zhang, J (Dec 2017). Installation of VR. [Screenshot]. Retrieved from http://www.sciencedirect.com/science/article/pii/S0304394004011462
Figure 7. Zhang, J (Dec 2017). The measurement of radial error in handball. [Screenshot]. Retrieved from http://www.sciencedirect.com/science/article/pii/S0167945714001833

Even though VR-based method is outstanding in visual, auditory and analyzing aspects, some would say there are also a few drawbacks for VR-based method due to its cost and complexity. The installation and set-up of the system are complicated that requires a number of steps to be done. The simulation of real environment requires numerous steps to generate and same as the human figure in animation, all the possible gestures of the figure need to be created beforehand. In VR-based method, all data need to be presented in the VR system in order to track the movement of athletes and further analyze the data, athletes are required to wear motion capture device to record their data. Other than that, it is also necessary for them to wear 3D glasses or VR headset for the displays. In sports that require physical activity, such as basketball, soccer or running, the weight of VR headset would affect the performance of athlete. The inconvenience of wearing a headset device during training and the heaviness could potentially decrease the movement and mobility of the athletes. In addition, due to the fact that the auditory feedback such as vibration, has to be real-time in order to be effective, the wire would present, which could restrict the movement of athlete in a way to disrupt their normal performance. Furthermore, the cost of VR is relatively high compared to video-based method, which has stopped people from considering about it. However, longer setup of VR is beneficial for more accurate measurement and more specific analysis, after digitalizing every factor that could potentially affect the performance of athlete, it could visualize the mistake that an athlete has made, and correct them to prevent potential injuries and enhance performance as a whole. In terms of the heavy VR headset, according to Vignais et al (2014), there are “active stereoscopic glasses are now as light and small as regular glasses” (p. 5). VR-based method in sport training is an innovated method that is still under development, nevertheless, it is a technology that could bring in lots of potentials in the future. As Liao (2015) states, “VR was first used in the virtual reality systems for balance training, including a stationary bike and a flat panel display supplying visual virtual environment” (p. 5). The success of the employment of VR in the field of rehabilitation presents a promising future of VR-based method in sport training.

Figure 8. Pioneers.io (n.d.). Wires and Headset in VR Installation. [Digital image]. Retrieved from https://pioneers.io/blog/post/sport-vr

In conclusion, compared to traditional video-based method, VR method provides a better visual information together with effective auditory system, which lead to more explicit analysis reports on the performance of athlete. VR-based method is an strong alternation in sport training as the stereoscopic visual information, auditory as well as analysis system help to improve the performance of athletes. VR-based method is prominent in simulating real environment and recreate different environmental conditions for training the weather acclimatization ability of athlete. It has been verified that the training in VR-based method would not affect the performance of athlete in real environment due to its outstanding real environment imitation. In addition, its auditory system acts as external feedback has accustomed athletes to training under stress which is close to the situation in real competition. This forces athletes to train out of their comfort zones and bring out their potentials. Furthermore, the analysis system in VR-based method gives specific data of each gesture from athletes in order to evaluate the impact of each factor on the performance of athlete as a whole. According to an interview that Reilly has done with CNBC, after doing studies with elite athletes to junior high school kids, they have observed and examined the data over a period of time and noticed up to 30% of the improvement in decision making (Reilly, 2015). Due to the fact that in sport, good decision making is one of the fundamental skills that an athlete requires for maximal performance. With the constant practice in VR-based method, it would significantly improve all the relative skills in sports. In spite of the limitations of VR-based method, it is a new technology that worth investment and has promising future as it could not only prevent injuries in sports by correcting the motion or gestures of the athlete, but also improve their performance. As Liao (2015) states, VR based method could bring another technological revolution in sports, “Especially in the field of sports technique analysis, virtual reality technology indicates the transformation of human movement measurement from traditional eye-based observation to the capture and analysis of high-precision motion” (p. 8). Eye-based observation indicates video-based method which there is no depth information while VR-based method not only captures and provides three-dimensional display but also analyzes motions in sports. In short, VR-based method is an excellent alternation in sport training other than the traditional video-based method.

Reference

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