Yo-Yo Intermittent Recovery Test and its relationship with other field tests for footballers
Measurement is as important as the test chosen to do so. Not all tests assess the same parameters, which makes it difficult to choose the right one.
One can say that even if you have never tried out these technologies, it is likely that you know someone who has. You put on the “glasses” and then you’re transported somewhere else. Your body changes into something else or disappears altogether, and you feel as if you were living in a world created by a computer. You point your Smartphone towards a certain point and a character appears on the screen, interacting with the environment. Virtual reality, augmented reality and mixed reality are establishing themselves in a society which is becoming ever more accustomed to the use of new technologies for entertainment, consumption or information. Is there a place for these solutions in the world of sports?
Let’s explain the basics. Virtual reality (VR) is a computer-created environment – which makes use of glasses or a headset plus a combination of cameras and sensors, gloves, joysticks or suits – to transport you inside it. There are three types of illusions that play with our sense of perception within these environments: the illusion of being present in this new space is known as place illusion; the illusion in which we feel that the things that are happening are actually real is called plausibility illusion; lastly, not in all cases but rather for those in which we are given a virtual body, we feel that this body is actually ours thanks to the well-known effect known as embodiment. Thanks to a combination of these three illusions, we can feel a real sense of vertigo when leaning out over the edge of a virtual skyscraper, jump in fear at the sudden appearance of a terrifying character from behind a door, or embody a person of another gender, race or shape by way of simply blending in with a virtual body of a different type.
In contrast to this, augmented reality (AR) allows us to add computer-created data to a real environment, resulting in a hybrid mixture of computer-generated graphics and our reality. Pokemon Go would be an example of this type of solution.
Lastly, mixed reality (MR) is quite similar to AR, but with one fundamental difference: the virtually created objects and scenarios can interact with the real ones on a mobile phone screen or glasses specifically designed for this purpose. Magic Leap has become a reference in this field.
The sports world is aware of the importance of these technologies and, although tentatively, it has been taking steps towards taking advantage of these types of solutions for years now. Virtual reality’s ability to make you “feel like you’re in another place” is allowing NFL players to practice plays without having to be on the field and repeat them whenever necessary, in addition to training other areas such as managing pressure and stress during a match. A similar system is used in the Premier League for reaction time or short pass strength training in virtual or simulated matches. In fact, augmented reality and mixed reality work in solutions that allow the athlete to visualise the correct trajectory of the ball. Nobody can shy away the potential use of these technologies for athletes’ rehabilitation.
Silvia Ortega, research project coordinator within the physiotherapy area, believes that the use of virtual reality may yield interesting benefits in sports rehabilitation – namely lost performance during an injury period – but such potential gains are yet to be quantified. “We cannot confirm this because no evidence has been found in investigations carried out with amateur or elite athletes.” FC Barcelona’s physiotherapist believes that a possible obstacle to performing more studies in this area is currently due to technical limitations. “The instrumentation required for quantifying changes in the players at the level of the central nervous system is aggressive, and we are lacking still from scientific methodology for it.” On the other hand, in Silvia’s opinion augmented and mixed realities do have an important impact in terms of applicability: “I see them as technologies which are more geared towards the cognitive aspect of rehabilitation. Areas like decision making, the creation of a stressful environment or even acting as a mobile stimulus, all have their place in this type of solution.”
Would there also be a place for the use of these technologies in FC Barcelona’s methodology? Preparation of the club’s players is based on what is known as a structured microcycle. Devised by Paco Seirul·lo, this approach comprises a complete paradigm change, as it strays away from the training of individual abilities in an isolated manner anda focuses on the full observation of the individual. This way, the coaching staff can work on any aspects which may influence performance, prioritising qualitative factors over quantitative ones while not ignoring the natural uncertainty of the sport itself.
Isaac Guerrero, Technical Director of the FC Barcelona Football School, and member of the methodology and knowledge department at Barça Innovation Hub, explains the key benefits of a certain working method which has shifted this sport: “Our idea of a football game is tied to the values that the club itself represents: solidarity, cooperation… and always staging the game around the ball, which is already an important change compared to the classic paradigm.” The player has a greater interaction with the other players, bypassing the classic segmentation between attack and defence, allowing for every team member to cooperate and have a function at any given moment. “This results in a dynamic configuration in which there are no fixed positions.” Such complexity would call for great intelligence on behalf of the system for simulating all these requirements. “The objective is to create contexts which incite the player to organise and self-organise around the ball as if it were a centre of collective energy. This tactical experience is more communicative than it is tactical, it’s unable to be modulated or designed in advance, and it incorporates an important affective factor.” Do we have technical solutions which can currently achieve this level of elaboration? According to Isaac, “these systems that are based on control using a device (controller) by means of dominant limbs (i.e. arms/hands), do not appear to be significant. I have to be able to interact with every part of my body, namely perform coordinative implementation by means of my non-dominant limbs (i.e. legs/feet); as I move. This requires a distribution of my perception (and feeling) between the technical interaction with the ball and also the association and motor actions performed for moving through space”
This outstanding student of Paco Seirul·lo affirms that the ideal technological solution for Barça is still yet to arrive. “Among other requirements, the system should adapt to each player and take into account the abilities of a certain player with those of the other members of the team.” The option of obtaining efficient assertiveness as a result of virtual training would be another enormous achievement. “If you are to my left and I know that you usually dribble the ball to a certain side, I will end up assimilating this by way of specific training scenarios.” Unquestionably, however, Guerrero highlights, above all other necessities, the possibility of identifying all those subjective aspects which are usually forgotten in solutions typically centred on parameters such as the number of passes or ball control. The future is in the qualitative aspect: “A system which could recognise preferential behaviour would be quite interesting, as are what we call ‘groups of high empathetic resonance’, which link the assertive relationships that are established between players who, preferably, share the same space.”
And what information should be monitored from the point of view of the coaching team? “It would be a great advantage to take into account the emotional variables in players’ behaviour. The head coach states it clearly: “Recognising the interests, requirements, feelings and emotions of other team members is the future of these systems.”
Many current requirements still lack a real solution and may lead one to reflect on the suitability of using these technologies within a sports environment. According to Raúl Peláez, Head of Sports Technology, Innovation and Analysis for FC Barcelona, virtual reality is very promising – but it will never be able to compete with reality. “If we have two hours available on the field, we prefer to be there with all the complex experiences that training is able to generate, as there are many things which get lost in any computer system, even if it is the most sophisticated technology.” The use of these technologies should, therefore, be complementary in nature and not meant to replace the methods we have been using until now. “Where I believe that the application of virtual reality would be most interesting is in specific cases or scenarios”, Raúl states. “When a youngster first arrives in the first team, it would be good for him to participate in a real match with the players. With the positional data that we have at present, we could reproduce, in detail, how the match would be played out. And no decision making would be required either.” A simulation that, according to Raúl, would produce the best results when the players and the scenario were as realistic as possible – so as to avoid the feeling of being in a video game.
Another possible use would be for goal kicks. “It’s difficult to work with the goalie on this because you need the other 21 players in place during the training session. For situations like this, in which you don’t have all the players available, it makes sense.” And what about AR and MR? “This is where I see the biggest potential. Video footage in football is a fundamental tool for any coach. It would be great to offer an experience allowing one to see things from all angles.” However, for the head of technology, it is necessary to know very well when to use these technologies and when not to. “Just as Zubizarreta explained to me, technology should be on the sideline looking outwards. In the field, there should be just the players and a ball”, he added. One should respect the legacy of this sport and not interfere. We should search elsewhere for new experiences that may add value to them.” So, in the near future will we see players training with glasses that allow them to experience these other realities? “No solution should have to make you put strange things on your eyes.” None at all? “Well, maybe some special contact lenses are designed in the future…”
It’s a long journey to develop solutions in virtual, augmented or mixed reality which is able to meet the expectations of users in this type of environment. The indispensable collaboration of all participants implied for its development – engineers, programmers, but also physiotherapists, technical staff and players – is the main ingredient for it to succeed. A type of system that maybe can end up causing a true revolution in the sports world.
The Barça Innovation Hub team
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