After the final whistle, many soccer players take off their shirts, either to exchange with their opponents or as a gift to a fan. From a few years ago, one thing draws attention right now: athletes wear a vest under their uniform. This accessory, in fact, is just a small part of the technological side of the sport – which even includes smart rings.
The vest has a device that has GPS, accelerometer and gyroscope. He collects important information for the coaching staff.
“This allows us to know what the athlete does on the field in terms of movement. We can also see the issues of acceleration, braking, jumps and turns”, explains Daniel Gonçalves, scientific coordinator of Palmeiras, in an interview with Technoblog🇧🇷
In addition to the total displacement data, the distances traveled in some parameters. In terms of speed, there are tracks above 19.8 km/h and above 25 km/h, which give an idea of the distance traveled at high intensity.
In accelerations and decelerations, there are categories above 2, 3 or 4 m/s². “This gives us parameters of resistance, strength and speed”, explains the scientific coordinator of Palmeiras.
Gonçalves also comments that there are reasons to put the device on the vest and not elsewhere. “Scientific studies show that accelerometry data are less impacted in this position. Therefore, it has greater reliability, reproducibility and validity.”
beyond the cameras
The use of vests with GPS in football began around 2014. Since then, alternatives have emerged that do not require the use of such equipment.
This is the case of LaLiga Tech’s Mediacoach. LaLiga is the sports association of clubs in the first and second division of the Spanish league.
The system uses 16 cameras in stadiums, which capture athletes’ movements at 25 frames per second. The technology is used by teams and also by sports broadcasts.
“In Spain, thanks to LaLiga Tech’s Mediacoach, which collects some of this data during games, many clubs don’t use GPS in competition,” explains Fabio Nevado, PhD in sports science who works in LaLiga’s research area.
Even so, cameras have limitations and do not completely replace the vest. “The GPS can offer more data than our system, in terms of heart rate, impacts, metabolic energy data”, adds Nevado.
By having a wider range of data, even Spanish clubs continue to use GPS during training. This allows you to better prepare each of the players.
Technology helps in training
Devices are useful for assessing how matches went, but they also play an important role in preparation.
“Player load is a good indicator in terms of injury risk, so the coaching staff analyze all the data to design training sessions and game plan knowing as much as they can”, explains Nevado.
Devices in players’ vests transmit data via telemetry and Bluetooth, and software makes the information accessible to coaching staff, who can make changes immediately.
“The data is interpreted in real time. They can be used to change the training or ask the athlete to change his behavior”, says Gonçalves.
The scientific coordinator at Palmeiras explains that speed, acceleration and braking data are correlated with other physical and physiological data.
Thus, it is possible to see how the player is recovering from an injury or adapting to a training session. Depending on the data, the coaching staff can reduce the load to prevent further medical problems or increase it to speed recovery.
One of these data is heart rate, which is also tracked by equipment used by players. “An athlete can cover the same distance as another, but training can be more exhausting for one than for another”, says Gonçalves.
Nevado also mentions injury history, physical exams, medical information, eating habits and sleep quality. “Every bit of information is helpful, but it’s up to each club to prioritize what information they look at.”
Rings in the Cup
During the 2022 World Cup, the players of the Brazilian National Team will use the Oura Ring, smart ring with sensors similar to those of a smartwatch. The idea is to monitor the sleep and rest of athletes between matches.
The most frequently called up players took the device to use on a daily basis. Manchester United’s Fred said the Globe Sports that this helps you monitor the quality of your sleep and maintain a more disciplined routine.
The Oura Ring was also used in another sport: basketball. In 2020, months after the start of the pandemic, the NBA took part of the teams to Orlando (USA), where they were isolated and participated in a tournament to end the season. Players wore these rings as a way to monitor possible symptoms of COVID-19.
What about smartwatches? When they first appeared, they promised to replace smartphones. Over time, however, this type of product ended up turning to the areas of health and sports. Some, such as the Apple Watch, watches aimed at runners and Mi Band bracelets, have become popular among those who practice physical activity as a hobby.
In high-level competitions, this type of device does not always have space. Nevado, from LaLiga, considers that they are neither enough nor quite accurate enough to be adopted.
“The players’ physical activity is recorded by the club in training, and the rest of the day we assume that the player is focused on rest and not on high-demand activities, so these types of devices are not that useful”, says the LaLiga researcher .
Gonçalves, on the other hand, considers that rings and bracelets are interesting for monitoring sleep, energy expenditure and recovery levels. And there are even more specific devices, such as shirts, shin guards and cleats, to monitor how the athlete’s body reacts to the demands of the sport.
Data help, but the technician decides
The data collected by the equipment helps even during matches.
“Some physical data even consider making decisions to make a substitution or not”, explains Nevado, from LaLiga. With the load of the match, the coaching staff can assess the risk of injury and change a player to preserve him, for example.
Even with so many numbers involved, the process of scaling a team is far from automatic. The figure of the coach is essential to gather all this information, create strategies and take the best possible team to the field, even if this goes against the data.
“An athlete with a weakness in the physical aspects may, for that match in question, have some technical or mental quality that can be overcome and consequently be used in favor of the community”, observes Gonçalves. “There is advice for the coach, and the decision-making is his. The coach is always sovereign.”