What a World Cup player really wears on their body

When you watch a World Cup match and wonder why some players briefly reach beneath their shirts at half-time, there is a system behind it. The so-called GPS vest is a close-fitting compression garment with a small sensor inserted between the shoulder blades. The sensor is around the size of a thumb, weighs 50–80 grams and delivers data at a density that is hard to imagine: up to 1,250 data points per second.

The device combines GPS signals for position data with an IMU (inertial measurement unit) – an accelerometer and gyroscope in one. Many systems also measure heart rate directly through the skin. The result is a complete movement profile showing where a player was on the pitch, how fast they were moving and how their heart was beating throughout.

The market leaders are Catapult (used by Bayern Munich, Chelsea, Real Madrid and more than 3,200 teams worldwide) and STATSports (official supplier to, among others, US Soccer, PSG, Juventus and the Brazilian national team). STATSports is the only system certified as a standard for accuracy, reliability and consistency following a four-year FIFA study.

What the coach sees on their tablet may sound dry, but in a match context it is remarkably detailed: total distance in km, current and maximum speed, number and quality of sprints, so-called high-speed running shares (>19.8 km/h), real-time heart rate, accelerations and decelerations. All live. All during the match.

For a long time, GPS vests occupied a grey area. They have only been officially permitted since February 2015 by the IFAB (International Football Association Board), and since March 2018 coaches have even been allowed to receive the data live during a match. Before that, the vest had to be handed over at half-time.

FIFA runs its own certification scheme, the FIFA Quality Programme for EPTS (Electronic Performance and Tracking Systems). It was expanded to include performance testing in 2019, and since 2023 it has also applied to wearables worn on the lower leg. Systems that are not certified may not be used in competitive matches.

There are clear restrictions: no physical receiving devices are permitted in the technical area – coaches receive the data on a laptop or tablet in the dressing room, not at the touchline. Brand logos on the device must also be covered while it is worn. The data itself may not be passed on to third parties, such as betting providers – data protection is a genuine factor here.

Beneath the GPS vest, some professionals also wear a close-fitting baselayer shirt and short tights. It is fair to ask whether this really helps or simply looks good. The answer is nuanced. Brands such as adidas call products like these Techfit: they fit close to the body, wick away sweat and provide a secure feel. It is fair to ask whether this really helps.

For materials, the professional game relies on polyester-spandex blends (moisture-wicking and quick-drying) or highly elastic nylon. Flatlock seams and seamless constructions prevent chafing during intense movement, which is particularly relevant for tackles or contact with the ground. The GPS vest is worn as an additional layer over the compression shirt, with the sensor pod positioned directly over the spine.

When no GPS vest is worn in matches, compression clothing also offers protection: it helps guard against abrasions and keeps muscles close to the body, a practical benefit especially for players involved in frequent challenges.

The 2026 World Cup in the USA, Canada and Mexico will open up a new dimension, not only because of its 48 teams but also because of the density of data. In collaboration with Lenovo, FIFA has launched the "Football AI" project, taking data capture to a new level.

Skeletal tracking is the core element: all 1,248 players are 3D-scanned in around one second and reconstructed as volumetric avatars. The system records 172 million data points per match, around three times more than before. Cameras operating at 25 frames per second provide precise real-time positional data for every player simultaneously.

Particularly interesting is the smart ball. The official match ball for the 2026 World Cup contains an integrated IMU that sends positional data 500 times per second. Goal or no goal, ball control, shooting angle and rotational speed can all be measured precisely. This takes goal-line technology to a new level of quality.

What the professionals wear cannot be transferred one-to-one to recreational players: GPS vests for amateur footballers are still niche products. But there are two takeaways you can use straight away.

First: compression clothing. The technology World Cup players wear under their vests has long been available through regular specialist retailers. Compression shorts and shirts also offer measurable recovery benefits in recreational sport, especially after intensive training sessions or matches. The price is far more accessible than it was five years ago.

Second: heart rate training. GPS data shows that professionals reach 85–98% of their maximum heart rate during a match. This is a useful benchmark for recreational players: training in this range realistically simulates match demands. A simple heart rate chest strap or armband makes this possible without FIFA certification.

What has not yet reached the recreational market is coming over the next few years: smart textiles. Compression clothing with woven-in sensors, including conductive yarns, biometric seam strips and graphene pressure sensors, already exists technically but has not yet reached the mass market. Manufacturers such as Adidas and Nike describe 2026 as a milestone for the first generation of consumer smart sportswear. Anyone wanting it today will pay specialist prices for technology that is not yet fully mature.

Conclusion: the trend is clearly moving towards measurable body data for everyone, but in this respect the 2026 World Cup player is still at least three to five years ahead of the recreational footballer.