Real Madrid players recently returned to the training ground with an unusual sight: many were wearing blue masks during high-intensity drills. This striking image, seen on 4/2 after their La Liga round 22 victory against Rayo Vallecano, quickly captured attention.

Real Madrid players wear blue masks during a training session on 4/2. Photo: Real Madrid FC

Several stars, including Trent Alexander-Arnold and Kylian Mbappe, posted photos of themselves training with masks on social media, further fueling fan curiosity about the device's purpose.

These aren't typical altitude training masks, but specialized Cosmed K5 devices, an initiative by Italian fitness expert Antonio Pintus. According to Real Madrid TV, the masks are designed to precisely determine each player's aerobic and anaerobic thresholds, alongside their current exercise capacity.

Pintus noted that players wear the masks for specific 15-20 minute stress tests. The technology allows coaching staff to accurately measure VO2 max – the maximum oxygen the body can absorb and utilize during intense physical activity. It also analyzes whether players are primarily burning fat or carbohydrates for energy, crucial for maintaining optimal physical conditioning as the season reaches its critical stage.

Real players wear blue masks during training on 4/2.

Sports physiotherapist Ben Warbuton, speaking on BBC, highlighted the innovation. While such masks are typically confined to controlled environments like treadmills or stationary bikes for fitness assessments, Real Madrid has adapted the technology for regular training sessions. "They possess high-tech equipment to both test and train simultaneously," Warbuton explained. "This is very beneficial for the coaching staff because they don't have to dedicate a separate session solely to fitness testing."

Traditional VO2 max tests often prove difficult to implement during the season due to their time-consuming nature and the risk of overload from different surfaces. "If the entire squad had to be tested one by one on a treadmill or bike, they would lose an entire training session," Warbuton analyzed. "Not to mention, the surface of a treadmill is completely different from grass, which can easily lead to overload." Integrating the masks into football-specific drills also helps reduce the risk of soft tissue injuries, ensuring the team gains important physical data without wasting valuable training time.

The collected data provides the coaching staff with a detailed assessment of each player's condition, enabling them to adjust training loads appropriately. "The results will show what fitness level a player is at," Warbuton stated. "They will compare it with that player's baseline data or with players in the same position. Those with lower VO2 max might need additional physical training."

Warbuton acknowledged the high cost of this technology, suggesting it may not be feasible for every club. For Real Madrid, however, optimizing player fitness is paramount as they face a demanding February schedule, including three La Liga matches against Valencia, Sociedad, and Osasuna, plus two Champions League play-off legs against Benfica. These upcoming fixtures are pivotal for Alvaro Arbeloa's team, potentially shaping the outcome of their season.

Hong Duy (via BBC)