How wearables are reshaping training

Before his fourth-round match at the 2026 Australian Open, Carlos Alcaraz heard chair umpire Marija Cicak ask him to remove something from under his wristband. It was a WHOOP, a screenless band that tracks heart rate, sleep, strain and recovery. The ATP, the WTA and the ITF had all approved the device for match play. The Australian Open had not. That gap between the tours and a Grand Slam captures where wearables stand in elite sport. Teams build training plans around the data every day, while the rulebooks for competition differ from one league to the next.

The business of wearables in team training

Catapult, the Australian athlete-monitoring company, gives a sense of the scale. In results for the year ending March 2026, the company reported more than 5,500 teams across 40 sports in over 100 countries, and it added 576 new pro teams during the year, Proactive reported. Revenue rose 19% to a record US$140.7 million. Its product line now runs from athlete monitoring to video analysis and scouting.

CEO Will Lopes called FY26 “a transformational year for Catapult.” The growth shows how many teams now pay for athlete monitoring. A related logic drives the optical systems leagues use on game day, which we cover in our look at the next era of player tracking.

Recovery data and the load management debate

Consumer-grade devices brought recovery tracking to individual players. When MLB cleared WHOOP for games in 2017, ESPN reported that the band measured sleep, recovery and strain and gathered about 100 megabytes of data per day. WHOOP founder Will Ahmed called it “Moneyball 2.0.”

Load management sits at the other end of the same question: when should a team hold a player out? The NBA answered part of it by rule. Its Player Participation Policy, which took effect in 2023-24, bars teams from resting multiple stars in one game without approval and from sitting healthy players in nationally televised or in-season tournament games, the Associated Press reported. A “star” means any All-NBA or All-Star pick from the previous three seasons. Penalties top $1 million once a team reaches three violations. A separate collective bargaining rule requires 65 games, in most cases, for awards such as MVP.

Celtics forward Jaylen Brown told the AP, “I’m trying to play as many games as I possibly can.” Heat guard Tyler Herro called the 65-game minimum “smart for the league, for the fans, for everybody.”

League rules on in-game wearables

Each league writes its own rules, and they differ.

• MLB approved WHOOP for in-game use in March 2017, the first major U.S. league to clear a continuous biometric monitor for competition, per ESPN. Teams cannot make players wear it.
• The NBA limited biometric monitors to practice under its collective bargaining agreement at the time of that ESPN report. The league told Matthew Dellavedova to stop after he wore a WHOOP in 13 games. In the 2020 Orlando bubble, the league ordered more than 2,000 Oura rings as part of its health protocol, Front Office Sports reported.
• Tennis splits by event. WHOOP has been a WTA partner since 2021, the ATP approved it in 2024, and the ITF approved it in 2025 as player analysis technology, provided players turn off haptic feedback and check data only when coaching is allowed, Tennis.com reported. The four Grand Slams set their own rules.

The Australian Open asked Alcaraz and world No. 1 Aryna Sabalenka to remove their bands. Organizers said wearables were not allowed at Grand Slams and that talks with WHOOP were ongoing. Players there could see external load data from tournament tech partner Bolt6, such as distance covered and shot speed, but not their heart rate during matches. Jannik Sinner, the two-time defending champion, said he would follow the rule.

“But rules are rules. I understand. I won’t use it again.”

Jannik Sinner, quoted by Tennis.com

In April 2026, Ahmed posted that the French Open, Wimbledon and the US Open would allow WHOOP in matches, The National reported. The National attributed that claim to Ahmed and noted it was unclear whether the Australian Open would change course.

Who owns athlete wearables data

The rules on data matter as much as the rules on devices. Under the MLB arrangement ESPN described in 2017, WHOOP held no rights to player data. Players and teams could analyze it equally, and any commercial use, such as a TV graphic, needed consent from both the player and the club. ESPN also noted that HIPAA did not cover biometric data, and that WHOOP offered 27 privacy settings so players could share some metrics and keep others private.

Ahmed framed the tennis fight as an athlete-rights issue. “Let the athletes measure their bodies. Data is not steroids,” he wrote on X, as The Nightly reported. The Nightly added that in-match coaching rules in tennis have loosened, which fuels the argument that limits on real-time data are out of date.

What wearables data could mean for fans

For now, most wearable data stays inside the team. The consent terms in MLB’s deal show why: a broadcaster needs both the player and the club to agree before biometric numbers reach your screen. Our technology coverage tracks how leagues handle that consent as devices spread.

Tennis offers a preview of what fans could see. At the 2026 Australian Open, tech partner Bolt6 supplied external load metrics such as distance covered, direction changes and shot speed. Those external numbers make good fuel for live debate in FansPulse game rooms, where fans and creators react to each point. Heart rate and recovery scores stay off the screen until players and tournaments agree to share them.