Alcaraz, Sinner and Sabalenka: How Whoop Sparked Tennis’ Biggest 2026 Tech Debate

There are few things tennis loves more than tradition. Crisp whites. Polite applause. Suffering quietly.

What it loves considerably less? Athletes checking their recovery stats mid-match.

At this year’s Australian Open, a discreet black wristband has sparked one of the most quietly explosive tech debates elite sport has seen in years. The culprit: Whoop – a screenless wearable designed to track sleep, recovery, exertion and physiological stress.

The flashpoint came when world No.1 Carlos Alcaraz was ordered to remove his Whoop band moments before his fourth-round match in Melbourne. The device, concealed beneath his wrist sweatband, was spotted by chair umpire Marija Cicak during warm-up on Rod Laver Arena. Alcaraz complied without protest. The exchange aired globally. Tennis Twitter combusted.

And suddenly, the sport found itself arguing about cortisol.

“Data isn’t steroids”

Whoop founder and CEO Will Ahmed did not mince his words. “Ridiculous! Whoop is approved by the ITF for in-match use and poses no safety risk. Let athletes measure their bodies. Data isn’t steroids!” he wrote on X.

The irony? He’s not wrong – at least not on paper. Both the ATP and ITF list Whoop among approved wearable devices for in-match use. The WTA has allowed wearable tech since 2021. The ATP followed in 2024, with then chief sporting officer Ross Hutchins calling the decision a “big step forward in our push to optimise player performance and prevent injury”.

And yet, at Grand Slams – tennis’ most prestigious stages – different rules apply.

A Grand Slam exception

Despite being approved by the ITF, Whoop devices are currently prohibited at Grand Slams unless explicitly authorised by tournament organisers. The Australian Open confirmed the ban, citing longstanding concerns around in-match communication, coaching and betting.

At the centre of the resistance to wearables like Whoop is sport’s increasingly uneasy relationship with sports betting. Live biometric data – heart rate spikes, visible fatigue, stress indicators – could theoretically be interpreted by those with access as real-time insight into an athlete’s physical state, potentially influencing in-play betting markets. Tennis, more exposed than many sports due to its individual nature and extensive global betting volume, has long been sensitive to anything that could be perceived as conferring an informational edge.

Grand Slams, in particular, operate under stricter integrity frameworks designed to prevent even the appearance of impropriety, especially around live data transmission. While Whoop itself does not display data publicly during matches, tournament organisers remain cautious about any device capable of collecting or transmitting physiological information in real time.

Veteran commentator Mark Petchey explained it bluntly on broadcast, “You’re not allowed to play with a Whoop watch here or anything that monitors your vitals or anything else.” In other words: what’s allowed on tour becomes controversial the moment it steps onto a Grand Slam court. This contradiction has created a regulatory grey zone – one that players have now wandered into, knowingly or otherwise.

“Rules are rules”

Alcaraz, for his part, took the ruling with characteristic calm. “These are the tournament’s rules, the ATP’s, the ITF’s… You can’t play with it. It’s something that helps you take better care of yourself, to monitor your recovery, your training load… but well, I haven’t been able to use it in matches, it’s fine. You take it off and keep going,” he told reporters after reaching the quarterfinals.

That statement, however, contains a subtle inaccuracy. The ATP and ITF do permit Whoop. The ban came exclusively from the Australian Open. And Alcaraz wasn’t alone.

Sabalenka, Sinner – and a pattern emerges

World No.2 Aryna Sabalenka, a Whoop ambassador, faced the same issue in her opening match and was also instructed to remove the device before play.

In a WTA-published video following her 2024 US Open title run, Sabalenka openly explained how central Whoop data was to managing her performance:

“Well, I always check the [Whoop] app, when I wake up, after practice, and it’s really good to know your recovery and stress. It’s really cool that it has a stress monitor… if I see that my recovery is a little bit long, I do some extra treatments. It’s actually really good to have these kinds of stats on your body. Especially on the big tournaments when stress is quite high, and recovery is the key to maintaining all of this.”

Meanwhile, defending champion Jannik Sinner was also asked to remove a Whoop device before his fourth-round match. “The umpire asked me straightaway if this is the tracker. I said yes. He said remove. It’s fine… rules are rules. I understand. I won’t use it again,” Sinner said afterwards.

So why the resistance?

At the heart of the debate is a philosophical question tennis has been avoiding for years: how much information is too much information?

Whoop devices collect heart rate, heart-rate variability, blood oxygenation, respiratory rate, skin temperature, sleep stages and strain. The data syncs via Bluetooth – raising theoretical concerns about live communication.

But Whoop and the ITF have already addressed this. The device was approved following a review, provided haptic feedback is disabled during competition. In other elite sports – football, rugby, Formula 1 – biometric tracking is routine. Data is used to prevent injury, manage fatigue and identify when athletes are entering the “red zone”.

A WTA Performance Health team employee was open about this approach in the same video that featured Sabalenka, “The Whoop is gonna tell you sometimes… you’re in the red zone. The guidance from the Performance Health Team of the WTA is giving the right advice to the athletes. ‘Okay, you are in the red zone.
Now you need to take a day off or do active recovery’… The WTA players integrate these new technologies, like the Whoop, into their game, to optimise their performance.”

Tradition vs transparency

Tennis Australia has confirmed that wearables are “currently not permitted at Grand Slams”, adding that the tournament is “in discussions” about future changes.

There is also the equity argument: not all players have equal access to advanced tech. But in an era where tournaments already deploy high-tech camera systems to track distance covered, sprinting and load – and partner with companies like Bolt6 for electronic line calling – the line feels increasingly arbitrary.

As Whoop put it in an official statement, “Whoop believes athletes have a fundamental right to understand their own performance and health – including during competition at events like the Australian Open… Blocking access to personal health data does not protect sport.”

Ridiculous. Whoop is approved by the International Tennis Federation for in-match wear and poses no safety risk. Let the athletes measure their bodies. Data is not steroids! https://t.co/fC3JX6Vldm

— Will Ahmed (@willahmed) January 25, 2026

 

What this really says about modern sport

Strip away the wristbands and this becomes something bigger: a generational clash between instinct and information. For a new wave of athletes – particularly women, who have long had to advocate for their bodies to be taken seriously – data isn’t an advantage. It’s autonomy.

Knowing when you’re over-reaching. Understanding stress. Protecting longevity. The idea that tracking recovery could undermine the “purity” of competition feels increasingly outdated – especially in a sport that now openly embraces in-match coaching pods, analytics teams and AI-driven insights off-court.

Carlos Alcaraz still won. Sabalenka still dominates. Sinner still defends his title. If data isn’t steroids – and it isn’t – tennis may soon have to decide whether protecting the past is worth ignoring the future.