Why did Alcaraz, Sinner & Sabalenka have to remove fitness trackers?

Six-time Grand Slam champion Carlos Alcaraz was told to take off a fitness device before his Australian Open fourth-round match

Tracking technology can help monitor a person's sleep, strain, stress and heart health.

"Wearables provide meaningful insight into workload, recovery, injury prevention, and clinical evaluation," Dr Robby Sikka, medical director at the Professional Tennis Players Association, told to reporters.

"Like any technology, they have trade-offs, but the solution is education and consistent, science-based policy - not sudden bans without a comprehensive review applied equally to all players."

So why aren't players allowed to use wearables at the Slams?

The fragmented nature of tennis governance is one reason. The Australian Open is said to be pushing for the devices to be allowed at the majors, but a collective decision has not been signed off.

Another argument suggested to BBC Sport is the technology could provide a competitive advantage to elite players.

It is felt the stars have greater access to devices, which can cost up to £300, either through sponsorship deals or financial strength.

Another reason put forward - perhaps more plausibly - is difficulties surrounding data ownership and its commercialisation, as well as partnership deals with wearable firms.

The Australian Open says it provides some health data to players and their teams at the tournament.

"They can monitor key external load measures such as distance covered, changes of direction, high acceleration events and speed/spin of shots," it said.

The issue of player welfare has long been a hot topic in tennis, with fears some stars are reaching breaking point because of the physical and mental demands placed on them by a long, intense season.

Sports scientists have argued tennis falls behind other sports when it comes to data analysis.

Alcaraz, who has expressed fears the season is too demanding, Sinner and Sabalenka being instructed to remove their devices appears to support that view.

Stephen Smith, founder of Kitman Labs, says tennis must collect more data from its athletes in both practice and match conditions.

This information should be centralised and shared across the tours for the benefit of all professionals, he says.

"There is a huge opportunity for tennis to start understanding how you apply tech and data to improve player welfare," says Smith, whose company has provided Premier League football, Prem rugby and NFL teams with data and analytics.

"We've seen it work in other sports - particularly American sports like the NFL, NBA and MLB. The NFL are world leaders in this field.

"They've been collecting data across the demands of their games - training and games and the injuries - and making rule changes based off what has been happening."

Dr Sikka, who is also a team physician for baseball's New York Yankees, agrees.

"Other major sports leagues have already built thoughtful, evidence-based frameworks for wearable technology," he said.

"Tennis should meet that same standard."