Thanks to its heart rate monitoring capabilities, the Apple Watch can determine if a person has COVID-19 a week before symptoms appear.

According to CBS News, a new medical study found that Apple's wearable and other flagship smartwatches can detect "subtle changes in an individual's heart rate" that indicate they may be infected with the coronavirus, even if they appear asymptomatic at the time.

The study, conducted by Mount Sinai Health, analyzed the ability of the Apple Watch to estimate heart rate variability by measuring intervals between heartbeats. The study involved 297 healthcare professionals wearing the device, and the focus group wore the Apple Watch for five consecutive months (April 29 to September 29).

The researchers concluded that COVID-positive individuals tended to have less time variability between heartbeats than COVID-negative individuals.

Rob Hirten, assistant professor at the Icahn School of Medicine at Mount Sinai in New York City, told CBS: "We already knew that heartbeat variability markers change when inflammation occurs in the body. That allows us to predict when an infected person is infected without realizing it."

Most importantly, he emphasized that the Apple Watch "can identify people who may be asymptomatic. This is a way to better control infections."

Another study conducted by Stanford University in California involved participants who wore not only the Apple Watch but also other known fitness trackers from brands such as Fitbit and Garmin. Stanford researchers suggested that 81% of participants who tested positive for COVID-19 had experienced changes in their resting heart rate up to 9.5 days before developing symptoms.

Experts hope that smartwatches will "play an important role in staving off pandemics and other infectious diseases."

Apple has not yet introduced the proper software that would allow everyday users to detect COVID-19 symptoms at a very early stage, but those eager to track their overall health can take advantage of other features Apple has introduced in the meantime.

With the introduction of watchOS 7.2 and iOS 14.3, Apple Watch users can now take advantage of one of the flagship wearable's most useful health-related features, Apple Watch Cardio Fitness.

This feature allows users to track their overall health through VO2 max, a metric that estimates the maximum amount of oxygen the body consumes on a daily basis. The update also allows users to improve their health by categorizing their personal fitness level and sharing advice on how to improve it.

If you want to get yourself a stellar wearable device to monitor your health, check out our picks for the best fitness trackers and best smartwatches.