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LEAWOOD, Kan. — Professional fitness trainer Christina Larson isn’t a doctor, but she likely knows more about her client’s health than most family physicians.

“I can know exactly how much food they had,” Larson explained while scrolling through screens on her iPhone. “So before their workout, I could back it off, or build it back on.”

Larson, owner of His and Hers Fitness in Leawood, keeps constant tabs on dozens of her clients using the Apple Health app on iPhones and Apple watches.

“Some of my clients are retired, so it’s helped them significantly, to be able to keep track of where they are on their activity level,” Larson told FOX4. 

Now, North Kansas City-based Cerner Corp. is taking the same concept and scaling it up.

“People want to do a better job of taking care of themselves, so they have things like your health apps and wearable tech,” Sam Lambson with Cerner said. “And you live with your health every day and you might only see your doctor once or twice a year.”

Cerner will partner with Apple to share users data with the next version of the ‘Health’ app in the iOS 15, which will be released in the fall.

“The ability to track these key metrics about your lifestyle, steps, your weight, even in some cases blood glucose and blood pressure, you can attach to these devices,” Lambson said.

The data sharing will be entirely voluntary, no one will be forced to opt in. But the goal is prevent some of deadliest, and most expensive, conditions, like heart disease and diabetes. If nothing else, for many, it could change the routine doctor visit forever.

“It will give doctors a better sense for how their patient’s lives are going between visits,” Lambson said. “To better manage their life, over time, rather than just when they see their doctor.”