Is Apple HealthKit Losing Data?

Apple's HealthKit platform, which gives developers the ability to tap into the health and fitness data its devices collect, is a big part of iOS 8. But this week, some users are reporting that their HealthKit data has been lost.

On Sunday, a user posted a report to the Apple Support Communities forum indicating that data being shared with the MyFitnessPal app had disappeared:

I went to bed last night and everything was tracking fine between my Healthkit app and myfitnesspal app. I had 5 or 6 things pinned to my dashboard. I woke up and it is all gone. Nothing is pinned to my dashboard and when I swipe to put it on my dashboard and press back it still isn't there and I go back in and it is switched off.

More than two dozen users responded, many reporting a similar experience. Other reports surfaced on Hacker News, lending credibility to the possibility that there's a more widespread problem. Apple's iOS 8.0.2 seems to be a common feature of many of the reports, suggesting that if an issue does exist, it may have been introduced in the updated version of Apple's mobile operating system.

An Apple support posting from Sept. 17 contains instructions for what users should do "if your Health data doesn't update," but it's not clear that this refers to the same issue being reported. One user suggested that performing a hard reset will resolve the problem, but that doesn't appear to be working for everybody. According to one Hacker News comment, "I've had to restart my phone four times so far and the data does seem to come back, but anything that was logged during the time it didn't work isn't there." Other users indicate that resets don't work at all.

One of the popular apps that is integrated with HealthKit, MyFitnessPal, appears to be aware of data loss issues, but it's not clear whether these experiences originate with HealthKit or the apps that are integrated with it.

According to one Hacker News commenter, Arpit Mathur, if there is indeed data loss, it could be permanent. "I talked to an Apple developer at WWDC and was told that HealthKit data never leaves the device (isn't synced with iCloud). Hence the lack of the iPad app. Given that, if the data is lost, it's probably gone forever," he wrote.

Another Hacker News commenter, k-mcgrady, suggested that limitations around testing may have hurt HealthKit:

The problem with HealthKit is the lack of testing. Developers may have had the beta app for months — but it couldn't do anything. The app relies (mostly) on data from third party apps and due to the beta testing limitations (100 devices) people running iOS 8 betas couldn't install HealthKit beta apps and test them with the HealthKit app. Same things applies to keyboards which I've found to be very buggy and I think most of it is on the OS side not the keyboard app side. Hopefully this won't be as big of an issue next year with the new TestFlight service (1000 users limitation).

Bad Timing for Apple

If it turns out that there is a widespread issue with HealthKit, the timing would not be ideal for Apple. The company has seen its fair share of critical press lately because of the high-profile hacking of celebrity iCloud accounts, an iOS 8 bug that caused the loss of cellular service and reports that the newest iPhone bends.

A HealthKit bug that involves data loss, however, could be good news for Google, which is prepping its own Platform for health and fitness apps. The search giant recently released a preview SDK for Google Fit, which is expected to debut with the launch of Android L, the next major version of the company's Android operating system, later this year.

This said, the possibility of a HealthKit data loss bug highlights some of the challenges all players in this nascent space face, Google included. Increasingly sophisticated mobile and connected devices, such as wearables, promise to revolutionize health and fitness, but given the importance of the data they generate for their users, the bar is set very high for vendors, and anything less than perfection will be problematic.

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