ReadWriteBody is an ongoing series where ReadWrite covers networked fitness and the quantified self.

When Apple first unveiled HealthKit, its software for weaving together fitness apps, wearables, and iPhones, there were more breathless exclamations than you’d find in your average SoulCycle workout.

I was quick to deflate the hype around HealthKit, pointing out that the skimpy specs and documentation Apple released this summer showed that it was geared around fairly specific medical tasks, like recording a body-temperature reading from your armpit—not the needs of fitness-app makers.

Since then, Apple executives have been busy taking meetings with fitness-focused developers, and the most recent beta release of iOS 8, the next version of its iPhone software, suggests that HealthKit could actually be a helpful workout buddy.

Crucially, Apple introduced new data types and functions in HealthKit for logging workouts earlier this month that didn’t exist in its first release. HealthKit apps can now log workout type, duration, and calories burned.

Even medically-oriented apps can capture more meaningful data now. Samir Damani, a cardiologist and CEO of MD Revolution, a fitness-app maker, pointed out to me that the first version of HealthKit didn’t capture data like a user’s body-fat percentage, which clinical studies have shown is a better predictor of fitness than weight or body-mass index. In its latest update, HealthKit now includes body-fat statistics as a metric.

In this regard, Apple is playing catch-up with Google, whose Google Fit software tools launched with far more developed workout-related features, and a better structure for adding new data types based on Android.

The latest reports suggest that Apple will announce a wearable device, the so-called “iWatch,” in September—earlier than previously expected. The only clue to its function in Apple’s documentation is HealthKit’s ability to record heart-rate data from a wrist-based device.

HealthKit also records sleep-quality information, distinguishing whether you’re in bed or actually asleep—data that devices like the Jawbone Up, Fitbit, and Runtastic Orbit can collect.

The question, though, is what Apple will do with all this data, whether it comes off an iWatch or other wearables that interact with HealthKit.

“It’s not in Apple’s DNA to interpret data,” says MD Revolution’s Damani. That will be up to HealthKit-ready apps.

It’s a healthy sign, though, that Apple is making such rapid progress in fleshing out HealthKit, and going beyond just vital signs that a nurse might collect in a doctor’s office to the real signals of a healthy body that we produce when we work out.

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