I, like many others, was bitten by the bizarre HealthKit bug that causes the Health app to lose data. Coming on the heels of iOS 8 renewing my interest in self-tracking this frustrated me to no end. I have a reasonable theory as to what caused the app to die and lose data—too many apps were trying to feed data into HealthKit. Like I suspect many other enthusiastic self-tracking iOS 8 users, I dumped a metric ton of HealthKit enabled apps onto my Phone as soon as 8.0.2 came out. In my case, this included: MyFitnessPal, Jawbone UP, Centered, MotionX 24/7, and FitStar. This was too many at once, and I wouldn’t be surprised if some of those apps had bugs in how they communicated with HealthKit at launch.

To start, I uninstalled every single app that used HealthKit, and along with them, removed all the data they stored in the database. I then went back in and deleted every last piece of data that had been added in Health—either by hand, or by apps I ditched. This was a bit more tedious than I expected… until I noticed the “Clear All” button in the top left corner. In the end, I had a clean slate to experiment with, so I could identify when and where things failed. I reintroduced apps one at a time: MyFitnessPal was the first, and I built my Health App ecosystem up around it, trying to avoid redundant apps that would conflict when writing and reading data. Among these, was replacing MotionX 24/7 with the updated version of Sleep Cycle, to avoid another app that collected and wrote steps data. I knew it was working when my sleep data finally started to appear in Jawbone UP again.

After running with this streamlined setup for three days, it seemed to work well, except for a connection issue between Jawbone and MyFitnessPal for food tracking. Unfortunately, when I went to write this piece, I found Health had choked and died again. That’s when I found Apple’s Knowledge Base article on Health data not updating. After following those steps, including the awful forcible rebooting of my iPhone, my app came back, minus a few steps and the 100 calorie bag of cheese popcorn I ate at my desk. The iOS 8.1 update arrived as I wrote the above, with a potential fix included. In the afternoon and evening since updating, it’s been… intermittent. I did try the force reboot solution a few times before and after the upgrade. A day later, it looks like most data is synchronizing correctly, except the step counting, which is the most frustrating.

I’m disappointed, to say the least, that such a flagship feature of iOS has been so flawed. For an app with such potential to change people’s lives, and serve as a centralized back end for the growing ecosystem of health data collection, Health feels like a step backward. The broken step counter on my phone is mind-blowing, since the Pedometer++ app, which pulls data straight from the M7 without using HealthKit, is still keeping an accurate count. None of this makes any sense to me.