Data management is hard (WHOOP!)

I'm a big fan of WHOOP but I noticed that it has a data management problem when it syncs my high-resolution heartbeat data to Apple Health. I reported this to Whoop customer support and they said it wasn't a bug, but the app working as designed. If true, that's a significant problem that shows a lack of attention to data management.

Here's the issue: my Whoop records every heartbeat (and a lot of other data). By looking at this high-resolution data, it can determine a lot of amazing things — for example, how fast I'm breathing when I'm asleep. It can even infer my blood pressure, although the FDA is angry at Whoop for making that information available to me without becoming an FDA-certified blood pressure meter. Whoop stores all of this information in body-worn device and syncs it to the Whoop cloud through an app on my cell phone.

It's also possible to have Whoop push data to Apple Health so that it can be shared with other applications. I've been doing that for several years.

Earlier this month, my 128GB iPhone reported that it was short on storage. So I went searching and discovered discovered that Whoop is storing my high-resolution heartbeat data in the Apple Health database. It is the only app that I have that is storing such high resolution data. The numbers (see below) are staggering - Whoop is storing 1.22GB of data in my Apple Health. The next nearest app is my step counter, which stores 28.6MB. Something is clearly wrong.

Whoop should be doing data minimization. After all, Whoop keeps high resolution heartbeat data in its own database; it doesn't need to push this to Apple Health, which lacks tools for managing data of this size.

I think that this is an oversight on the part of Whoop's designers. This is not the sort of thing that shows up in testing - it only shows up after years of use, and then, only people who are running short on phone storage and start investigating why, like me.

I reported this to Whoop and the tech support just bragged about their high-quality heartbeat data and said that the app is acting as designed. Yes, Whoop is designed to collect and use such high-resolution data. But no, this data does not need to be pushed to Apple Health. And once it's there, there's really no good way to delete it because, it seems Apple never suspected that an app would send through so much health data.

(Whoop tech support insisted if I stopped data sync that the data would be deleted, but that didn't happen. And while I can delete all of my Apple Health data, I can't delete the heartbeat data.)

This is the only bad experience I've had with Whoop so far, but I'm concerned that it may be a sign of growing pains. Data management is hard.

So what are the lessons here?

• Even if your app does amazing new things, make sure that its data storage is consistent with the locations where you plan to store data. In this case, Whoop should store different amounts of data in its own data store and in Apple's.
• Model how data storage will grow over time.
• Be sensitive when users call up about data storage issues. They might not be significant concerns for you, but if they are calling up, it's a bit deal for them.