Charge! A Story of Wearables and Human Awareness

This summer at Fuzzy Math, we are exploring the impact and interactions of wearable technology as each member of our team participates in a three-month-long project to explore the ins and outs of these devices. This endeavor will be broken down into three phases: 1) first impressions and getting to know one’s wearable device, 2) empirical evidence and applications for it, and 3) heuristics for each category of devices. This summer-long study is comprised of three separate category groups for the sake of tracking and analyzing data and findings. These groups are activity, awareness, and sleep. For more information, read our introductory post on this project and follow @fuzzymath on twitter, hashtag: #fmwearables.

Category: Awareness

For the FM Wearables project, I’m in the Awareness group. My intent with this project thus far has been to use my Fitbit Charge HR to track my stress levels.

Because there are limited ways to track physical signs of stress (I could only really think of heart rate or breathing), I wanted to find a device that measures heart rate. I’d had a Fitbit Flex in the past and liked its mobile app, so I researched the Fitbit Charge HR, which is an activity tracker with a heart rate monitor built in and — bonus! — it uses the same app.

Curiously, I’ve actually lost most of my interest in tracking my stress levels and gained a heck of a lot of interest in how people (including myself) feel about, think about, and interact with their devices. Hopefully by the end of this introductory blog post, you’ll be able to understand the reasons for this shift.

A Sufficiently Delightful First Impression

User Friendliness

I’ve found both the Charge HR device itself and the mobile app to be pretty user friendly overall. The setup process was also pretty easy; the packaging came with a link to visit to start the setup process. The link lets you download a Fitbit app for your computer, and the app is a wizard that asks you to enter data about yourself so that the app can use it to track your activity. For example, Fitbit uses your height to calculate the distance you travel by multiplying your height (and therefore an estimate of your stride length) by the number of steps you walk to get the total distance. (Yes, I did look this up. More on whether I actually believe the accuracy of this, later!) The computer app and the mobile app both explain how to use the device, how to charge the device, and how to sync the device.


I’m enjoying the design of my Charge HR. I like the plum color, and I don’t think it’s too bright or too chunky. I haven’t had any issues with the wristband so far — I’ve heard reports of some people having an allergic reaction of sorts to a material used in Fitbit wristbands, but I’ve been lucky to not have run into that myself.


I’m actually surprisingly really happy with the battery life on my Fitbit Charge HR. I say this is surprising because I wasn’t convinced I’d have a long battery life after my experience with the Fitbit Flex (the Flex battery only lasted about a day or two, max). In fact, I stopped wearing my Flex because I became sick of charging it so much, and a tiny part of me had wondered how that would be with the Charge HR.

I’m happy to say that I haven’t found charging the Charge HR’s battery to be cumbersome. The battery life lasts about five-to-seven days, which I think is really great.

The charging cable fits right into the device (as opposed to the Flex, with which I had to remove the Fitbit from its wristband to plug it in — not a huge deal, but still a bit of a pain). It takes about a half hour to charge, and then I’m good to go again.

The UI on the device clearly indicates when the battery is starting to run low, and I like that it starts letting me know about this well in advance (even a whole day) before the battery actually dies. I actually haven’t experienced a completely dead Fitbit yet — when the battery is critically low, the UI shows a battery indicator with an exclamation point inside of it which to me means, “I’m dying! Charge me ASAP.” When the battery is just low but not critical, the UI will still run through the stats of my steps, distance, heart rate, etc., but when it’s critically low, it doesn’t display those things.

There have been a few times during a Fitbit Challenge that my battery was critically low because I had left my charger at work, and I was worried Sir Bit would not record my steps. But I was wrong! It still recorded my steps even when the battery was super low. Even though I couldn’t see the steps on the UI of the device, I could still sync it to my phone and see my steps that way via Bluetooth. Pretty nice how gradual this battery cycle process is, without being too invasive.

One last note…
When I finished charging my device and unplug it, a funny/motivating message appears briefly on the screen. It makes me laugh, and so far it’s been a different message every time. It makes charging fun!


The screen on the device itself is small, but the single button simply scrolls through the five-to-six (depending on what the user wants to see) data points that the device collects. I can view the full analysis and my stats’ history on the mobile app. When I double tap the device, it shows me the time (which I can configure to show a different data point if I want to), but I like that it doubles as a watch because I don’t feel the need to check my phone to get the time, which is nice.

When the battery starts to run low, the device screen gives me an indicator well in advance and is clear about when the battery is starting to run low (shows a low battery symbol, and lets me continue to scroll through the data points using the button), versus when the battery is critically low (shows an empty battery indicator with an exclamation point and does not let me scroll through the data points until the device is charged).

The App

The Fitbit app is a dashboard that gives me an overview of the day’s activity and collected data, with the option to drill down deeper into more details for each category. The design is aesthetically pleasing and I can find what I’m looking for fairly easily. The data is pretty complete, but sometimes I can’t view the level of detail I’d like to. For example, I’ve mostly tried drilling down further into the details of my heart rate throughout a particular day. It has a scale of 24 hours, but the only points it shows on the graph are midnight, noon, and 11:59pm during that day. I can’t zoom in on a particular segment of the day if my heart rate is elevated during a particular time, which would be nice for me if I wanted to compare it with the day’s calendar.

One workaround I’ve found is the exercise timer feature. I can press and hold the device’s button to start an exercise timer. During that time, the device is still logging everything I do. However it puts a timeframe around the activity it records – so once I press and hold the button again to tell the device I’m done exercising, I can log the activity type inside the app and view heart rate data for that specific time frame. This is really nice for logging things like biking, which doesn’t register on the device’s step counter. I’ve tried using the exercise logger a few times when I’ve felt stressed — if I notice my heart rate is elevated or I feel really anxious, I’ll start the exercise timer.

An Unexpected Shift in Interest

Skepticism (okay, this was to be expected)

Despite my positive experiences with both the device and the app, I’m not sure how much I believe the data that the Fitbit is spitting back at me (please note I am a skeptical person in general). Here are a few examples of my thoughts about the data:

  • Charge HR tells me I’ve gone up 30 or more flights of stairs, but I’m pretty sure that has never been the case during the days I’ve worn it so far… where does that come from? Was I bouncing around too much?
  • I’m short (5’1”), but I walk faster than most people — even if they’re taller than I am. If Fitbit is calculating my distance travelled by multiplying my stride length with my steps, does that mean the distance that’s recorded by my device might actually be less than the distance I’ve walked? Does every 5’1” person have the same stride length?
  • How does a green light track my heart rate? Is that accurate?
  • Since science hardly knows what sleep is, can I believe Fitbit’s definition of sleep (a lowered heart rate and less moving)? It has been weirdly accurate at measuring the times I’ve gone to bed and woken up, so far…

As a result of my skepticism, I’ve often found myself testing the device. Sometimes I’ll turn on the step display as I’m walking to make sure it’s recording all of my steps (this has been important really only during step challenges with co-workers). I’ll try to track my heart rate by taking my pulse and looking at a timer, and see if it matches up with the device. Sometimes the device is accurate, and sometimes it isn’t. My sleep data always tells me I’ve slept around four or five hours a night, outlining the times I’ve been restless and the times I’ve been sleeping. Can I just not remember these times, and am I sleeping horribly? Or am I sleeping better than my device lets on? These are just a few of my doubts around the data that I’ve become interested in recording not only for myself but for other co-workers who have wearables too.

Existential Crisis

My other difficulties are more philosophical than anything… I’m actually pretty resistant to the idea of wearable technology. My greatest fear is that someday humans will have computer chips installed in them with GPS that tracks their location at all times, or a communication system that requires constant and immediate responses. In other words, I hate the idea of being constantly available and plugged in, despite the fact I feel myself moving more towards this based on how much time I waste daily on my smartphone.

…my wearable is making me aware of things that I’m programmed to not need to be aware of. My brain doesn’t count steps or heart rate consciously, and there’s a reason for that – the information isn’t important enough to be part of day-to-day consciousness.

I can say that the Fitbit doesn’t really fall into either the GPS or the always-available communication category. On the contrary, it has at times actually motivated me to get outside and do more activity, which is something I always love to do and want to do more of.

However, there are increasingly many times when I feel like I should live a simpler life and reduce any distractions that aren’t essential. I would say a wearable, for me personally, falls into the category of being a distraction. It’s another thing I need to think about charging, another app I need to check and sync to, and it’s more data and visualization and analysis to process.

I oscillate between two phases: one where I care a lot about what my daily activity was, and one where I don’t care to see data about how many steps I took during the day or what my heart rate was. Now that I’m thinking about this explicitly, my wearable is making me aware of things that I’m actually programmed not to need to be aware of. My brain doesn’t count steps or heart rate consciously, and there’s a reason for that — that information isn’t important enough to be part of my day-to-day consciousness. Seeing this data tracked is sometimes mildly interesting to me, but it can also be exhausting at times, especially when I’m busy and have a lot of other things to think about. With several entities in the digital and physical world competing for my attention at any given time, the Fitbit data points can feel like extra work and processing to a brain that’s programmed to not register these things.

Shifting Gears

Based on the app’s lack of ability to drill down into a detailed view of the heart rate data, my skeptical outlook, my own personal adversity towards feeling constantly plugged in, and hearing my co-workers talk about their wearables, (not to mention the fact that I haven’t really been feeling that stressed lately), I’ve become less interested in tracking my stress levels and extremely interested in why or why not people believe the data that’s being collected by their devices. During our next phase in July, I’m hoping to re-adjust my foil hat and do some research, interviews, and prying as a part of our heuristics evaluation. Stay tuned!

For more details on day-to-day with my wearable, check out my blog for this project:

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