Skip to main content

How was the workout? Let me ask my smart socks.

My wearable fitness trackers collected plenty of data. But there’s something they were missing.

By Matt Crossman

“With all that sweat, you look spectacular.”

I blushed at the compliment as I jogged through my neighborhood on a too-warm summer morning. I would have been flattered — and bragged about it to my wife, friends, brothers, neighbors, and strangers at the grocery store — if the come-on hadn’t come from my socks.

Designed to help joggers track their runs and improve their form, these socks have sensors on the soles, which connect to microelectronics on the ankles, which connect via Bluetooth to an app on my phone.

They also come programmed to appeal to my vanity. In a voice that sounds like a sassy female robot — crisp, abrupt, a hint of an accent she’s trying to hide — she made it clear that she knows what she wants (me, apparently) and isn’t afraid to go get it.

Or maybe (fans self) I’m reading into it.

Anyway, when they weren’t wolf-whistling at me, the socks, made by a Redmond, Washington-based company called Sensoria, told me how fast (or not) I was running, how smooth (or not) my strides were, and which parts of my feet were hitting the ground first (heels). Sassy Female Robot offered cheesy inspirational bromides, a question about whether I’m running that fast because zombies were chasing me, and the aforementioned come-hither comment.

Whether I looked spectacular or nasty, I felt good at the end of that run, and that was the point. The socks were part of an attempt to hack my health using wearable devices, capitalizing on a wave of new consumer products that promise to change your life by helping you optimize everything: your sleep, your speed, your readiness.

Self-motivated and passionate about fitness, I live smack in these products’ wheelhouse. I already owned a Fitbit 4 watch, which I use to track my heart rate, workouts and distance traveled. To that I added the Sensoria socks ($398), a shirt that measures heart and lung function from a company called Hexoskin ($497), and a sleep-tracking ring called Oura, which the NBA and NASCAR used to detect COVID-19 symptoms during the early days of the pandemic ($399). All of them talked to me via apps on my phone, though only the socks spoke out loud.

For two months, I wore the ring and the watch nearly all day, every day, and the socks and shirts during workouts. That gave me an overwhelming amount of data about myself — every heartbeat, every step, and much, much more.

There’s a global community of people who gather data on themselves, much like I did. It goes by the name of Quantified Self, and its members conduct data-collection projects they call “personal science.” The subjects range from relatively simple (tracking hearing loss) to illicit (the effects of hallucinogenic drugs) to profound (two people separately charting whether they did what they said they’d do).

Thomas Blomseth Christiansen, a technology entrepreneur from Denmark, collected data on all his sneezes for five years and shared the results at a Quantified Self conference. He sneezed 1,019 times in 2012, 533 in 2013, 486 in 2014.

Steven Jonas, managing editor of Quantified Self, says the point of any self-tracking project is not just to collect and collate data. The key is to find a takeaway for self-improvement. Sometimes that means discovering a medical issue or developing a plan for self-care. Christiansen learned that his sneezes came in clusters and were far worse in his native Denmark than elsewhere. By analyzing that information, along with other data about food, he learned to control his allergies. Now he no longer needs to take medication for them.

Could my wearable devices help me make a similar discovery? The products’ marketers sure make it sound that way. Stephen Intille, a professor of computer science and health science at Northeastern University, has studied interfaces that aim to help people get and stay healthy. “The devices, in the long run, have potential,” he says — to zoom in on problems, identify solutions, and change lives for the better.

That all happened to me, for a while. But something else happened, too. Before I was even aware I was doing it, I started to let the devices take over. In relying on them, I started to behave as if I was one — as if, were I just to oil this gear, I would operate better. The data overrode my own decision-making. I started to trust it more than I trusted myself.

I began my data collection project with the Oura, the sleep-tracking ring. I have wrestled occasionally with poor sleep, never worse than this past summer. Sometimes I can’t fall asleep; sometimes I can’t stay asleep; sometimes I wake up unrested. I hoped the ring would help me understand what was happening and help me fix it.

Sleep experts say the biggest key to sleeping well is to be consistent — go to bed at the same time and wake up at the same time, even when you don’t have to. After a few weeks, the Oura discerned when I slept best and set my bedtime accordingly — usually 9:15 to 10:15 p.m. It reminded me via push notification. I haven’t been told when to go to bed in four decades, and even then, I stayed up late reading the Hardy Boys. But I diligently obeyed the ring.

As I realized the power that I had given the ring, I turned defiant.

The ring said the ideal bedroom is dark. I installed blackout curtains. The ring said the ideal sleeping temperature is 65; my wife would’ve had to wear a parka if I’d turned it down that low, but we compromised and turned the overnight temperature from 77 to 72. To please the ring, I gave up afternoon coffee, ate dinner earlier, cut blue light in the evening, tried to relax before bed, and as often as I could, climbed into bed at the appointed time.

And, just as Christiansen’s study helped him stop his allergy flare-ups, the ring helped me sleep. The improvement was immediate. Before I made any changes, I slept 6 hours, 20 minutes per night. Once I started obeying the ring, I jumped to 7 hours, 17 minutes.

The ring was astute at guessing where I’d gone wrong. One morning early on, my ring said my heart rate had taken a long time to slow down the night before, a metric of less-than-stellar sleep. “Could it be that you ate too close to bedtime?” the ring wondered.

I had.

I was hooked.

The most challenging piece of advice the Oura offered was its “readiness score.” I wore the Oura on my right-hand middle finger. As I slept, the ring shot infrared light into my finger to track my heart rate, heart rate variability and body temperature. The app provided a report detailing those numbers, plus how long I spent in each sleep cycle (deep, light, REM) and how much I tossed and turned. It used those measurements to calculate whether I had recovered enough from the previous day’s stress.

The number runs on a 0-100 scale; I guess zero would mean you’re dead and 100 would mean you’re Superman on uppers. My highest score was 91. My lowest was 66.

“Bring it on!” the ring said one morning, announcing an “optimal” readiness score.

“Your resting heart rate indicates that you’ve recovered well. Do you feel energetic?”



I think.


Do I?

It started slowly and so subtly, I didn’t realize it was happening: I didn’t know if I had slept well until I checked my sleep score. I didn’t know if I should work out that day until I checked my readiness score. I lost confidence in my own self-awareness. It was like relying on the phone for directions to go somewhere I visit every day.

As I realized the power that I had given the ring, I turned defiant. On July Fourth I stayed up late watching fireworks, slept poorly, and woke up to a low readiness score. “Take it easy today,” my ring told me.

Forget that, I feel fine, you’re not the boss of me, I retorted … not out loud — I wasn’t talking to it out loud, yet. I went outside in high heat and humidity, did strenuous yard work for an hour, and felt like I got run over by a truck with spiked tires that reversed and backed over me again.

The ring was right.

I should have taken it easy.

Did the ring know me better than I knew myself?

The evidence suggested so.

I returned to being obsequious after that.

For a while.

The first time I tried to put the Hexoshirt on, I stopped because I thought they’d sent me a shirt two sizes too small. I finally jammed myself into it; it squeezed me like an overeager python. That tightness is a requirement. Three sensors sat snug against my chest and torso and recorded heart rate, breaths per minute, and liters of air gulped per minute.

Watching in real time what your body is doing is enthralling. Every time I showed up at my outdoor workout group, my buddies crowded around me, staring at my shirt and the connected app on my phone. Touch this button and it’s a handheld ECG machine. Touch the button next to it, and my lung activity rose and fell like waves. “Watch this,” I would say, before I took a deep breath and watched the wave grow bigger. I had already turned sleep into an equation to be mastered. Now, I turned my heart rate into low scores and high scores and tried to break them.

Friends joked I was becoming the Bionic Man. I was a living algorithm, even if I didn’t always know what to do with the information. Every morning, I pored over my deep sleep, light sleep, and REM numbers. When my socks said I ran lopsided and indelicately — both feet hitting the ground too hard, my left foot especially — I tried to run more smoothly.

But these were mere frivolities compared to my obsession with the Oura ring’s readiness score. In search of ever-better readiness numbers, I rode a wave of early to bed, late(ish) to rise. My sleep improved, my readiness improved, and I felt better. I was ready to take on the world … as long as my ring said I was ready.

And then … and then … nothing else happened.

I plateaued, and then I lost my sleep gains.

Worse than that, I started to wonder what I was missing. I feared being ill-prepared when I had a less-than-pristine readiness score, so I skipped rigorous workouts with my friends. By behaving in accordance with the readiness score, I was proving it right. My text chain with my friends lit up with laughter over shared suffering that I missed out on. Jealousy crept in. My confidence crumbled.

I started to doubt the value I conferred upon the readiness score. I took a closer look at exactly what the ring told me and found it wanting. “Looks like something affected your sleep quality last night,” it said one morning.

No shit, Dick Tracy. But you didn’t tell me what that “something” was.

“Can you make sleep a priority tonight?” it asked after I slept terribly again, as if paying $399 for a ring, wearing it 24/7, and following its every suggestion wasn’t enough proof I had already made sleep a priority.

“It looks like you’ve had enough easy days in your workout routine lately,” it nagged one morning and … I just … SCREW YOU. MY SOCKS THINK I’M HOT.

I tossed and turned but received a high sleep score from the Oura. Or I felt like I slept great, but the score didn’t reflect it. The honeymoon had ended, because I no longer trusted the numbers.

Dan Ledger, a wearables industry technologist and consultant, co-wrote a white paper in 2017 that showed roughly a third of customers stop using their wearable devices after six months. The reason: they think they’re getting unreliable information or bad advice. When I spoke to him recently, his analysis hadn’t changed: I had butted up against wearables’ dirty secret.

“[If you think,] ‘This description doesn’t seem right,’ or ‘This advice seems bad,’ you’ll probably never wear the product again,” he said.

Jonas, of Quantified Self, agrees that wearables have limits. “I think some people want to get to a place where the tools are so smart, it tells them what to do, they comply, and they feel better,” he told me. “And maybe that will happen, but I feel like they’ll still fail because you still have to motivate yourself.”

Ah, motivation.

The elusive why — the missing piece in all of this.

Why do I do the things I do?

I’m not sure I know half the time. And I’m damn sure the ring, watch, and socks never know. The devices lack a rich understanding of human behavior and individual situations. Something was messing with my sleep and readiness scores that my wearables didn’t know and couldn’t have understood if they did.

I almost didn’t tell this part. My mom died last December. She didn’t want a funeral, she wanted a party, so we threw her one. COVID-19 delayed it until July. In the middle of my wearables experiment, I drove from Missouri to Michigan to give her eulogy at the party in the retirement community where she and my dad lived. It was one of the toughest challenges of my life. There’s not a readiness score in the world that would prove me ready for it.

I have a mantra when I get exhausted during endurance events: One more step. I can take one more step. I rewrote it for the eulogy: One more sentence. I can say one more sentence.

More than 100 people gathered in the community clubhouse to drink margaritas and eat tacos in my mom’s honor. Her love for margaritas was unknown to me. The fact she lived a life worthy of 100-plus people gathering at her party, seven months after she died in the middle of a pandemic surge, was not.

I was proud of what I wrote, but not how I delivered it. I fumbled, lost my spot, forgot parts. I didn’t blow it, but I didn’t do well. The anxiety showed up in my data. Early that week, my resting heart rate was 59. It was 61 the day of the eulogy, 118 during it, 63 the day after it.

But I knew within hours of the eulogy that whatever stress it put on my body was worth it. I got to stand up in front of more than 100 people and talk about how awesome I thought my mom was and how much I loved her. Even better, dozens of people told me afterward how awesome they thought she was and how much they loved her.

I had forgotten about the rewards of doing hard things.

The memorial party reminded me.

Only after weeks of reflection did I see what this meant for my attempt to hack my health with wearables. Faced with hard physical challenges, I hid from them and blamed my trepidation on my readiness score. I started to believe that the score was right, that I wasn’t prepared for hard things. I interpreted the ring’s advice as, If you’re not ready, don’t try. That’s a terrible way to think.

Of course, I wasn’t ready for the eulogy — that’s entirely the point of doing hard things. If you know you’re ready, they’re not hard. The most important improvements I’ve made in my life came from knowing something would be difficult, doubting whether I was ready, and doing it anyway. If I’d waited until I knew I was ready to get married, become a father, take that new job … I’d never have done any of it.

At first, I thought this conclusion revealed that my entire project was a failure. I set out to improve my readiness and decided I didn’t care about being ready. Jonas saw the opposite. He saw it as a worthwhile discovery. He told me I had rediscovered what I considered important about the value of doing hard things. Giving the eulogy and getting a shower of love upon me afterward were the first steps in regaining the confidence to challenge myself.

The ring missed how important that confidence is to me. No device can understand it. They compare you to general goals and general benchmarks. But they don’t really know you. Not yet.

“The technology has the potential to allow for a lot of tailoring,” Intille told me. “The devices don’t really have enough information yet to be able to do that. That’s the future. That’s what we’re trying to figure out how to do.”

It will be a formidable technological challenge. The areas in which we want to improve — happiness, depression, and anger — are hard to measure. For example, the “tells” that a body gives off when it’s stressed — changes in respiration, heart rate variability, body temperature — are sometimes indistinguishable from laughter.

Ledger, the co-author of the white paper about wearables, says any big leaps in the industry likely will require reimagining how the devices work. Instead of relying solely on measurable data, the devices will need input from the user. Maybe if I tell my ring I’m happy or depressed or angry, the ring will be able to figure out markers that foretell that state, much like it saw COVID-19 coming in the NBA and NASCAR.

Another change could come through the prompts that devices offer. Once, I got annoyed at my Oura because it knew I had been sitting for too long, so it told me to get off my butt and move … only it didn’t know that I couldn’t, because I was in the middle of an eight-hour drive to give the eulogy.

Intille says devices could learn better timing, and which prompts work and which don’t, and target their responses to their users. “Perhaps a message framed one way rarely seems to lead to a behavior change for you,” he says, “but a message framed differently does. Devices may adapt to you by monitoring and responding to what you typically do.”

The socks hit on me three times. What if they figured out that the flirting made me faster? They could bat their eyes in the final quarter mile of a race if I’m close to a personal record.

The industry hasn’t gotten to that kind of user targeting yet. Until it does, I’m going to leave my Oura ring in the dresser, where I put it months ago.

I’ll decide for myself when I’m ready to use it again.

Published on

Matt Crossman is a writer based in St. Louis. He has written for Sporting News, Sports Illustrated, The Athletic, Men's Health, and The Washington Post.


Animation by Chloe Prock. 

First Person

Ming Tsai wants your vegetables to taste awesome

The chef and TV host on inspiration, food innovation, and the joy of Chinese braises

By Schuyler Velasco