It’s about 8:30 p.m. on a winter evening, and I intend to spend the next few hours watching reruns of Come Dine With Me while sipping green tea. As I place the kettle on my stovetop and turn the burner up to max, I’m jolted by a succession of vibrations pulsating through my left arm. “Geez,” I mutter, startled, as I look down in annoyance. Like a wide-eyed child pulling at his mother, my Fitbit Surge demands my attention: I took 10,000 steps today. Suddenly, I’m less annoyed. How can I be mad at something that is ultimately a reflection of how well I’m doing as a human?

For the past 30 days, I have been “life-logging” – a type of non-stop personal-data collection that has become associated with what ex-Wired editors Gary Wolf and Kevin Kelly call the “Quantified Self (QS) movement.” The term was coined back in 2007, when Wolf and Kelly recognized that the mass adoption of mobile devices, along with data-storage enhancements and improvements in biometric-sensor tools, was creating the perfect storm for people to start tracking and analyzing their everyday lives. Today, QS has ballooned into an international movement led by Wolf and Kelly, with active Meetup groups in 125 cities across the world.

Some 10 years into the QS movement, there’s an app for just about anything you’d want to track: Apple’s Health (found on iOS 9) is equipped to collect data on everything from your patterns of sexual activity to your body temperature; Start, an app that helps you determine how well your prescription antidepressants are working, encourages you to log your moods; Checky gives you stats on how often you peek at your phone; and Chronos tells you where your hours go (in transit, working overtime, being spontaneous). This year, the latest wearables include smart jewelry, like Bellabeat Leaf, which can be worn either as a necklace or a brooch and tracks stress levels as well as menstrual and ovulation cycles; hearables, which are earbuds that monitor your heart rate; headbands that measure your brainwaves; smart clothing that helps prevent injuries by determining if you’re putting too much pressure on certain body parts; and invisibles, a.k.a. biometric tattoos.

If the QS industry seems health focused it’s because physical activity and processes are the easiest to quantify. The global wearables market is expected to reach a value of $26 billion by 2018, with the Fitbit being hailed as king. But why track at all? What can we really learn from knowing every minute detail of our existence? Even Wolf asked in his 2010 TED Talk (through which many first learned about QS): “What is the Quantified Self for? What should it be for?” While it has primarily been used for product market research and development and biometric 
security (like Apple’s Touch ID system), Wolf argues that the quest for self-knowledge is what’s truly driving this industry.

 Eric Boyd, Toronto-based creator of wearable-electronics company Sensebridge, used to live in San Francisco and attended early QS Meetups run by Wolf and Kelly. 
In 2010, Boyd became one of the founding organizers of Quantified Self Toronto. “[During early QS meetings], we attracted people who were more interested in fun-damental questions about themselves,” he says. “It was people who were tracking 
using spreadsheets or pen and paper. The core of the Quantified Self movement has always been people who are trying to figure out something about their lives and use tracking in order to accomplish that.”

MUST READ: Letter to my 15-year-old self 

“What the Quantified Self does is make what you do more explicit,” says Alan Majer, another co-organizer of the Quantified Self Meetup group in Toronto and the founder of Good Robot, a custom IT firm. “Whether it’s habitual or a pattern, you have a greater awareness overall. It’s really valuable to have that kind of self-awareness because well-being is centered on this belief of self-efficacy – that, actually, what you do makes a difference. QS is those dotted lines – the connection between your behaviours and your outcomes.”

Critics of the QS movement, like Elizabeth Lopatto, a 32-year-old science 
editor for online magazine The Verge, are dubious. “To me, the most troubling aspect of the Quantified Self is that there’s the tendency to judge the numbers as if they’re the most important thing – and they’re not.” The ancient Greek maxim “Know thyself” wasn’t about Socrates counting his steps, she quips. “In terms of self-knowledge, it’s fine to know that you want to walk five miles a day, but that doesn’t strike me as having the same kind of significance as understanding that you have a certain behavioural pattern that you repeat in relationships.”

However, Toronto-based Sacha Chua, a 32-year-old consultant, programmer and blogger, thinks that self-tracking is far from troubling. In fact, for her, it has been downright life changing. During her graduate studies at the University of Toronto, Chua was fastidious about tracking her finances. Frugal by nature, she began carefully tracking her cash expenses and transactions. This gave her the tools to optimize her savings, and at 28 she quit her job as a consultant for IBM and began a five-year journey in semi-retirement.

“It’s possible to enjoy collecting data and asking questions, and you can approach all this with self-kindness,” says Chua, who now tracks everything – from the time she spends on everyday activities and the clothes she wears to old memories and where she leaves different items around the house – on her 
life-logging site, on her blog, and getting to know Chua myself, it seems to me that her on-going “datafication” is driven primarily by the pursuit of a life with purpose – and wonder (an intention QS critics would argue isn’t possible with just numbers alone).

 MUST READ: Can your FitBit tell when you’re heartbroken?

“I’m not trying to wring out every last second of efficiency here,” explains Chua. “I’m just testing: ‘This is pretty good, but I wonder what better would look like. I wonder what little thing would help me understand and appreciate more. How do I play with this in order to explore the possibilities?’ And when you do that, I think you engage with life a little bit more.”

The funny thing is, though Chua engages in what many would consider a rigorous form of data collection, she doesn’t actually own any wearable self-tracking devices. The kinds of questions she’s interested in answering require self-constructed models she builds on her own, starting with hand-drawn index cards. These models eventually become digitized thanks to her programming savvy. For casual adopters like me, on the other hand, wearable technology and apps are the best place to start.

Like Chua, I delved into the QS movement out of sheer curiosity. I wanted my Fitbit to answer questions like: What kind of workouts garner the most intensity? How active am I during the day? Do I eat enough food on weekdays when I’m busy working? And, like many people jumping onto the wearable bandwagon, I had one primary fitness goal: to increase lean muscle mass.

But my Fitbit didn’t understand that I wanted to gain weight, not lose it. After all, the first metric you see when you open the app is “calories burned,” which, in my case, was irrelevant. It’s a technology that seems born out of the eternally dieting woman – the tools associated with weight watching are certainly all there.

MUST READ: Harvard researchers know the secret to happiness

“You can argue that anorexics were, in fact, onto the Quantified Self movement before it existed as they are very rigorous about tracking calories in and out,” says Lopatto. “For people who are in recovery from eating disorders, have active eating disorders or are susceptible to them, these tools let you obsess, and they make your obsessing easier.”

Sociologists have been studying the effects of self-tracking technology on society, and while the overall consensus is that wearables may help to make people healthier, 
issues like extreme calorie counting are only part of the problem. With the extraction of health data en masse, superior health isn’t just measured against oneself; it’s measured against a collective.

Christopher Till, Ph.D., a researcher at Leeds Beckett University in Leeds, England, studies the intersection of health, gender and tech. He argues that wearable self-tracking devices appeal to people in part because they can be ranked against each other. “We’re always being compared,” he says. “To me, that’s one of the fundamental things that these [technologies] do. They kind of objectify your exercise behaviour to something standardized.” With impossible standards of beauty, health and fitness already in place, wearables only seem to amplify this idea that there’s always a bigger, better goal to be reached and that there’s always someone else you need to beat.

“I think women in particular, historically and maybe today as much as ever, are encouraged to compare themselves with other women in terms of their achievements,” says Till. “Men are too, but not, I think, to the extent that women are. This idea of the woman who has it all—who is successful at work and in her home life, looks glamorous all the time, exercises all the time and eats extremely healthily – seems to fit into the narrative that is often presented through these [wearables] of being able to achieve all your goals: the idea that it’s not just about helping you exercise more; it’s about managing this busy life.”

MUST READ: Signed, sealed, delivered

Two weeks into lifelogging, I ran into a friend who also wears a Fitbit; she suggested that we add each other as friends on the app. I can tolerate this type of friend-to-friend information sharing with someone I know, but daily reminders to link my exercise stats with my social accounts always felt off. Though all of my data was housed on the app and only shared among a handful of peers, I still felt uneasy about it. iCloud could already recognize my face and personality via my Facebook, Instagram, Twitter and Snapchat accounts – but now it could potentially have access to the way my body works too?

One of the foremost researchers in the QS movement is Deborah Lupton, a sociologist at the University of Canberra, in Australia. I suggest to her that Millennials, who are naturally inclined to share details about their lives online, don’t seem too apprehensive about giving away biometric data to corporations and “the cloud,” but she believes otherwise.

“Two and a half years ago, we had the Edward Snowden revelations, and since then, we’ve had all sorts of scandals: the Facebook national-mood-manipulation-experiment scandal, the Ashley Madison scandal, the celebrity-nude-photos hacking on iCloud,” says Lupton. “These got a huge amount of media attention. So what my research is showing is that people – regardless of their age – are slowly becoming aware of how their data can be accessed by others. But it’s a gradual process because people are only starting to use [these technologies] and think about their implications.”

“I see stuff on Facebook all the time, like people’s running routes, and I’m like, ‘Oh, my God, don’t share where you’re running at night by yourself!’” cries Jennifer Thomson, a 30-year-old Nike Training Club (NTC) trainer from Toronto, who 
began self-tracking using a Polar heart-rate monitor during her undergraduate studies in physical education. Thomson’s fitness tracking has since evolved (she even uses an app called Bloom to remind her to drink water) as she works toward her first Olympic weightlifting competition.

MUST READ: 9 Healthy eating habits that can change your life

Yet the one thing that all of Thomson’s self-tracking wearables and apps don’t take into account when she doesn’t hit her weight-lifting targets is that she is only human: “That’s where using a spreadsheet comes in handy,” she explains. “I keep a notes column, and it might be something like ‘Only got four hours of sleep,’ so I know why I was having a bad day – that human aspect always has to be there.”

As part of Lupton’s research on self-tracking, she asks subjects “What can’t the device tell you?” “And one man said, ‘You know, it can’t tell me whether I had a fight with my wife or whether I’m just in a bad mood,’” recalls Lupton. “We wouldn’t want to reach a point where the only knowledge about ourselves that we consider valuable is the kind of knowledge we get from digital data because it’s incredibly reductive. It leaves out a lot of elements of our lives that can’t be measured by digital devices.”

When I look back at my 30 days of lifelogging, I’m somewhat surprised to realize that the regular buzz from my Fitbit Surge – telling me, say, that I’d hit my step goal or that I’d gained a few pounds – wasn’t as satisfying as I thought it would be. To be honest, it started to feel more like a shackle than a knowledgeable best friend, slowly turning into a warden of my day-to-day life (the nagging coach when I was exercising or the giver of useless biometric stats when I was bored at work).

Instead, what truly gave me joy was remembering how many times 
I laughed, how many words were spoken or how many times I ran into someone I knew. I’m aware that these tidbits of my life can be turned into chunks of data to be analyzed and optimized, but I’d rather they not be. My self-knowledge tells me that these things make me better, whether they’re quantified or not.

ELLE First: The one that got away
Financial coupling

We decode your best summer-workout plan