Eloise Le Santo has a sixth sense. She can feel her body’s patterns: her oscillating levels of weakness and strength; her mental sharpness turning dull and then sharp again; and her emotions — the way that anger predictably subsides into calm. From noticing these sensations alone, she can tell when she’s ovulating.
Le Santo developed this sixth sense after she started tracking her menstrual cycle using Glow, an ovulation and fertility calendar app. The tracking made her more attuned to how her body changes throughout the month. She started noticing subtle feelings that have eluded her previously.
Le Santo is part of an emerging group that uses apps and wearables as “prosthetics for feeling,” or artificial extensions that give them new powers. The term was coined by Linda Stone, a writer for Radar. For the most part, a wearable is a bracelet or watch that counts the hours you sleep and the number of steps you take, and then scolds you if the numbers are too low. Stone characterized this as an alienating way to relate to your body. Instead, technology could facilitate better health by supporting you. Ideally, health tech would help users gain mindfulness and wellbeing, rather than bully them into achieving specific targets.
If you use a wearable long enough, you may not need one anymore. Some forms of health data tracking can increase users’ bodily awareness, according to the 2016 book Self-tracking, written by University of Washington data scientist Gina Neff and Intel research scientist Dawn Nafus. “The data becomes a ‘prosthetic of feeling’, something to help us sense our bodies,” they write. Eventually, like training wheels, the technology may be discarded altogether.
At the 2012 Quantified Self conference — an event that brings together people who are dedicated to using tech to optimize their health — one woman reported that, like Le Santo, she had learned to tell if she was ovulating without any tools, after having tracked her cycle as a patient at a fertility clinic. At one point, she knew she was ovulating but the test at the fertility clinic indicated that she wasn’t. She insisted the clinicians run another test, and when they used a more accurate measure they found that she was, indeed, ovulating. The ovulation tracker was a “prosthetic for feeling” in that it had helped her tune into the cycles of her body to the point that she had a better idea of when she was ovulating than an instrument designed specifically to tell.
“With practice, clients start to know their heart rate fairly accurately just by feel.”
Bob Troia doesn’t have diabetes, but has been involved in a long-term self-experiment in tracking his blood glucose levels over time (which you can read about on Troia’s blog, Quantified Bob). Until recently, he wore a continuous glucose meter about the size of a quarter which took measurements every five minutes. As a result, he started noticing sensations that he’d never paid attention to before. He learned to interpret them and could deduce his glucose level without looking at his monitor. For instance, during fasts, he says, “I might start to notice some tingling or cold sensation in my hands, which is a sign of low blood sugar.” Other diabetics have reported the same thing about “glucose awareness.”
This level of awareness can also be linked to greater body control. Harvard research from 2009 showed that people who recorded their heart rate for a minute at a time, multiple times a day, could learn to deliberately slow it down. This could help them regulate their emotions better and they may be able to apply the same skills to regulate uncomfortable symptoms like migraines or poor circulation.
I spoke to Virginia-based personal trainer, Chris Clough, who has noticed that clients who monitor their heart rate during interval training eventually learn to detect when they’ve appropriately rested from a high intensity phase and are ready to pick up their activity again. “Knowing when the heart rate is ready to go again is important,” he says. “A shortened period of time to a lower heart rate target is a good indicator of improved cardiovascular conditioning. With practice, clients start to know their heart rate fairly accurately just by feel.”
More than 44 million Americans are predicted to own a form of wearable technology this year, according to eMarketer data. Whether all of them will be able to use their wearable as a “prosthesis for feeling” seems unlikely, at least partly because people aren’t generally interested in using them long term. One survey of thousands of Americans found that after 18 months, half of all people who purchased a wearable were no longer using it. The most significant drop-off rate happens in the first six months.
I wanted to see if I could learn to control my heart rate, so I followed the Harvard study. Every three hours for two weeks I recorded my heart rate using a wearable. Although the research suggested that people could change their own heart rate after a week of recording it, I was not able to. If anything, my heart rate went up when I watched it, possibly because trying to control a function of my autonomic nervous system made me feel flustered.
It’s also possible that my gadget isn’t accurate enough to tune my sensations to the number on the screen. Last year, a class-action lawsuit was filed against Fitbit because of the alleged inaccuracy of its heart rate monitoring function. Indeed, aside from his glucose monitor, Bob Troia told me that he simultaneously uses three wearables that measure essentially the same thing — a Fitbit Blaze, a Jawbone UP3, and a Ōura ring — because they give wildly different results on basic measurements like the number of hours he’s slept.
Despite these shortcomings, he’s pretty positive about what self-tracking offers. “There is so much insight that can be obtained about oneself using an inexpensive glucose monitor that can be purchased for under $30 in less than 60 seconds,” he said. “I don’t understand why these aren’t offered to everyone for free… For me, what started out as a monitoring/preventative measure turned into a self-discovery tool that is allowing me to better understand my body.”