An increasing number of people are quantifying their lives, especially when it comes to fitness. For example, according to my Basis fitness watch, I took 9,192 steps walking around New York City on Wednesday. I burned 2,587 calories and got 6 hours and 41 minutes of sleep between 11:47 p.m. and 6:38 a.m. when I “tossed and turned” 18 times. There isn’t yet a device that automatically tracks how much you eat but — according to the data I entered into my LoseIt app, I consumed about 1,900 calories. So — from a weight-loss perspective — it was a pretty good day. I also know my average and resting heart rate and as well as my heart rate while exercising.
Of course, these values are approximate. Today’s wearable fitness devices are far from perfect but they can distinguish between a couch potato and someone who is reasonable active.
Most wearable devices have accelerometers that try to determine the start and stop of movement based on a variety of factors. In my comparative tests of various watches from Motorola, Sony, Basis and LifeTrak, I’ve found discrepancies, especially compared to walking a known course or actually counting my footsteps, but all were accurate to within about 15 percent, which is close enough if your goal is to simply make sure you’re doing enough walking, running or cycling. Unfortunately, most monitors won’t help with indoor activities — they seem to favor moving from one place to another — but the field is still new and we can expect to see lots of improvements over the next few years.
Heart rate is generally measured optically by lights on the back of the watch that shine into your bloodstream just below the skin’s surface and reflect back changes based on blood flow. They are not as accurate as devices that use a chest strap but they’re a lot more convenient. I bought a Polar heart rate monitor with a chest strap several years ago and, once the novelty wore off, I stopped bothering to put on the strap.
Even if you don’t have a fitness device, you can get some data from your smartphone. Google Fit, a free Android app, does work with many fitness devices and smartwatches but it also measures walking, running and cycling time and distance and estimates calories burned simply by having your phone in your pocket by using the phone’s sensors and GPS to measure time and distance.
What I find interesting about these devices is not just what they tells us about our personal fitness but what they can tell researchers about our collective health.
What we know about health and fitness is based on long-term studies, which, typically involve a subset of the population like the famed Framingham Heart Study, which started following 5,209 men and women between 30 and 62 from Framingham, Mass. in 1948, and now follows their children and grandchildren. Some studies involve people who are being treated for disease — an obviously biased sample or equally biased samples of athletes or college students.
Today, people who wear fitness watches are probably also not representative of people as a whole, with a bias towards fitness buffs. But, over time, such devices could become mainstream. Plus we are likely to see fitness sensors become more ubiquitous. For example, at the CE Week trade show in New York last week, Harry Kalyvas, founder and CEO of Clip&Talk showed off a hands free Bluetooth headset, which, like most headsets, is worn in the ear. So, as long as you have this connected device in your ear, why not let it measure health data. In an interview, Kalyvas said that the device’s optical sensor picks up biometric data including blood pressure, heart rate and temperature, which it sends to an app on your phone. It will be available later summer, according to Kalyvas.
I wouldn’t be surprised to see biometric sensors built-into car steering wheels, bicycle handlebars and maybe even kids’ backpacks along with our shoes and clothing and our beds. There are already products or experiments in each of these categories but they’re far from mainstream. When they do become commonplace, we will collectively be able to gather an enormous amount of data from large and representative samples of regular people as this data is collected and transmitted to centralized servers for analysis.
Yes, there are huge privacy implications about the wholesale collection of this data and there will need to be policies in place not only to make sure this data is anonymous but also to inform people about its collection and use and give them the ability to easily opt-out. But I hope that people will also be given information on the benefit of allowing this type of data to be anonymously studied so that we can gain better insights into what keeps us healthy. For example, we all know that exercise is good for us, but do we really know the trade-offs between effort and reward? We have some ideas but with more data — from tens of millions of subjects — we can gain a lot more insight into how much exercise is “enough” and when we start to reach the point of marginal returns.
So, while paying attention to personal privacy, I say, let the data flow. We can help ourselves and others by measuring ourselves and anonymously sharing the data.