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Due in part to the rising epidemic of obesity in the western world, devices that claim to track health through physical activity have found their niche. These devices are designed to track your resting heart rate, number of steps taken per day (much like a pedometer), calories consumed over the course of the day, and even your quality of sleep. While these devices can be used to great effect in measuring the effects of your lifestyle and the improvements being made to it, they’re not a good way to perform a health assessment, or to measure your overall personal health. In essence, they function as little better than a glorified pedometer with some additional functions.
What do Activity Trackers Do? 
An activity tracker merely measures lifestyle related metrics and relays them to a piece of computer software, often syncing the device with your mobile phone. This allows you to track these health related metrics with more ease than ever before, but they are not an effective way to perform a health assessment, nor are they a good indication of your overall condition.
Activity trackers do measure some key metrics that can be fundamental to improving your overall health, but they are not measurements of health in and of themselves. Health tracking and having information on your physical activity and sleep levels isn’t of much use to you if a disease process has already set in. Even the most physically active person can occasionally be blindsided by heart disease, cancer, or metabolic illnesses due to the western diet and lifestyle. The rates of these diseases has risen to epidemic levels because of the combination of a sedentary, stressful lifestyle and little to no education on the basics of nutrition. And the consequences of these poor lifestyle choices often won’t show up on anything but a laboratory test until it’s too late to reverse the damage. An activity tracker can be a useful tool in tracking efforts to reverse the damage of certain lifestyle choices, but they aren’t a replacement for a physical exam performed by your family doctor.
Are Activity Trackers Actually Accurate?
Some wearable devices may not be accurate in measuring your activity or sleep levels to begin with. This applies especially to devices that sync with a mobile phone and utilize an accelerometer and altimeter. What this means is that they rely on both GPS tracking information and the subtle movements picked up by the device’s internal sensors in order to measure the distance moved and the amount of steps walked. But a lot of things can cause these two internal trackers to register inaccurate measurements.
Basic household tasks such as bending down and standing up while doing laundry can be enough of a trigger for the accelerometer to register a step, even when you haven’t actually moved. The device can also be tripped up by a car, which can confuse the GPS tracking data, and even walking up and down the stairs in your home can register incorrectly. When analyzing the data that these devices provide at the end of the day, one absolutely must take these confounding factors into account. These small discrepancies add up, and may even cause your daily amount of calories “burned” to be inaccurate. Unless you’re extremely vigilant about your caloric intake and carefully track your physical activity, your reliance on activity trackers may lead to less weight loss than you were hoping for.
Measuring Your Sleep
Even when measuring sleep quality as part of your health assessment, these devices can still make mistakes. It’s not uncommon for people to move during some of the lighter non-REM sleep stages, even if this movement is slight. A device that relies solely on movement in order to measure wakefulness isn’t always programmed to take this nuance into account. Furthermore, subtle changes in body temperature and heart rate can be enough to trip an activity monitor’s sensors, even when these changes on their own are not indicative of wakefulness. An activity tracker also doesn’t accurately measure brain waves during sleep, our best indicator of wakefulness. Some conditions, like sleep apnea, may cause temporary wakefulness that can only be measured by taking into account both the electrical activity in the brain and your respiratory rate. But your average activity monitor simply isn’t capable of this.
For the average person looking to assess their sleep quality as part of their health tracking efforts, an activity monitor may be able to give you a basic idea. However, for anyone with even a suspected sleeping disorder, these devices are worse than useless. The only means of accurately measuring the true quality of one’s sleep or trying to diagnose a sleeping disorder is to participate in a sleep study under medical supervision.
How to Use an Activity Tracker
That is not to say that these devices are entirely useless. It bears repeating that if you want to make a serious change to your life style, an activity tracker can provide not only useful baseline data but also quantify the degree and quality of the changes being made. You just need to make sure that you don’t use them as an indication of overall personal health and well-being. For that, you will want to pay a visit to your family physician.
Activity trackers have their place within the realm of fitness routines. As stated previously, they’re a fantastic way to quantify the results of your lifestyle changes. For example, they far more accurately record the number of repetitions you perform during high intensity strength training exercises. This can give you a clear idea of how much work you’re actually doing, and how you’re progressing. Increases or declines in the number of repetitions that you’re capable of performing on each day can also be analyzed for compounding factors –such as diet, sleep, and workout frequency, in order to optimize the routine for maximum benefit.
Tags: health tracking, health assessment, personal health
