"Every step you take... I'll be watching you"

Why you need a wearable device tracking your every move


Jen Hatz MS, RD, CSSD, LDN, CSCS



Trust me, you need that completely devoted, creepy stalker of your wearable device tracking your every move. I fully realized my obsession for being tracked and followed when I recently launched into a full-blown sales pitch at a bar when asked about my smart watch. No it's not an apple watch. It's a Fitbit. And no I don't sell watches or devices, I just love that they know everything about me. They just know me SO. WELL.



"Why would I want my watch tracking everything I do? What is it even tracking besides my steps everyday?"



Your steps mean nothing to me. That sounds harsh, and I know everyone loses their minds over this idea that 10k steps a day is the secret to health and fitness and conquering life. Reality says no way, Jose. 10k steps seemed to magically appear as a gold standard for a daily fitness goal, but really it's just a tangible goal that most people can meet on a daily basis as a part of their lives, whether their days are busy and hectic or completely mundane and sedentary. You're not suddenly less fit today because you didn't hit 10k steps, nor are you suddenly twice as fit because you hit 20k steps. Realistic, tangible, daily goals are the name of the game so if stepping is your thing, that's cool, live it up.


So tracking steps is not the miracle behind these genius little gurus attached to your wrist.


And yes they estimate your calories burned everyday, but this is an estimate based on your height, weight, age, and heart rate throughout the day (a.k.a. your activity level), and these get plugged into an equation to estimate calories. Estimates are not accurate. It's nice to see a number of calories burned for the day to give you a ballpark idea of calories to be eating, but don't mistake this as a reason to "eat back those 500 calories from exercise". Nope. You probably didn't actually burn 500 calories from exercise. And that food you're eating? You're more likely, most definitely, to be over or underestimating how much is actually there. So don't bank on calorie tracking.


"But if you don't really care about tracking steps and calories, then what's the big deal?"


It's the heart rate tracking. And not just looking at your heart rate right now in this moment because if you have fingers, and a wrist, and a pulse, you can check your own pulse right now. It's tracking the trends over time of your resting heart rate and your heart rate variability that I lose my mind over. Those are the big-ticket items that can be out-of-this-world useful. Being able to track those little guys over time.


Why should I care about that?


Well sunshine, your cold dead heart is actually giving us insane real-time feedback about you and your current physiology. [And in the dating world, the absence of feedback does not in fact tell you anything about that person and the current state of their cold dead heart, despite your best friend telling you otherwise. Instead it tells you how they handle, or rather don't handle, facing emotions and difficult conversations, especially where they might have to let someone down.]


Wait, what do you mean by "current" physiology?


Your current physiology, the state that your body (and mind) are currently in tells us EVERYTHING about how you are handling stress. When you have acute stress meaning short-term stress occurring right now (like repping it out to failure in a workout, trying to get around the slow driver in the fast lane, woke up late to your boss calling) your heart rate jumps way up. No shit. You don't need to check your watch to know that your heart rate increases when you experience acute stress. That's normal, and that's not the stress response I'm talking about.


I care about your response to chronic stress. When you have chronic stress, you're resting heart rate is higher than normal, your heart rate variability changes (which we see in your sleep patterns), and your response to acute stress changes (like your heart rate jumps up on your first set or your warm-up, or basically the whole workout feels impossible even though this weight should feel like nothing.)


What's the difference between these?


Resting heart rate: your average heart rate when you are at complete rest, or the average number of heart beats per minute when you are truly at rest. Thrilling stuff, I know. (So your resting HR might be 60bpm, or your heart beats 60 times within one minute)


Heart rate variability (HRV): that interval of time between each heart beat. The time interval between heart beats is NOT always the same. We tend to think a heartbeat is a constant in-sync rhythm with a standard length of time between each beat. False. Your physiology, or the current state you are in, dictates how in-sync or out of sync your heart beat rhythm is. N*Sync however always stays in rhythm.



When you are truly at rest (in a "rest and digest" a.k.a. parasympathetic state) you have a higher HRV, meaning there's more variability between beats, like an off-rhythm funky weird jazz beat that's hard to enjoy because it's not catchy whatsoever, it's just interpretative and creative, so you just sip your drink and pretend you like jazz to impress your hipster friends. So when you're at rest, you're that way-too-chill, off-beat, jazz-loving, possibly barefoot hipster. He's a little off, most likely high, does his own thing, but we like him.


When you are not at rest but instead are getting more amped up, more excited, more stressed, (in a "fight or flight" a.k.a. sympathetic state) that variability between heart beats gets shorter and your heart beats get more in-sync, and more rhythmic as your heart rate steadily increases. This lower HRV (lower or less variability between beats) happens when you're more alert or awake or excited or stressed, like the drum-line rocking away in perfect unison at halftime getting the crowd amped up with their totally synced up hard-hitting rhythm. So when you're getting stressed or excited, it's that synced up rhythm of the drum line pumping you up with their super short, fast reps rolling together in perfect unison.


When it comes to tracking these over time...


Tracking your resting heart rate over time tells us a lot about how you are handling overall stresses placed on your body and mind. If you are over-training, under-recovering, under-fueling, generally stressed, fatigued, etc your resting heart rate elevates and we can see that we need to make a change because your body is telling us with physiological feedback that you are not able to overcome the stressors placed on you.


Adapt and overcome is the goal with any stress placed on you, but if you are NOT overcoming these stressors and getting stronger, more resilient, then you are undertaking these stressors and they are depleting you, weakening your resiliency, and probably distorting your perception of your capacity because you suddenly can't do what used to come easy. It's a no-win situation that perpetuates a negative cycle. Knowing your stress response at the physiological level helps us break that cycle before it sucks you deeper so we can instead push you in the other direction and overcome the stressors. You could say the same for psychological stressors placed on you: your ability to mentally overcome stress strengthens your capacity to handle that stress and you become more resilient, more confident, stronger and more stable at handling challenges. But letting that mental stress eat away at you, and beat you down, depletes you of your ability to overcome it, weakens your resolve and confidence, and probably distorts your perception of it, making it seem like this unconquerable life-ruining storm because you can't get through it.



Tracking you heart rate variability over time specifically gives us insight into your sleeping patterns. Tracking the stages of your sleep cycle goes along with how the different stages present with alertness and brain activity. Refer to the previous post about sleep (What Happens at Night: In the Sheets) but the biggest difference between the different stages is your level of brain (and sensory) activity, which can be tracked through your heart rate variability. [When you are more alert meaning your "light sleep", it'll read as a lower HRV. When you move beyond light sleep into "deep sleep", your HRV increases because you're truly at rest, and when you move into REM sleep, your HRV decreases slightly with more brain activity during dream sequences.]


By wearing this device through the entire night, we can track your sleep with a full breakdown of how long you spend in each stage, the cycles you go through throughout the night, and with direction comparisons from night to night and with your rolling average for the month. This is crucial to understanding the difference between "going to bed for 8 hours because you went to bed at 10pm and woke up at 6am" to actually seeing that you only slept a total of 5 hours throughout the night, most of it was light sleep or just interrupted altogether, and you barely got any deep sleep which is why you actually feel exhausted and drained today despite "going to bed for 8 hours".


Reality hits you in the face sometimes but that's why we love our creepy stalker wearable device tracking our every move. They know everything about us and they aren't afraid to show us what we can't see for ourselves, because they literally observe everything we do. Kind of like the social media algorithms that suddenly spring up ads for things we never spoke about out-loud. They know. You should feel safe knowing that they know more about you than you know about yourself.


Here's something else that females might find interesting...


As a female, we're told to monitor the calendar so we can track or predict our menstrual cycle, and then we're told we're abnormal if we don't menstruate according to that timeline. Well guess what, I already knew I was abnormal Doc, I didn't need you to call me out like that. In fact, a large majority of women are described or diagnosed as abnormal with their cycles because heaven-forbid their body doesn't align with the calendar-tracking method. Well not to discredit the old textbooks, but the human body doesn't know what time it is. Time is a social construct, man. Your body doesn't know what day of the week it is, or how many days or weeks it's been since xyz. Your body responds to stimuli from it's internal and external environments, and your physiology adapts based on the feedback. A female that is chronically under-fueled and over-training, guess what...you don't need to waste precious calories on fertility, you need those calories for survival, so you're not going to menstruate until we know you can actually survive and have enough calories coming in.


But what if I told you this: your resting heart rate over time actually changes in response to your physiology and in this case, your hormonal signaling throughout your cycle. So rather than counting the days on the calendar and praying to the calendar gods, you can actually see a visible pattern throughout the month where your resting heart will increase steadily during the second half of your cycle (from ovulation through the luteal phase, your resting heart rate will increase steadily, until it hits a peak one day and the next day it will drop down. That day after it peaks, when your resting heart rate starts to come back down again, that's the day you will start menstruation.) I've been consistently monitoring this trend and it works like clockwork every time (no pun intended). It's entirely more accurate as a method of tracking and predicting your cycle because it's happening in real-time in response to your current state (which is highly variable and can change if you're stressed, under-fueled, over-worked, etc).



Guys, I can't even make this up...as I'm writing this post, Fitbit literally just launched another feature on their dashboard that SHOWS YOUR STRESS RESPONSE. Literally everything I just explained, they just updated their app so it's right there in front of your face. They quite literally track and follow every move I make and they know me SO. WELL. Bravo Fitbit, bravo.


If that wasn't enough to sell you on it, it has all of the same features and apps as the Apple watch, but it only takes 1 hour to fully charge and that battery charge lasts 4-5 days. You're welcome.