The Value of Online Trackers Part III, Exercise

So what does a fitness tracker measure in regards to activity and exercise?



11/24/20213 min read

Fitness trackers vary a little bit in what they can and cannot do, according to price point. For the bigger name brands, the trackers that are under $100 basically only measure steps, the ones above $150 measure more than that.

So let's delve in.

The pedometer feature has come a long way in regards to accuracy, but it still isn't 100% perfect.

Pedometers work like a motion sensor to detect a certain pendulum movement back and forth of your wrist when you walk or run.

Which in today's society is very limiting! What about the other activities? What if you play on your phone while working out? (Btw, I am on the treadmill typing this.) What if you are carrying stuff, or pushing a shopping cart, or holding hands? YES, the wearable will miss steps, absolutely.

I have a magnetic band that allows me to put it on my ankle. Cost me $6. Problem solved.

And yes, I did test it over a few workouts. Ankle wearing only had about 150 more steps than wrist wearing for basic walking outside and on a treadmill. So every day, it gets switched for my workout.

Moving on to other features, the next most important feature is the heart rate monitor. This solves a few more tracking issues and gives you more insight as to how hard you work.

Heart rate monitors used to involve a chest strap, but now it's a little flashing LED light on the underside of the tracker. It has been stated by multiple sources that constant exposure to the light is not harmful. After wearing one for several years, I haven't seen any ill effects on my skin.

The heart rate monitor measures resting heart rate, which is a great number to measure how "in shape" you are in regards to cardio activity and perhaps even cardio health. So the lower your number, the healthier your heart may be, in regards to recovery from exercise. There's much more to it than that, but that's a good place to start.

So basically as you incorporate more frequent and more rigorous exercise, you'll obviously see the higher number during, but over the days and weeks going on like this, the number while you're at rest should drop. If not, it might be your diet, stress levels, or something else going on.

Cardiologists have been known to use these numbers when helping their patients for extra insight.

So then when you are exercising, the amount that the number goes up helps the device calculate calorie burn.

For example, I walked for an hour on Sunday, outside in boots. I burned 481 calories, which is much higher than the normal 355 that I might burn in the same amount of time. Big difference! But I was working harder, and the evidence was in the heart rate tracking. I spent 57% in a cardio zone and usually on the treadmill, unless I push it, over 90% of my time is in the fat-burning zone.

These zones are ranges of heart rate beats per minute that are considered low, medium and high impact. Again, there's way more to it, but at least that's a definition to start with.

So basically these wearables can use your heart rate to calculate a rough burn, which will not be perfect, but at least when you are comparing the numbers to the devices measured numbers from previous times, it's consistent with itself enough to get an idea of how you're doing.

So if you have ever read about Fitbits not being accurate, it is true. There is no way that this device can measure every little "ism" that causes efficient or not efficient calorie burn. But if your number is higher or lower than a baseline number, like for me going 2.3mph on my treadmill at a 2.5% grade, measuring numbers against that becomes a powerful thing.

And it'll not just measure walking or running. It is still tracking the burn from strength training, sports and more and more activities all the time.

Some of the newer and more expensive models are including a larger variety of activities all the time. The newer models are also able to measure heart rate variability, blood oxygen levels and ECG signals.

I don't personally have any of these functions on my model, but I'm considering an upgrade soon to include them. In which case, once I can see how it affects my thinking and applied knowledge to those measurements, then that will call for a follow-up post to report. I guess I'd prefer to have personal knowledge about it before I would write about it.

But in the meantime, I refer to my tracked exercise information all the time. I enjoy working hard to see higher numbers and I am extremely motivated to keep up with my regiment due to the knowledge that my Fitbit is there keeping track.