Tracking devices: what’s useful?

About three months ago, I got the new Garmin Forerunner 645 after dealing with some issues for about 9 months with my old Forerunner.

The 645 is an amazing device on many levels. As a running device and fitness tracker, it measures about everything you could imagine that something simply strapped to your wrist can. It’s not perfect at everything but what it can do is pretty amazing.

That said, there have been plenty of reviews of this device. This is not about the device itself. It’s about the usefulness of all the things our watches can track these days. As I’ve stated before, all of this data can be a blessing and a curse.

The Forerunner 645 measures a ton of things, both while running and while not running. While running, it measures (obviously) time, distance, and pace. As well, it measures your heart rate, altitude, the temperature at your wrist, and probably some other things I’m forgetting. While not running, it measures everything you would expect from a modern fitness tracker: steps, floors climbed, heart rate, and probably other things I’m forgetting. It also has a stress score, based on a proprietary calculation using your heart rate and heart rate variability (HRV).

This is an amazing wealth of information. So much that it’s easy to get lost in the data. That was a problem I was concerned about years ago when we had far fewer data points. Now, it’s something I’m even more concerned about.

Some of this data is incredibly useful. Some of it much less so. As always, all of it can be a distraction if not used carefully. I’d just like to take a run through some of what can be tracked with modern devices and how I’ve found it to be useful or not in my first 3 months of experience with the 645.

While running

As I’ve stated before, on the run, most of this data is simply a distraction. We know that listening to your body is the best way to track how you’re doing on the run.

That said, there are some data points I’m finding useful after the fact to analyze how the training is going or confirm what I think happened on a run. I won’t cover the basics of distance, time, and pace. These have been around for a long time. My thoughts: even with these, I limit what I can see during the run. For well over 90% of my miles, I only let myself look at distance covered.

Heart rate: I’ve played around with a heart rate monitor many years ago with poor results because I payed too much attention to it while running. However, by simply recording it and not looking at it during the run, I’ve found it does a good job of confirming how I felt a run went or not letting me lie to myself. Combined with pace and especially looking at time in each zone, it gives a good picture of my current fitness level and how fatigued or rested I am. If I’m running slowly and my heart rate is high, I know something is up. Maybe the weather is rough (heat/humidity definitely affect heart rate), maybe I’m fatigued from recent training. Then it’s just a matter of being honest with myself about what is up. Likewise, if I’m cruising with a relatively low heart rate, that tells me things were going well. I was well rested, the weather was favorable, things just aligned.

These are things I usually know without this tracking but it’s good to have a confirmation when I’m questioning whether I need to modify my training and to keep myself honest. I’m sure we’ve all encountered situations where things didn’t go great but we tried to convince ourselves it all went well. This can serve as a reality check in such situations.

Cadence: I actually had cadence/stride rate tracking on my old Forerunner. I’m not one who believes you must run 180 steps per minute. In fact, I think trying to hit an artificial number is harmful. I do keep an eye on my cadence but I don’t get a lot out of it, other than it drops off when I’m fatigued. What did I expect?

Again, somewhat useful as a confirmation of what I already know or a reality check to keep myself honest with myself.

Wrist based temperature: Now, this is an interesting one. I thought it would be completely useless. Again, it doesn’t tell me anything I didn’t already know but I’ve seen an interesting correlation. When my wrist based temperature (different than air temperature because it’s against my wrist so it’s usually higher) gets up to around 80 is when I really start feeling the heat. Again, I know when I’m feeling the heat but I’ve seen in workouts where things got real tough and I was able to see that the wrist based temperature was going up. Confirmation that the heat was getting the best of me.

I already once found myself looking over a workout, thinking it went badly, then seeing the temperature rise just as I knew I began struggling. I should have known I was struggling with the heat but, again, we sometimes don’t give ourselves credit for what we were facing. This gave me a different perspective on how the workout went.

While not running

Steps: This is something interesting to see and I have actually taken some action on what I’ve seen. I’ve realized how little I walk throughout most of the day on most days and I’ve tried to change my habits based on what I’ve seen. I make a point to not always take the most convenient route but instead go for a bit of a walk at different points in the day.

Has this changed my life? I doubt it. Has it helped me be more healthy and feel better? Well, I can tell you that, after I walk a little farther, I do feel better. I think it’s made a marginal difference.

All day heart rate: This is an interesting thing to see. It sheds some light on how much stress your body is under. As we all should know, the higher your morning resting heart rate, the more stressed your body is. Resting heart rate is one of the most clear measurable indicators of overtraining. If you see an upward trend when you’re training hard, that’s something to be aware of and you should be watching for other signs of overtraining.

All day stress: This is an interesting improvement on just measuring heart rate. Heart rate variability (HRV) is a hot topic right now. The greater your variability, the less stressed you are. I’ve been able to track my all day stress score and it really is a good indicator of how rested I am.

Again, not information I couldn’t otherwise get but it confirms what I know and keeps me honest with myself.

Floors climbed: To be honest, I don’t pay much attention to this. It’s interesting to see but I don’t do anything with it or take action on it. Personally, I’ve found this to be pretty useless.

Sleep tracking: Again, something I had on my old Garmin. Essentially, it measures how much you move while you’re sleeping and, based on the movement, tells you how much time you had in deep sleep and in light sleep. I haven’t really done much with this and I find the all day stress score to tell me more.


So what does all this long post tell us? Essentially, I’d sum it up as this: If you’re paying attention to your body, one of these devices is not going to tell you much you didn’t already know. However, it does in several ways force you to stay honest with yourself. At times, we all try to convince ourselves that what we’re feeling isn’t really what’s going on. All of this tracking, used correctly, can correct you if and when you go down that path.

Is all of this tracking necessary? Absolutely not.

Is it interesting? For a person like me who is naturally drawn to numbers, absolutely.

Is it overwhelming? It absolutely can be and this is something we need to guard against if we’re going to use one of these trackers.

Is it useful? If used properly, it could be.

Is it too much? If you’re not careful, yes. You could easily get lost in the numbers and forget to listen to your body.

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