A forearm heart rate monitor has been one of my regular training accessories over the past few years.
Although the data it provides during strength-focused sessions aren’t particularly useful—the primary energy system used during those sessions doesn’t depend upon oxygen or, subsequently, heart rate—knowing my heart rate and being able to compare it to how I subjectively feel during endurance-focused sessions has helped me adjust my effort (and sometimes rest) on the fly and experience greater results from my training time.
Recently I’ve become a bit more interested in tweaking my non-workout habits such as sleep, steps, and general daily activity in an effort to improve my recovery and results. So a few weeks ago I (finally) jumped on the bandwagon and purchased a smartwatch.
If you’ve considered doing the same, I definitely recommend it. The experience of both tracking and observing data changes (e.g. step count, HRV, sleep quality) based on daily habit adjustments (e.g. intentional breaks for movement, earlier final meal of the day) has been fun so far.
Of course, the watch is still just a tool. And like any tool, it has its pros and cons. Here are a few based on my own observations and past discussions with others:
Pros of fitness trackers
They improve lead measures: A lead measure is something we do in order to achieve an outcome, or lag measure. For example, eating fewer processed foods or walking more are lead measures that might contribute to the lag measures of weight loss or improved cardiovascular health, respectively.
Studies have shown that tracking something (i.e. a lead measure) is one of the simplest ways to motivate ourselves to do more (or less) of it. The process of tracking focuses our attention on what we deem to be important and ignites our natural tendency to try to beat prior “scores”.
Since the point of using any type of fitness tracker is to, well, actually track what we do, then using one is highly likely to cause us to improve upon those actions.
They make outcomes and trends easier to observe: What did you eat for dinner two weeks ago? Yeah, I have no idea what I ate either. I can, however, look back through the app that’s connected to my watch to see how many steps I took, what other exercise I did, when I went to bed, and how much I actually slept.
The point here is that our minds aren’t useful for remembering small, daily details. But those details are exactly what produce the results we experience. Using a tool to automatically track what we did and then display data from an extended timeframe in graphical format enables us to see trends and make better decisions to improve long-term results.
They gamify the process: We all love to have fun and play, and we often want to avoid the grueling activities that we don’t enjoy (although there are potential benefits to doing those things anyway).
Tracking apps create a type of game out of the process by showing streaks and using bright colors, screen “splashes”, and haptic feedback. That causes our brains to release dopamine whenever we take the actions being tracked.
All of which motivates us to do more of those tracked lead measures which then produce the lag measures we actually want.
Cons of fitness trackers
They’re not completely precise or accurate: It shouldn’t be surprising that a medical grade blood pressure cuff (or a nurse) tracking your heart rate in a quiet, motionless environment is going to be more accurate than a device that uses light reflected through the back of your forearm while you’re moving. Or that the device’s accelerometer or calorie algorithm might regularly miscalculate steps or energy use.
But it can still be easy to fall into the trap of following the tracked data like gospel.
This doesn’t mean the data are worthless, but rather that we should take it all with a grain of salt. If we overlay the tracker’s data with how we feel in the moment and the results (i.e. lag measures) we experience, we’re more likely to make better decisions than by trusting the tracker’s data alone.
They’re algorithmic: Piggybacking a bit on the last idea, this one is meant to emphasize that we each have individual differences that won’t be completely reflected in the device’s advice algorithms.
As an example: If you’ve been following along you know I spent the previous two weeks summiting Grand Teton and Mount Elbert as well as doing some additional climbing and hiking. Based on my activity levels, my watch said that I was overreaching (which leads to overtraining if it remains chronic) for most of the previous 17 days and am now, three days after returning home, in a state of detraining.
While that might be accurate if we zoom in to the razor’s edge of cardiovascular performance, it’s simply not reality from a practical standpoint based on my decades of training (i.e. exercise) experience. And it completely discounts strength-based results.
Ultimately, all of this is simply data and isn’t an issue in and of itself. That said, it can easily lead to falling into the trap of the third con if we’re not careful.
They can promote obsession on the outcome instead of the process: I saw a comic not too long ago that showed one character telling a friend what his fitness tracker said about his heart rate, caloric burn, cardiovascular health, etc. during his workout.
The friend asked, “But did you have fun?”
To which, the first character looked at his tracker and replied, “It doesn’t say…”
As I described above, fitness trackers do have benefits. But the primary point of those benefits is to help us make better decisions about the actions that might improve or maintain our health and fitness in the real world. If we get lost in the data, we risk making our health worse by stressing out about unimportant details and not benefitting from the joy that activity provides.
Putting it into practice
Any type of fitness tracker, from a heart rate monitor to a watch to a scale to a DXA scanner, is simply a tool. And just like a hammer and drill are good for their respective tasks and not so good for the other’s, fitness trackers have their place.
So take full advantage of their benefits when or if you use them. But for the best results, also remember to filter the data they provide through the lens of your experience.