Back in hilly Pacifica again, and walking. This time, I fired up a pedometer app on my iPod Touch and did some step counting. (6,000 for a morning stroll.) Counting steps is all the rage these days, but this little jaunt got me thinking. And not just about "step by step...inch by inch..."
Pedometers have been around for a long time. Nowadays, of course, they're widely integrated into other devices such as iPods and SmartPhones. Dedicated (more or less) pedometers are now typically worn on the wrist (think FitBit for example) making them very convenient.
But is counting steps a good measure? It definitely misses some things.
- Steps are not all created equal. In particular, they don't take grade into account, as in walking up or down hills. 1,000 steps on flat terrain is much easier than 1,000 steps up a steep hill. To some extent, that might be offset by the hilly steps being shorter and so requiring more steps to go the same distance (maybe). But that brings up the next point...
- Step counters aren't very good at distance. A pedometer takes an average stride length and multiplies it by the number of steps to estimate distance. The stride length defaults to one based on height; you can measure your own to get a more accurate value. But even this will offer limited accuracy; for example, on hills, the stride length shortens so the distance will be inflated. (Stride length generally only lengthens when speed increases, and for some people not even then.) Some step counters may also use GPS. More on this later.
- Back to the hill thing (I'm in Pacifica, after all)...step counters estimate distance but don't even guess at elevation changes. As noted previously, that can make a big difference. Once again, GPS can help.
- Step counts are biased toward shorter people. Two people walking the same distance (and the same grades) who weigh the same do the same amount of Work, as defined in physics (Force x Distance). Yet a shorter person, with a shorter stride length, will take more steps. So if high step counts are the goal, there's a height bias.
As mentioned, I was using an app on my iPod. I don't have a FitBit or any other wearable step counter. I do, however, have an old Garmin Forerunner. It looks more like a huge, clunky watch with extra display data, but it also has a GPS in it. This allows it to measure distance and elevation along with time (which means it can calculate speeds). GPS isn't spot-on accurate, but it beats estimating based on steps and stride length.
(The Forerunner also has a heart monitor, as do some of the modern higher-end wearables, although the Forerunner uses a separate chest strap while some wearables take the pulse from the wrist.)
My Forerunner is almost four years old. So it's much bigger and clunkier than a modern device would be, and its displays are boring at best. But it works.
I prefer to know how far I went (including elevation changes) and how fast (seeing my average current speed is a nice feature too) rather than just the number of steps taken. That's especially true if I'm hiking in the hills or out for a run where each "step" is different than a usual walking stride.
So is counting steps worthwhile? If it gets people moving more, that's a big win no matter what gets counted or measured. I don't keep up with all the wearable technology but there may be some "step counters" that include GPS for tracking distance. Devices like the Apple Watch sync to a SmartPhone (in this case, an iPhone of course) to use its GPS. But if you went, say, two miles, why does it matter how many steps it took? Isn't knowing how far you went (with a reasonable degree of accuracy) and how long it took (and, if relevant, how much elevation was covered) much more important?
I forgot to bring my Forerunner on this trip. I could use a site like mapmyrun.com to check my distance (although there were a lot of curves along the way) and see how it compares to the step-counting app. But it doesn't really matter to me. I took a walk. It was good. Yay.
Be seeing you.
-gary