Tuesday, May 10, 2016

about 21,000 steps

I forgot my phone this morning. Had to go back and get it. The trip to work, even when I go by subway (which I always do in the morning), racks up at least 1,000 steps. In retrieving my phone, I probably racked up another 2,000 steps thanks to the round trip to my place and back. I also took one of my ten-minute walks with my coworker before I went off to see the torture doc for my followup visit: another 1,000 steps. So that's about 4,000 steps in all before I recovered my phone.

Tonight, my pedometer puts me at 17,163 steps—7.67 miles walked, 1201 calories burned. At 171 minutes (2.85 hours) of walking, that's a step rate of slightly over 100 steps per minute, which is back to where I want to be—not stuck in the mid-to-high 90s.

I also decided to perform a test to see how accurate my pedometer is. As I walked, I watched the meter markings on the path, then used my stopwatch to time myself while I marched 200 meters. As the stopwatch ran, I mentally counted my steps. Result:

Time to walk 200 meters: 2:24
Number of steps: exactly 250

I also did another 200-meter stretch, this time watching my step count on the pedometer.

Distance: 200 m
Steps: from 5689 to 5956, i.e., 267 steps (Maybe I'd sped up...?)

By my count, if 200 meters takes me 2:24, then 1,000 meters = exactly 12 minutes, which comes out to 5 kilometers per hour. Multiply that by 0.62, and that's 3.1 miles per hour.

If my pedometer says I'm going 7.67 miles in 171 minutes, then that translates to 2.69 miles per hour, which I know is bullshit. As I hypothesized, my pedometer has been shorting me. If it's been shorting me on distance, then it's likely been shorting me in other ways as well, such as walking speed. (Since the formula is d=rt, this means distance and velocity enjoy a directly proportional relationship. Be stingy with speed, and you're being stingy with distance.)

Conclusion: while I trust my pedometer's step count, I'm walking both faster and farther than the pedometer will admit—about 13-15% faster and farther. So if the pedometer says I did 7.67 miles today, I actually did about 8.82 miles—almost nine goddamn miles, and that's not including my extra 4,000 steps, i.e., 1.98 miles. And if the pedometer says I walked 13.64 miles yesterday, then in truth, I walked 15.7 miles.

Eat that, you sneaky Samsung-pedometer bastard.



Charles said...

It's all a Samsung plot to get you down, man.

John Mac said...

I tried several pedometers from both the Samsung apps and Google Play Store. I've finally settled on one (aptly called "Pedometer") that is simple, gives me a running total of steps on a daily, weekly, and monthly basis. I can't attest to its accuracy, but it provides me a baseline for measurement.

Can't imagine ever reaching the coveted 30,000 step milestone. I start dragging at around 2.5 hours and just run out of gas shortly thereafter. Maybe over the course of an entire day with a long morning and long evening walk, but I'm not motivated...

brier said...

I have to agree with the comment John made about Google store's 'pedometer' app. It isn't that bad, it counts my steps accurately (within 1 or 2%) and you can adjust your step length, weight for caloric burn, and sensitivity to step counts. But where it goes wrong is with the speed calculation. I walk about 100 or 105 steps per minute, but the app says that is only about 4km per hour. I have done some math on my step length, count, and time and I should be about 5km per hour. I don't understand how the app can get one set of numbers right, but the set wrong.