Every day for lunch I walk a half-mile to a café. I get a bite to eat, then stroll back to work.
Recently I began thinking about my daily routine. How long does it take? Ten minutes each way. Does it tire me out? Not really. How many steps do I take? Huh—I’m not sure.
Here’s where my pedometer is useful. This little gadget tells me how many steps I’ve taken over a given amount of time—but not by paying attention to my feet. Instead, it relies on the vertical movement of my trunk that happens when I walk.
A simple pedometer worn on your waist uses a mechanical, or spring-suspended, lever arm, which bobs up and down with each step. When the lever hits a metal contact, it closes an electrical circuit. Every time an electric current flows through the closed circuit, a step gets recorded.
Such a basic device, however, doesn’t tell me everything I want to know. Do I pace faster on days I’m hungry? What’s the average number of steps I take in a week?
Like many of us, I carry the answer with me. Today’s smart phones don’t use levers. They count steps with accelerometers, tiny electronic devices that sense changes in motion. Smart phones can also track location through a variety of inputs, particularly GPS.
No step-counter, whether on your waist or in your phone, is fully accurate, especially if you carry your phone in your bag, like I do. Next walk, I’ll keep count in my head so I can check the accuracy of both my phone and pedometer—every step, after all, gets me closer to lunch.