Pedometers: Walking by the numbers
According to the national Centers for Disease Control and Prevention, programs promoting step goals--such as walking 10,000
steps per day--can encourage people to exercise enough to reap health benefits.
The aim, the CDC says, is 30 minutes of moderate exercise, five or more days a week. All steps count, whether up a mountain
or around town, as long as they’re brisk enough to boost your heart rate and you walk for 10 minutes or more.
A pedometer keeps track of steps for you. It also can be a good motivator, found a study released in June 2004 by the American
College of Sports Medicine. Participants who used pedometers added about 2,000 steps per person per day to their routine.
All this makes the pedometer sound like a great gadget. Too bad that many are inaccurate at the slow speed favored by people
beginning to walk for exercise.
We tested 12 basic pedometers (they count steps) ranging in price from $12 to $55 and 3 speed-and-distance monitors (they
track pace) that cost from $100 to $200. We asked eight volunteers to wear pedometers while walking on a treadmill at 2.5
mph (equivalent to a 24-minute mile) and 3.5 mph (a 17-minute mile) and compared the devices’ step counts with actual counts.
We also assessed durability with an apparatus that cycles up and down to simulate walking. To test speed-and-distance monitors,
we checked distance readings after walkers completed a measured course. (If distance is accurate, speed will be, too.) And
we looked into the features you’ll need in a walking shoe (see our October 2004 report, Walking shoes: Fit and features).
Only three basic pedometers were accurate within 5 percent at 2.5 mph, and only one of the speed-and-distance monitors provided
the accurate distance within 5 percent. Most of the other devices were off by 5 to 10 percent, and a few pedometers were off
by 20 percent or more. The worst were so inaccurate that if you walked five miles, they might say you’d covered three to seven.
At 3.5 mph, the pedometers did far better: All but one were accurate to within 5 percent. They also proved durable. All were
still counting after the equivalent of 500,000 steps, or about 250 miles.
How to choose
Your first decision will be which type of device to buy (see Pedometer or speed-and-distance device?). Other decisions follow:
Consider how you exercise. If your goal is simply to track how far you’ve gone during your day or on an exercise walk or run, an inexpensive pedometer
will do the trick. If you want to know your pace, a speed-and-distance monitor is the right choice. If you like to hike, consider
a speed-and-distance monitor that uses the Global Positioning System (GPS).
Consider the features you want. Some devices, noted in the Ratings, have a stopwatch function so that you can time your workouts. Some have a clock, handy if you aren’t wearing a watch; some
have backlighted displays, nice if you walk at dawn or dusk; some have a pulse meter. Some pedometers will count calories
if you program in your weight and sometimes gender, age, and height. All else being equal, models that ask for more information
provide a more accurate calorie count. Some speed-and-distance monitors beep when you go above or below your target speed.
Consider comfort. Pedometers are easy to clip on, but any model’s accuracy can suffer if the unit isn’t worn just right. (See Pedometer or speed-and-distance device?)
Some people may find the wristwatch speed-and-distance devices bulky or the shoe-attached device distracting.
Consider convenience. Try before you buy. Programming pedometers can be as easy as entering your weight and stride length, but you may think you
need a math degree to program some GPS devices. And those work only in the open air: A roof or deep woods can block the signal.
Most pedometers make you scroll through the display to read step count, distance, and calories. More convenient models show
data and time at once.
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