A pedometer is a small device used to count how many steps a person takes while walking. Experts recommend taking around 10,000 steps per day to improve physical fitness. Since most people cannot spend their entire day counting their steps, a pedometer acts as a sensible way to monitor and relay such information. Traditional pedometers include moving parts that indicate each time the wearer's hips move while taking a step, while newer digital models can track foot movement and include calculations for distance traveled.
Basic pedometers consist of a mechanical sensor that counts steps by taking into consideration how much the body shakes. An internal ball or similar object moves up and down with the motion of the person wearing the pedometer, effectively sensing the vibrations of his or her feet hitting the pavement through hip movement. As the ball moves, it activates a switch that in turn clicks the counter forward. Simply shaking the pedometer gives the same result, even without walking, which shows how the device works.
There are also digital devices that use more advanced programs to monitor and gauge a person's movement over time. A software application inside such a pedometer keeps track of the number of steps the wearer takes. Internal gyroscopes and similar hardware help track movement, and precision may vary based on manufacturer. More advanced models can also convert steps into miles or kilometers, based on the average stride length of a wearer, and calculate calories burned.
To be able to measure correctly, a pedometer should be worn straight and vertically, preferably attached to the wearer's belt. This helps the device identify hip movements correctly and keep accurate track of how many steps the wearer takes. It is unlikely that any pedometer on the market is 100% accurate, but more expensive digital models can be quite close to the mark. Wearing the pedometer correctly also improves its performance. Despite what some companies may advertise, most pedometers do not accurately measure steps over time when placed in a pocket, purse, or backpack.
Some companies produce pedometers that are integrated with personal electronic devices such as mobile phones and digital music players. Many of these devices include clocks and timers, as well as additional information relayed through a Global Positioning System (GPS) to track location and overall distance traveled. These pedometers still require the user to attach the device to his or her body, and some may include additional items such as shoe sensors. This can ensure a more accurate reading, based on actual foot movement, though much like other models, overall accuracy can vary depending on each device.