Matt Fitzgerald discusses the differences between the various speed and distance devices available, and helps you find the one that will work for you.
Before you can train with a speed and distance device, you have to own one. The purchase of a speed and distance device is one you’ll want to make carefully. These tools are not cheap, so it’s important that you know as much as possible about the model you favor before you take it home, lest you suffer from $150 or more worth of buyer’s remorse. There are significant differences between models, and none of them is every runner’s favorite. You will greatly increase the odds of purchasing a device you’re happy with if you first educate yourself about all of the major brands.
There are five important factors to consider before making your purchase. Let’s take a quick look at each.
GPS or Accelerometer
Some speed and distance devices use global positioning system (GPS) technology to generate pace and distance data. Others use accelerometer technology. GPS-based devices are more convenient because they do not require calibration, as accelerometer-based devices do. In addition, GPS-based devices allow you to map your routes, whereas accelerometer-based devices do not.
Accelerometer-based devices have advantages too. They tend to be significantly more accurate than GPS-based devices on running tracks. Also, unlike GPS-based devices, accelerometer-based devices can be used both indoors (on treadmills) and outdoors.
A select few units can be converted from GPS-based to accelerometer-based and vice versa. For example, the Garmin Forerunner 305 is sold as a GPS-based device but you can purchase an optional foot pod that converts the unit to an accelerometer for use on tracks and treadmills.