To see how these products tracked athletes' movement, we covered some ground. We logged literally thousands of miles, mainly on foot. Whether those feet were in running shoes, mountaineering boots, or backcountry ski gear, our testing was real-world and comparative. We would regularly wear and compare multiple contenders on the same endeavor. However, to truly get a feel for each device we made sure to use each one exclusively for at least a week of training.
Our lead test editor, during the multi-year testing period, tackled his most ambitious training regimen ever, logging an average of seventeen training hours a week, for one forty week period. He also visited six countries on two continents and travelled more new-to-him miles than in any other period of his life. Throughout these entire three years the lead tester has maintained that same 17 hours of action a week average. Virtually every one of the lead tester's abundant training and active hours was monitored by one or more of these GPS/Training watches. After this much usage, only a few objective comparison tests were necessary. Specifically, each tested model was used to measure the distance on a known track in order to assess accuracy. Also, we made sure to run each GPS watch tested from full to zero battery in order to test and compare it to the manufacturer's claim of battery life.
Ease of Use
In simply using the devices, and sharing them with a broad and deep test team, we developed and distilled a significant body of use experience. Our opinions are based on years of experience and at least weeks of using each device.
We compared each product to a list of potential features. Our list of features is a combination of hardware and software inherent in the device. Some devices are also further customizable. The list of potential features we compared against is time keeping, GPS distance and speed, GPS data recording, GPS navigation, step count, sleep tracking, built-in heart rate, compatibility with external sensors, barometer, thermometer, and smart watch functions.
We evaluated each device's GPS distance measurement on a standard running track. Each device was subject to at least two test rounds of .50 miles each. Reported inaccuracy is the average percent deviation of the watch results from the actual distance.
Ease of Set-up
In configuring each device we monitored steps required, clarity of device, app, and paper instructions, and the time required. Time required includes active time setting up and passive time awaiting initial sync.
With a wide range of variables, objective battery life testing of GPS watches is problematic. We gathered anecdotal evidence in usage of each device, weighting our impressions for the niche or niches the device is optimized for.
Mainly, portability is a function of size. Larger watches are less portable and smaller ones are more portable. We measured and weighed each one.