The Wahoo Fitness Stride Sensor is a three-axis accelerometer foot pod worn on your shoe. It transmits data to any ANT+ compatible receiver. Using it with the Fisica sensor key for the iPhone or iTouch, there are dozens of apps to use to see your speed and distance. The sensor works indoors, outdoors, treadmill, sidewalk, or trail. It works right out of the box without need for calibration. I found it very easy to use and it produced great data. The integration with sites such as NikePlus.com and MapMyFitness.com also allows you to store and view your workouts, maps, etc.
This is the lowest-priced Forerunner that uses GPS to measure distance and speed. It gives you distance and time on one screen, pace and calories on a second screen. It's easy to use and it auto-pauses when you slow to a halt. It has a great Virtual Pacer function to keep you up to your chosen speed. If you like doing run/walk intervals, it will time them. It also beeps at the end of each mile and automatically tracks laps. You can see a history of your past seven activities. You can upload your data to the Garmin Connect site to see your activity on a map and see your average and best pace. But unlike more expensive Garmins, you can't add a footpod or heart rate monitor.
3. GPS-Based Mobile Apps
If your mobile device includes GPS, you can use any of several apps to display your real-time walking speed. They work best when you are in a flat area, away from hillsides, buildings or tree cover, you are carrying the phone in an exterior holder, and you are moving in straight lines. I have found the speed to be too dependent on the GPS signal and the ability of my iPhone's GPS antenna to pick it up. Take several measurements before you start trusting the data. Because they use GPS, they won't work for the treadmill and won't be reliable indoors. Some of the apps that I have used are:
This pedometer sensor transmits data wirelessly to an iPod nano, iPod touch or iPhone. You can view your data and get voice updates at milestones as you move. It is meant to fit into Nike+ ready shoes such as the Nike Air Zoom Plus and the Nike Air Zoom Moire. You will want to calibrate it to your walking and running strides on a course of known distance to get the best accuracy. It uses an accelerometer rather than GPS, so accuracy varies if your stride varies. It works indoors or outdoors. While the 5th generation and newer iPod nano includes a pedometer, that function only counts steps. If you want speed and distance, you need the Sport Kit. There are many GPS-based apps for the iPhone, but the sensor works where GPS doesn't.
True speed and true distance provided by a GPS unit. This is spot-on speedometer and odometer is accurate no matter what you are doing - walking, running, skating, skiing, biking, etc. It continuously measures your speed and distance to three decimal places, and has sports watch functions of chronometer, lap timer, alarms, countdown timer, and more. It's all included in one wrist unit without a separate GPS sensor, although you can add a foot pod sensor or bike sensor. You can pair it with a heart rate monitor. It downloads via USB to your computer to view your workouts.
This is an expensive unit, but it has the ability to do it all except show you an actual map. You just wear the wristwatch with GPS built-in. You can add the optional footpod (to work where GPS won't) and heart rate monitor strap. You can see your speed, distance and other workout data on the touchscreen. It has all kinds of lap tracking, a Virtual Partner to pace you, Virtual Racer to race against your previous time, pace and distance alerts, pointers back to your starting locations, plus downloading your workouts to your wirelessly to your PC or Mac. There, you can view your workout on a map and see all of your data. The watch works for up to eight hours in training mode before needing a recharge, which might get you through a marathon.
7. Polar RCX3
Polar keeps evolving its speed plus distance system. The RCX3 is designed for recreational athletes and Polar picks it as good for walkers and Nordic walking. For speed and distance readings, you can use it with their s3 or s3+ stride sensor footpod or switch to their extra-small G5 GPS sensor. With the sensors being separate from the display watch, the watch itself is thin but with a large number display. Naturally, it connects with a Polar heart rate monitor strap to track your heart rate. It has Polar's ZoneOptimizer technology to adjust your heart rate zones automatically. Use it with the online polarpersonaltrainer.com and the GPS sensor and you can also view maps of your routes. It comes with a big price tag.
This multi-function watch does more things than you can shake a stick at. It has a built-in accelerometer and displays speed in miles per hour, as well as counting workout steps, estimating distance and calories burned. It has a finger pulse monitor and also comes with a chest strap heart rate monitor. With the interval training function, you can hone your training by distance, speed and heart rate.