Revision as of 08:09, 11 November 2015

A comparison of various Footpods, from top left to bottom right): Garmin (Ant+), Adidas MiCoach (Bluetooth), i-gotU (Bluetooth), Polar S3 (W.I.N.D.), Polar Stride Sensor (Bluetooth). You can see the Polar Footpods are huge compared with the others.

A Footpod is a small device that measures pace and distance while running or walking. These Footpods contain accelerometers that calculate the movement of your foot, providing an accurate measurement across a broad range of paces and stride lengths. A Footpod does not simply measure each stride, which would be wildly inaccurate. If you have a Garmin Watch then a Footpod is an excellent upgrade.

1 Accuracy

Out of the box, a Footpod is typically accurate to 90+% and after calibration this typically improves to 98-99%. This compares well with the accuracy of GPS which is 97-98%. However, a Footpod only gives you this accuracy on smooth surfaces where your stride is reasonably predictable. You need to make sure the Footpod is well attached to your shoe; if it's bouncing about the accuracy will be poor. If you do trail running, I found the accuracy can be rather patchy. Of course if you're running a twisty trail with tree covered, you may find the accuracy of GPS dropping to 80-95%. I have found that a Footpod provides vastly more accurate information for your current pace compared with GPS. While the errors in the GPS signal even out over the course of a run, they can result in a current pace that is inaccurate by 1-2 minutes/mile.

2 Calibration

You can calibrate a Footpod against a known distance, or against GPS. In both cases a longer distance will provide greater accuracy as small variations will even out. I have written a Garmin Foot Pod Calibration utility to simplify the process. Calibrating against a known distance is far superior to calibrating against GPS because GPS has its own level of inaccuracy.

3 Footpod Position

To get the most accurate reading, make sure the footpod is in the same position each time you use it. Moving the footpod around will change the calibration factor, as will changing to a different type of shoe.

4 Cadence

The Footpod will provide an accurate display of your Cadence, which is a critical and often overlooked aspect of running.

5 Using a Garmin Footpod

If you have a Garmin 910XT, 310XT or 610 then it is possible to display your Pace From A Footpod while getting other data from the GPS. I believe this is the optimal configuration for most runners. In addition, I found that turning the GPS off and relying on the Footpod dramatically increases the battery life of a Garmin watch.

6 Bluetooth Footpods

There are a number of Bluetooth Footpods on the market, but there are various compatibility issues.

7 Troubleshooting

There are relatively few things to go wrong with the foot pod.

• Make sure the Footpod is attached to the same position on the shoe each time you run.
• The Footpod needs to be reasonably well attached so that it moves with your foot. If it's flapping around you get inaccurate readings.
• The most common problem you have with the Footpod is a low battery level. A low battery warning should be displayed on your Garmin watch, but I've had problems before the battery warning was displayed.
• If you're still having problems after replacing the battery, then the Footpod has probably failed. See below for details.

8 Footpod Failure

I've found that the Garmin Footpods consistently fail after about 12 months of use. This is around 4,000 miles of running for me, but I don't know if the failure is due to the distance covered or the time. The initial symptoms are similar to a low battery, with the Garmin watch having problems detecting the Footpod. If you replace the battery and still get connectivity problems, then you may have a failing Footpod. The key symptom I've found is that the Footpod starts reporting an unreasonable pace, such as running a 3:00 min/mile pace. I've also had the Footpod cause the GPS to think I'm no longer moving, so the distance display does not increase and the average pace drops steadily. I'm now on my fourth Footpod and I've had to accept that they are consumable items.

9 RunScribe

RunScribe make Footpods that measure a wide range of biomechanical data in addition to pace and Cadence, including Braking G's, Impact G's, Ground Contact Time, Foot Strike, and more.