|
I've used the older Nike TRX system with footpod, the more recent Nike+ and the Polar625X with the footpod and the G1 GPS arm sensor. That combination does not record location data. I understand that the newer RS800CX system with the G3 GPS does and the file can be uploaded to Google Earth.
I've also run with the watch in tandem with a separate Garmin eTrex handheld. Interesting, the sensitivity and accuracy of the running sensor and the dedicated GPS are similar. The eTrex information is, obviously, more detailed and can be viewed in their proprietary software (MapSource) as well as Google Earth. Since I do not vary my running routes that often, I generally map them once so the separate GPS works fine for that.
As a measuring device, I prefer the footpod over the GPS in certain situations--heavy overcast, running in thickly wooded areas or a combination of these. With a fair amount of fine tuning, you can get the accuracy of a foodpod to a good level.
In addition to the sensitivity issues, the nature of GPS measuring can create issues. The best illustration I've heard goes something like this: let's say you are on a 1/10th mile circular loop and you run it at a 10 minute per mile pace. That means you will pass the starting point every minute. Suppose your GPS updates every 1 minute (actually, most update every few seconds). On that basis, every time it takes a reading you will be in the same spot. You can run ten miles but your GPS will tell you that you haven't moved an inch.
This can be an issue if you run a route with a lot of curves since the GPS will draw a straight line between two readings and can, over the course of a long twisty run, trim out a measurable part. (I lost about 2 tenths once on a winding trail run.)
Also, let's say your GPS takes a reading and then you enter heavy woods and the unit loses contact with the satellites for several minutes during which you make a long turn and emerge from the woods nearby where the GPS regains contact. It will connect the last contact reading with the next one and "cut the corner" of your long turn.
That said, I like the GPS unit on clear days and, especially, clear nights.
njp
|