Despite my misgivings about the Garmin 405 (see here), I love the data it generates -- particularly after I discovered SportTracks and its ability to slice and dice the data. Because I run so many miles on a treadmill, I wanted the footpod so that I could track the indoor runs as well. A Garmin 50 -- which comes with a footpod, a watch, an extra heart monitor and extra USB stick -- is about $100 on ebay, whereas the footpod is $70. So I bought the Garmin 50 (except I got the world's worst deal at J&R). Note to all Garmin 50 buyers -- a Garmin 50 is actually sold in three different packages -- watch plus footpod; watch plus heart rate monitor; and watch plus heart rate monitor and footpod. I thought I was buying the third (all 3), and ended up with the watch and a footpod, but no heart rate monitor. And I spent more than I would have if I had bought the package on Amazon or ebay. And to boot, the battery in the footpod was dead out of the box. Garmin owes me 15 minutes of my life back trying to get the footpod to synch with the watch when the battery was dead, even though both were brand new.
Anyway, the footpod tracks the movement of your foot and sends the signal to your watch. Garmin suggests you calibrate it on a known distance such as a track. It does not recommend calibrating it on a treadmill.
On Saturday, I had a plan. I wore my Garmin 405 on left wrist which tracks distance on GPS. I wore my Garmin 50 on right wrist and footpod on. And I ran a course I have run before with a known distance. Thus, I could calibrate my Garmin 50 with the GPS distance generated by my 405! I was laughably geeked up running out the door -- two watches, a heart rate strap, a footpod, an iPod and headphones. (And a new pair of Gel Kayano 15's to boot.)
To cut to the chase: the Garmin 50 was consistent with my 405. Over a 5.8 mile course (previously measured by my 405), my 405 (GPS) had the course at 5.81 miles. The Garmin 50 (footpod) had the course at 5.9 miles. My single heart rate strap sent data to both watches and the data was identical. One interesting thing was to note that pace recorded by GPS (blue) was both slower and had greater variance than the pace recorded by the footpod (red):
So the Garmin 50 is pretty well calibrated out of the box. The Garmin 50 has many limitations, again frustratingly so, but I won't deal with those here. (For example, during a workout, the watch can't cycle through various data displays. Any basic treadmill cycles between, speed, distance, calories, etc. But not the 50 -- have to hit a button to change between heart rate, pace, distance, etc.) But I digress. My first gym workout with the footpod (pre-calibration) had a 5.1 mile run as measured by the treadmill come out to 5.25 miles on the footpod, and had me running on the treadmill at a significantly quicker pace (footpod had me approximately 0:40 seconds per mile faster than treadmill). Maybe I do "run" faster than what the treadmill measures and that is why I perceive I run faster in real life than a treadmill: I run faster in real life than on a treadmill because I actually run on a treadmill faster than the belt measures.
But anyway, aside from my overly teched out gear, it was a good run, and really wiped me out.