Notes
Interesting feature on the Garmin 235. Run Indoors had done a decent job of estimating my distance, and I assumed it used accelerometers or something. Instead, I now think it simply calculates a stride length from your last Outdoor run, and uses that with your cadence to compute distance indoors (e.g., on the treadmill). Yesterday, I ran a Half Marathon at 7:36 pace, so my stride length was probably a bit longer than normal. The Run Indoors feature said I ran 9 miles today (versus 7.44 mi indicated on the TM), so it must have used the most recent outdoor data to update what it believes my stride length to be, resulting in a large error in today's actual mileage.
I wonder if there is a way to "calibrate" the Run Indoors feature so that it doesn't always overestimate my mileage. I believe my stride length on the TM is shorter on easy runs than it is on comparably easy runs outdoors.