I know it's silly to ask for 100% accurate for indoor running but I would expect my 645 is at least as good as my old 630...
Have been using 645 for half a year now and all runs were outdoor. Because of the recent bad weather, I ran a couple of runs on the treadmill this week. The first time I ran 5 miles at 7:30 pace but my 645 showed I ran 4-ish miles at about 9 min/mi. Frustrated. I stopped my watch and did the calibration, then tried it again and it went to another end - in a 4 miles run it showed I ran 4.5 miles.
Yesterday I ran again with my old 630 - in a 3 miles run it showed exactly 3 miles. Very accurate even though I haven't used it for half year.
My understanding is the 630 learns your running form and pattern during your outdoor running when GPS is available, calibrate itself so when you go to indoor it can tell your pace by the arm swing pattern using the internal accelerometer. Everything was automatic and I didn't manually set anything. Is that no more the case for 645? Anything I can do to make my 645 better?
Thank you!
