Poutanen, just curious which GPS watch you are using and do you know how it is logging coordinates? 1 sec. or 1/2 sec. intervals. Or do dedicated GPS receivers handle things entirely different than phone app GPS does?
Looking to school my ignorance here,..
It's a Garmin Forerunner 410, and it doesn't have a set interval for logging. They claim it has a "smart interval" that decides when to log based on calculations.
From what I've read, the intervals can be anywhere from 1/2 a second to 5 seconds or so.
For what it's worth, the apps I used recorded raw GPS data from the phone at intervals that I told it to, and I uploaded that data to Garmins website, so I'm comparing apples to apples as far as how the data is interpreted after it's recorded.