I do my long distance runs on a Garmin 945. I walk around all day long (and sleep) on a Garmin 235. Both watches are set to GPS and GLONASS satellites. My 235 is configured for Activity Tracking, not for runs. When I finish a run my 945 tells me I have gone 7 miles and burned, say 615 calories. My Garmin 235 tells me I have completed a 9 mile run and burned 800 calories. Why, pray tell is my 235 handing me less than accurate numbers?