Figured it out. You must have step counting on in all devices for Garmin to subtract Activity Steps and not double count them.
I learned this the hard way. I have both the Vivosmart and ForeRunner 920XT. I use the VS for step tracking, and the FR for exercised. I keep the VS on 100% of the time, and the FR goes on only during workouts.
Since I wasn't using the FR for step tracking, I turned activity tracking off within the FR. . . BIG MISTAKE.
Immediately, I started getting extra calories during my exercise. I couldn't figure out why. Then I did some tests.
I turns out that Garmin uses the Step Count from within the ForeRunner to subtract from the daily total from the VS to avoid double counting during Activities.
Example:
I have 5,000 steps and 100 calories in VS. I go on a 1,000 step walk with my FR + VS, logged as an activity in FR, and earn 100 calories as Hiking.
If I have step tracking turned ON in FR, I get 200 total calories. My Daily Totals Screen will show VS's 6000 steps. . . 1000 for the Hike and 5000 for the Daily Steps.
If I have step tracking turned OFF in FR, I get 300 total calories. My Daily Totals Screen will show VS's 6000 steps. . . 0 for the Hike and 6000 for Daily Steps. I will get 100 calories for the Hike, and seperately 100 calories for the 1000 steps.
