Calories during "Navigate" Activity Confusion

I recently move and created a bunch of "courses" using Garmin Connect on-line since I wanted to run these exact routes and not get lost :eek:. After syncing I noticed that "navigate" is recorded as "other" activity which isn't a big deal; however, the calories are way lower than when I use "run" as an activity for the same distance. I changed "other" to "run" using Garmin Connect thinking that might help; however, the calories did not change. E.g., navigate for 5.21 miles = 354 calories, run for 5.18 miles = 720 calories. Does anyone know why this is and/or how to fix it? Thanks in advance.