Activity app shows no active calories burned under workout tab

I have the Nike series 3 watch. When I run with just the watch and use the NRC app, my iphone activity tracker app doesn't register any active calories burned under the workout tab for the run. The watch does appear to be tracking my active calorie burn correctly as the move ring does show calories burned during the run. Also the move calories are correct under the history tab on my phones activity app. Why aren't the active calories being recorded under the workout tab on my phones activity app?