Please Add Mountain Biking Activity to the Apple Watch

Apple, please add a “Mountain Biking” activity to Apple Watch. Why should I use an outside app, when you have so many different activity options. Your current “Outdoor Cycle” activity calculates calories count based more off of speed (road cycling), versus heart rate. In mountain biking you will not be traveling as fast as road biking, but it is a HIIT workout based on elevated heart heart rate with elevation gain. I would really like a more accurate read on calories to go along with my mileage count. Thank you!