Skier's Edge is a downhill indoor ski training and conditioning machine (skiersedge.com). It would be nice if Strava would support this as a new activity. Time, heart rate, machine setting (downhill, moguls, etc) and difficulty level could be captured. Calories can be calculated post work out based on the workout difficulty, person's age, weight and **bleep** too (which Strava has).
The machine is used by recreational skiers, the US ski team as well as many international teams as a conditioning tool during the off season.