I was in one of those in Steamboat Springs Colorado a few years back.
This biathlon was like the Olympics, on skis. You skied a 1 km course and then took 3 shots. One km on cross country skis is enough to get you panting real good.
You had to ski the course 3 times. The targets were 3 inch sugar cookies glued to a piece of cardboard.
That was fun!