Just kidding!  biathlon is most certainly a real sport.  Apparently it is one of the most physically demanding sports there is, as your heart rate needs to go from crazy-fast to get the blood flowing to your legs as you skii like a madman, and then within like five seconds slow down to crazy slow so that you can keep the rifle steady and aim.  So while it might seem like you get a rest every once in a while, what is actually happening is you are doing to your heart what a 15 year old learning standard does to a clutch:  jackrabbiting, absolutely destroying the thing.  Go biathletes!