in shape or die?

Ok so you ever watch the show the biggest loser? Hate to admit it but I do. Officially makes me a reality tv watcher I suppose. Well these people have to get in shape or literally they could die. Now I battle my weight like many of us do but not quite to that extreme. But I have done some reading and the days these big folks put in is amazing. With being recently laid off I am working out most every day and on some days twice it's killer. Not sure how they do it