Do supermodels have really strong legs?

My guy friend thinks that super models are skinny and really weak. However, last week, his girl friend saw Marissa Miller working out at her gym in LA and she was doing some pretty heavy weights on the leg press 450lbs doing multiple reps and sets. They got to talking and Marissa said that all the super models you see now a days work out religiously and are insanely strong for their build. Seems that they have to be that fit to do all the cat walks in sky scraper heels. Do you think that's true?