The 19th annual Twin Cities Marathon takes place this Sunday.The 26.2-mile course begins near the Metrodome in Minneapolis and finishes at the State Capitol in St. Paul. 85 runners have competed in all 18 previous Twin Cities marathons. 73-year-old Mary Lou Carlson is the oldest female runner of this elite group. Carlson's husband inspired her to start running. He took up the sport while she was in her fifties... at first she thought he was crazy...especially when he ran in the winter.