STATE COLLEGE, Pa. (AP) - It's time again for another grueling test of stamina at Penn State University.

It's "Thon" weekend.The annual 46-hour dance marathon best known as "Thon" runs from late Friday to Sunday afternoon at the Bryce Jordan Center in State College.More than 700 dancers take part, helped by thousands of other students in support roles. The dancers can neither sleep nor sit.The event's official name is the Penn State Interfraternity Council/Panhellenic Dance Marathon, and it's billed as the world's largest student-run philanthropy.Money raised benefits pediatric cancer patients and their families at the Penn State Milton S. Hershey Medical Center.Child cancer survivors and their families also take part.Over $13 million was raised last year, bringing the total take since 1977 to more than $125 million.