Cat Thisius, who plays on the MedCity Mafia roller derby team, takes a breather during a practice Wednesday, April 25, 2018, at the Boys and Girls Club of Rochester. Thisius returned to practice the week before after having surgery to treat her breast cancer earlier this year. "I'm amazed at the progress from this week to last," Thisius said during her third practice back with the team. "Nothing hurts," she said.