Photo: Eddy Chen/Black Bear Sydney Sweeney put on a reported 30 pounds of muscle to play boxer Christy Martin, the subject of Christy , turning her body from red-carpet willowy to one with a sturdy solidity. The movie begins in 1989, when Martin was just out of her teens and fighting in Toughwoman contests, and spans 22 years, providing all sorts of opportunities for ungainly period hairstyles, from a ragged pageboy to a curly mullet to a frizzy shag. Sweeney also goes mostly makeup-free for