MADRID—When Clara Colome's small business failed in Spain's grinding recession, she picked up the pieces with a little help from her friends, "Pandemonium" and "Hell on Wheels."

Those are the nicknames of her teammates on the Black Thunders Derby Dames, a local roller derby team that is part of a global boom in the full-contact skating sport. Ms. Colome, who skates as "Heidi Maiden," says that roller derby lifted her out of the doldrums by giving her renewed self-confidence as well as a sense...