Gov. Jim Doyle signed a bill Monday allowing fitness centers in Wisconsin to offer female-only classes and workout space.

The Democratic governor said health clubs including the popular Curves chain should be allowed to legally discriminate based on gender despite concern from some Democratic lawmakers that the bill might backfire against women.

"If this bill can help encourage women to lead healthier lives and to exercise by offering a supportive environment, then it deserves our support," Doyle said during a signing ceremony at the Capitol.

The governor said Senate Bill 24 is similar to laws in Illinois, Alaska, Massachusetts and Minnesota that allow women to work out free from the glances and attitudes of men.

"Fitness is a very private matter," said Brenda Swanson, owner of Curves centers in Edgerton, Stoughton, Oregon, Janesville and soon in Maple Bluff. "Just like we have the choice to be able to choose where we want to go for a physician, this is going to allow us that choice for fitness."

Eleanora Theiss, 86, of Sun Prairie, who works out three times a week at Curves, also attended the signing ceremony.

"If you have men in there, it somehow puts a more competitive spirit in it," she said. "And I'm beyond the age of competing with men."

But Rep. Terese Berceau, D-Madison, said the bill could be abused and potentially set back equal rights for women.

"It appears there is a difference of opinion as to how widely this bill could be interpreted," Berceau said. "I think we'll just have to wait and see (if unintended consequences occur). But I think the door has been opened a crack."

The flip side of the bill is the legalization of male-only health clubs. But Doyle said he's confident the bill will not lead to male- only golf courses.

"This is limited to fitness centers," Doyle said. "I believe the definition of the bill is tightly drawn."

Curves owners face 173 sex-bias complaints filed with the state's Equal Rights Division by a La Crosse man who says the chain is biased against men. A spokesman for the governor said the bill doesn't void those complaints.