Greta Goplen stood in position with a cane at the ready, like a ninja warding off invisible foes.
As an instructor yelled out directions to the class — "left, left, jab, jab, nose! right, right, jab, jab, nose!" — the 59-year-old raised her walking stick and nimbly thrust it out kung-fu style, swinging it to either side before jabbing it backward.
Half an hour later, the class ended. A dozen women quickly sat down to rest artificial hips and arthritic knees.
"But I'm not done killing yet," Goplen said, bashing an imaginary mugger on the ground. "We got 'em! Yeah! Yahoo!"
Exercise for baby boomers has gone trendy.