Reshaping pilates: Tidal wave of popularity changes the regimen's precise movements.

Byline: Julie Deardorff

The Saturday morning Piloga class began in a way that would please most traditional yogis _ with meditative breathing. But as the cross-legged students exhaled deeply, the experience morphed into pilates.

"Drop your abs towards your spine," instructed Randi Whitman, owner of Chicago's Frog Temple Pilates studio. "Pull your rib cage away from your pelvis."

For the next hour, the Piloga students flowed between the distinct disciplines of pilates and yoga, two of the fastest growing "soft" exercises in the fitness industry.

For Whitman, blending the two mind-body practices has become more than a treasured creative outlet. Yoga and pilates _ a routine of exercises using mats or equipment that strengthens the muscles surrounding and supporting the body's core _ are necessary complements.

But to Chicago's Juanita Lopez, one of the first pilates teachers in the Midwest, the mere concept of "Piloga," which can also be called Yogalates or Yogilates, is a dreadful adaptation of the real thing.

"You can't mix and match," she declared. "One can benefit the other, and they're both classic systems, but if you mix, you …