The woman on the phone at Crunch gym in Danville had a pressing question: Which shoes should she wear to work out: low or spike heels?
"Whatever makes her feel more fabulous," said Shab Jaleh, a former professional cheerleader and aspiring Persian pop star who is teaching a new fitness class: Stiletto Strength.
The hourlong class starts with floor exercises to strengthen the calves, ankles and abdominal muscles, then finishes with 20 minutes of strutting, cat walking and simple dance steps in high heels. It's BYOH.
"What I'm really teaching is posture," Jaleh said. "It's a class for women who want to learn how to walk, dance and look hot in heels."
Donna Cyrus, a senior vice president of programming for Crunch, created the classes in 2007 to help well-heeled New York women become more nimble navigating the pitted streets and subway stairs. Since then the classes have spread to Miami and Los Angeles, and premiered in Northern California in Danville on Jan. 4.
"It's not a fitness class in high heels, it's a class to teach you how to walk safely in high heels," Cyrus said.
Still, podiatrists are shuddering.
Dr. Colleen Schwartz of Pleasanton, spokeswoman for the American Podiatric Medical Association, said there is a right way and a wrong way to approach heel fitness classes.
"You really are risking Achilles injuries if you start out in the highest heels," she said. "It's better to start out with lower heels and work up to the stilettos after at least three weeks."
She also advises wearing heels home instead of switching to tennis shoes, so the transition is not so jarring on the muscles. Foot-strengthening Pilates classes are also a good idea.
"Ultimately, from a medical standpoint, I'd say these classes are a disaster, but this is a trend and women, including podiatrists, wear heels, so it's important to wear them wisely," she said.
The health debate over pumps is long-standing, as is the desire for women to wear something that makes their legs look slimmer, said Mindy Kreis, the group fitness coordinator at Danville Crunch.
"Heels aren't going away any time soon, so it's better to learn how to walk in them properly so you don't get injured," she said.
Stiletto Strength fits in with Crunch's repertoire of edgy classes, Kreis said, noting a roster that includes pole dancing, videography to teach dances from popular music videos, a strip-tease class and yoga done to rock music.
Kreis, who used to train the Warrior Girls, said women are tiring of basic aerobics classes and looking for ones with a little more kick.
Jaleh, who lives part time in Los Angeles, takes a "hip-hop in heels" class there that's taught by a man.
After Jaleh led seven students through a series of lunges, plies and calf raises set to an ear-splitting Shakira song, "She Wolf," it was time to put away the mats and slip into stilettos.
Brittany Miller, 23, of Danville could hardly contain her excitement as she zipped into 5-inch, thigh-high black leather spike boots.
"I got them for the Lady Gaga concert a few weeks ago, but I've never danced in them," she said.
Jaleh put on a Miley Cyrus song at nightclub volume, and the students tried to mimic her horse-prance steps across the floor.
"One, two, three, up!" said Jaleh, taking three steps, then lifting her foot off the floor in a deep bend on the fourth count.
"Stay on your toes! Right! Left! Cha-cha-cha!" she instructed, showing her charges how to take each step leading with their hips.
"As long as you touch the floor with your toes, and not your heel, that's the trick," she said.
Jaleh, who has cheered in heels for the Golden State Warriors, the Oakland Raiders, the Sacramento Kings and the San Francisco 49ers, floated across the room as if she were born with sticks attached to her heels.
Nobody fell, but there were several wobbly moments.
"It's like Pilates, but faster," said Danielle Giambrone, 24, of Castro Valley.
Miller, who has plans to become a professional cheerleader, sees the classes as a form of training.
"You learn how to hold your body in heels," she said, "and it definitely brings out your sultry, vixen side."