The other women in class curled dumbbells as they lunged. But Lindsay Macaleer put down her weights and instead gently rocked her double stroller to soothe her 2-year-old and 10-week-old sons.
"I just want them to be quiet, so I'm modifying my workout," whispered the Arlington, Va., resident, who was grateful to be back into her exercise routine at all.
For Macaleer, 34, that's three days a week taking either a Stroller Strides class, which combines high-intensity aerobics and strength-building moves, or Stroller Barre, which borrows sculpting techniques from ballet and Pilates.
Both offerings are available through Fit4Mom, which was known as Stroller Strides until this summer. The 12-year-old program, founded in San Diego and now at 275 franchises across the country, has gradually expanded to incorporate prenatal fitness, classes for moms without their kids in tow, and moms' social clubs focused on nights out rather than working out.
So it was time for a name that better reflected that breadth, says Susan King Glosby, Fit4Mom's vice president of operations.
"We're about strength for motherhood and being fit, regardless of what age your kids are," she says.
That might sound like an obvious goal. But the fitness industry, despite being propped up by millions of women trying to lose that baby weight, hasn't been particularly inviting to moms. Child care often isn't available at gyms, and even where it is, kids usually have to be at least 6 months old to be accepted.
"No one wants to wait six months to exercise," says Jennifer Lungren, who has welcomed plenty of new moms to her Fit4Mom Arlington-Alexandria franchise in Virginia over the past decade.
And once they find a place where they can bring their brood, chat with other moms about their latest sleep woes and meet up with playmates, they get hooked. That's what kept some of Lungren's clients showing up for years, through more pregnancies, preschool and beyond.
Other mom-centric fitness programs have followed a similar path. Baby Boot Camp got its start in 2002 when the San Francisco gym where founder Kristen Horler was a personal trainer didn't have child care. So Horler strapped her baby daughter into a stroller and organized a group of mom friends to meet up in a park. Now there are 154 Baby Boot Camp franchises.
"I can't tell you how many women have told me they wish it had been around for their oldest children. I wish I had it," says Nicole Marville, who has led the Montgomery County Baby Boot Camp franchise in Maryland since January. (Like Lungren, she has four children.)
Traditional gym settings can be especially intimidating for new moms dealing with unfamiliar body issues. Fitness instructor Kathy Corbey recognized the need for an alternative way to work out when she gained more than 70 pounds with her first baby. She spent six years developing her mom-baby classes at rented spaces around Northern Virginia before opening the Mommy Bootcamp studio in Ashburn, Va., in 2012.
Just off the 4,000-square-foot fitness area is an open playroom where kids 18 months or older can read, color and frolic. Babies stay in strollers closer to Mom -- or even hang out in carriers during low-impact exercises.
And whether she's taking Hot Mama! (Zumba-esque cardio dance) or BOOTY-camp (which focuses on glutes and core), there's no problem having kids who act like kids.
"Moms always call and ask, 'What if my baby cries?' It's Mommy Bootcamp. It's expected," Corbey says. "No one is going to judge you or give you a dirty look."
They might, however, pass over a snack. At least one box of raisins changed hands at Lungren's Stroller Barre class last week, which drew about 15 women -- including Macaleer.
After a quick warm-up, the group took off with their strollers for a lap around the parking lot. The frequent intervals of jogging or walking aren't just for boosting heart rates, Lungren explains. The kids get antsy when they're parked in one spot for too long. So Lungren made the most of each pause, launching right away into exercises like plies with shoulder presses and squat pulses.
Singing kiddie hits, playing peekaboo and encouraging the children to count along with the reps holds off the inevitable meltdowns. Moms rave that these techniques also help engage the kids, so they're learning during class, too.
"My 2-year-old and 4-year-old push their baby doll stroller around, and then they stop to do push-ups and mountain climbers," says Meagan Buczek, beaming.
The 35-year-old mom is 22 weeks pregnant with her third child, but that's not keeping her from attending classes -- and also instructing three a week.
Her stamina is all the more impressive when you recognize how hard all of these women are working. Katie Ford, 34, could barely get through her first Stroller Strides session last year. The mother of two had just moved to Arlington from Britain, where she'd tried Buggyfit, an English program designed for "mums." But while that was focused on merely getting up and moving, her new class motivated her to really push herself.
"I've never been this strong, even when I was in the military," Ford said.
The results, both physical and mental, can make classes not just effective, but almost addictive, several moms said.
That's why Michelle Egorin, 36, is concerned about the future. She has been a devout Stroller Strider for nearly seven years, since her son was 3 months old. When he went off to school, Egorin's daughter took over the stroller seat.
But now that her younger kid has turned 4, Egorin is considering signing up for a gym membership. Everywhere she's taken a tour, though, has left her unimpressed. She worries that, instead of getting to interact with mom, her child will be plopped in front of a television at a gym day care.
And Egorin would lose her best exercise buddy. "It seems so boring to work out by myself."