JACKSON -- On a recent sunny weekday, five women do repetitive lunges and biceps curls while singing disco songs interspersed with children's songs. They race across grass fields pushing wide-wheeled strollers, and are told to run up and down several flights of stairs, which they do, willingly. They even show up a second, third and fourth time for more.

Welcome to Stroller Strides, a national franchise of fitness programs for caregivers and babies that opened its first Wyoming shop earlier this year.

Julie Linahan, 34, brought the program to Jackson to fill a community need.

"It's for any mom looking to be active with their baby," she said.

The classes typically involve babies and toddlers in strollers and mothers trying to work out and keep their babies happy by singing songs or offering toys. Some, like Lindsey Viveiros, 24, bring children for whom they are caring.

"We come as much as possible," Viveiros, a nanny for a 10-month-old, said. "It's active, it's something outdoors, and she's getting to know kids her age. It saves me a trip to the gym."

Lisa Walker, 31, decided to join Stroller Strides to get in shape after her baby, Niko, now three months, was born.

"It's a priority for me to get in shape," she said. She said the class works for her because she can meet other moms, and other moms understand if you have to stop the workout to care for the baby.

With the cost of babysitting in Jackson ranging from $8 to $15 an hour for one child, the one-hour Stroller Strides class also helps moms save money on sitting.

Linahan, along with daughter Aundra, nine months, brings rubber tubes and balls for moms to develop strength training as well as a cardiovascular workout. Moms run from one station to the next, pulling on tubes through a fence, doing push ups and sit ups, and other combination exercises born from Linahan's 15 years in the fitness industry.

And for moms concerned their baby will be fussy during the workout?

"Usually," Walker said, "they all melt down at the same time."