Pools of sweat blossomed through their clothes. Hands on hips, breathing heavily, hearts pounding, the women could not stop smiling. Even though they just finished a grueling, hourlong workout, their spirits were high. These women living at the Genesis Women's Shelter were starting to learn the importance of doing things for themselves.

As victims of domestic abuse, they weren't used to hearing encouragements shouted at them.

But Lin Johnson, the voice behind the supportive words they'd just heard, wants to change all that. She wants these women to feel, for once, that they have power.

"What I try to let them know is they can achieve anything they want to do," she said.

Johnson, along with her husband Jay, trains the Dallas Cowboys Cheerleaders and runs fitness boot camps across Dallas.

Johnson started teaching a free boot camp at the Genesis shelter more than two months ago. For her first class, two women showed up. One was smoking before class began. Even more than the cigarette, what irked Johnson, with her military-infused personality, was that the 8:30 a.m. class started 30 minutes late.

Of course, Johnson understood this wasn't going to be like her regular boot camp, where a late arrival pays the price with push-ups. These women had been through things she can't cure with exercise.

"You can see in the beginning the hurt in their faces," Johnson, 41, said. "Even though they don't say a word about what they've been through."

The Genesis shelter is a place where women go to start over. It is at an unpublicized location, where victims of domestic abuse and their children can show up unannounced and have somewhere safe to stay. It's a place to breathe a sigh of relief.

Rosy Kintzinger, director of residential services, said the ultimate goal of Genesis is to make these women self-sufficient. All women in the shelter and in Annie's House, a transitional housing complex next door, are required to attend individual and group therapy sessions to build their independence.

Johnson, who trained for five years in the Army, hopes to build on that foundation by teaching what she knows best: physical and mental fitness.

The Johnsons have attained celebrity status within the fitness community. Along with their work with the Cowboys cheerleaders, they've appeared on numerous reality shows, including Queer Eye for the Straight Guy and Wife Swap.

The Johnsons took on a hosting role with I Want To Look Like a High School Cheerleader Again, a 2007 show on the CMT cable network in which former cheerleaders fought to get back into shape.

Lin Johnson noticed that producers manufactured tension between the women on the show – a standard practice in reality TV. So after the cameras shut off, she led the women in a workout that ended in a devotional.

For years, she said, she'd been frustrated to see women steadily losing their independence. That certainly included the abused women at Genesis.

She decided to volunteer at the shelter after she saw an article on Condoleezza Rice speaking about women's rights at a Genesis anniversary luncheon. After one phone call, the shelter opened its doors to Johnson and her fellow trainers.

"What more could I give than a free program to women who uprooted everything they had: their entire belongings and a situation they had to get out of," Johnson said. "I just feel like that's where my heart needed to be."

Now every Tuesday and Thursday, Lin or one of her female trainers is on the shelter's sports court, leading whoever shows up that day in an hourlong cardio session of push-ups, karate kicks, laps and more.

"These women are looking for more than just a workout," said Amanda Walls, 29, one of the trainers. "We can tell it's making them feel better inside and out. They're able to do stuff they didn't think they'd be capable of."

For the Genesis women, the emotional benefits intertwine with the physical ones.

"Cheryl," who is in her late 20s, has attended boot camp for five weeks. She said the class gives her motivation she hasn't known in the past. One of her goals since she arrived at Genesis is to be more physically fit. Johnson, she said, is an uplifting presence.

"Jessica," also in her late 20s, said she's glad Johnson pushes her to keep going. She said the boot camp has helped with her depression and "makes you feel proud of yourself, that you're achieving something."

(To protect the privacy of its clients, Genesis asked that pseudonyms be used.)

Health experts note that exercise releases endorphins that can improve your mood.

Jasper Smits, an assistant professor of psychology at Southern Methodist University , said studies show exercise can produce "marked changes" in people with mild to moderate depression – positive effects similar to those of medication and psychotherapy.

"After about 15 weeks of consistent exercise, people start to show signs they're coming out of it," he said.

Smits emphasized that exercise cannot replace medical treatment. But it can help.

Kintzinger, the director of residential services at Genesis, said the needs of women there vary. One recent client, she said, had a steady job as an accountant but was not emotionally ready to live on her own. Most, however, come to the shelter with just the clothes on their backs and often with kids.

Johnson's boot camp is one step in a long road to independence for the women. One goal, Johnson said, is to make sure the women feel it's OK to do something for themselves. And if that means chasing them around the sports court for one more lap, she's going to do it.

The boot camp has a strict, militarized structure. Each exercise is done in cadence, a call and response between Johnson and the women to instill a teamwork atmosphere. Ten miniature traffic cones are set up around the court, each with a foam plate underneath that lists three exercises per station.

Johnson pushes the women. No one takes a break. But at the same time, she's a constant voice of encouragement. She asks if the women can feel the exercises burning in their muscles. She reminds them of how good they're going to feel afterwards, once the sweaty, exhausting part is over with.

"This is one hour just for you, so it's OK to be selfish!" she says.

As the sun climbs higher in the sky and the workout starts to take its toll, Jessica asks if anyone hasn't survived boot camp.

"Can you believe that? We have not killed anybody yet," Johnson answered.

Jessica laughs, setting off for one last lap.