Just before the sun fades for the day, Paul and Crystal Wall set out for a little exercise along the bayou trail at Stude Park in the Heights. Their 8-year-old daughter, Noelle, and 9-year-old son, Will, are in tow, along with their niece, Chaslon Bragg, 16.

It is good family time, said Paul Wall, the Grammy-nominated Houston rapper.

Walking is also an effective way to get in some cardio. Sometimes they walk in their neighborhood; other times they hit the park.

Wall occasionally runs laps.

It's been more than a year since Paul and Crystal Wall shared their dramatic weight-loss story with the Chronicle. He dropped 130 pounds after gastric-sleeve surgery in 2010. She lost 70 pounds with Zumba, after trying various diets and even liposuction.

Now, when it comes to fitness, Wall says, "I'm good."

"I'm happy where I am now," said the 34-year-old who once suffered from high blood pressure and even depression due to his weight. "I don't overdo it. We've learned as a family to compromise on what we eat. You can't have all good. You can't have all bad. It has to be something in the middle. We are balancing more."

Wall's fitness stride comes with a career high. "Slab God," his eighth studio album, was released in September and featured the hit "Swangin in the Rain." He says the album is his best work yet.

(Wall, who also serves on the board of trustees for the Grammys, will be attending the award ceremony on Feb. 15 with his wife. )

A mix of Southern slang and funk-soul beats, "Slab God" pays homage to Houston's car culture. Wall's first "slab" was a 1976 Cadillac El Dorado.

The album has kept him pretty busy, with no time to indulge in bad food choices. He admits, though, a love for Tex-Mex food so deep that he could eat it morning, noon and night.

At Stude Park, Wall joins Crystal, 35, and the rest of the family by the swing sets, where a group of children approaches him for a quick "selfie." Another group moves in for its turn, and then two women stop their yoga stretches to pose with Wall.

The rapper says he never wants to get too "full of himself" to forget his fans.

"I love this," Wall said. "I'm proud to be from Texas. I never wanted to be mainstream. I wanted to be the 'hometown hero.' When I was falling in love with hip-hop as a child, that was instilled in me."

Wall also knows he represents a changing and healthier face of hip-hop and rap.

There's a movement in the industry to curb the bad eating and overindulgent drinking. Other rappers, including Slim Thug, Mike Jones, Fat Joe and Rick Ross, have slimmed down significantly.

Wall says his weight loss came with criticism.

"When I lost that weight, my body was the healthiest it has been, but people are mean," he said. "They were so accustomed to seeing me big that they said I had AIDS or was on drugs. That made me feel bad about myself. That's why I'm so open about what I've gone though."

The couple, who met in college at age 21, said they didn't experience weight issues until after they had children.

"We got fat together," Crystal Wall said. "Every time I gained weight with my pregnancy, he gained weight."

In 2013, she opened MixFitz Studios in the Heights and now hopes to franchise the studio nationally.

Crystal Wall has maintained much of her 70-pound weight loss, save for a few extra pounds she plans to shed during her studio's 45-day challenge.

"We are challenging our clients to be their best self," she said. "We offer meal-plan suggestions, and they get points for attending classes."

At the end of the 45 days, which began on Jan. 16, the team with the most points wins a month of free classes at the studio, where Wall teaches dance-based fitness classes with nine instructors.

Last year, she took her MixFitz program to Dallas and Los Angeles.

She says the group dynamic helped her lose weight.

"Most people need a support system. A lot of women didn't see themselves getting any smaller, but we are helping to change their lives. It's not all about being skinny. We want people to be healthy and make healthy choices."

In 2014, Crystal Wall's sister died of sickle cell disease, leaving a daughter, Chaslon Bragg, who is now being raised by the Walls.

"Chaslon came from a household where she ate McDonald's and Popeye's. Our eating habits were so different that it was almost like we were vegans to her."

But through tragedy, the family has become closer and healthier, she said.