When personal trainer Kelly Brabants launched her eponymous fitness and lifestyle brand Booty by Brabants last year, the North Easton native found herself teaching the class of her dreams—in workout gear she hated.

“A lot of the activewear on the market just didn’t have the stretch I needed,” recalls Brabants, whose trademarked rump-roasting cardio class blends Brazilian dance, classical ballet and kickboxing. “I’d have clients stop in the middle of a squat to pull up their pants or take a break because they had a huge wedgie. Nobody likes it, but that’s what’s available.”

Brabants aims to change that. With the popularity of her classes at an all-time high—even the Associated Press recently popped by for a trend piece—the fairy godtrainer to Boston’s superlative derrières is adding apparel to the lineup. Her first offering: leggings manufactured in her mother’s hometown of Rio de Janeiro.

Made from fast-drying, super-breathable material, the leggings are designed to be durable (enough to handle the class’s 120 squats) and stylish too, with a body-flattering construction that comes in nearly a dozen colors, including “Acai” (dark purple) and “Copacabana” (deep blue). “So often people look like robots at the gym. Everyone is wearing the exact same thing,” Brabants says. “Brazilian women don’t do cookie cutter: It’s about vibrancy and expressing your individuality.”

If the popularity of the first lot is any indication, Brabants may have struck gold with her clothing debut. She sold 15 pairs from her gym bag in 10 minutes after a Saturday class. All 30 were gone by the day’s end, leaving some counting down the days until the early December launch of her e-commerce site at BootyByBrabants.com.

But for Brabants, the bottom line isn’t strictly financial: Inspiring confidence in her students is the greater goal. “Sometimes people imagine every woman you’d pass on the streets in Rio must look like Gisele Bündchen, but it’s not like that,” she says. “Brazilian women aren’t perfect—but they embrace what they have. People are healthy, but they don’t obsess, because they’d rather enjoy life. I’ve applied that approach to my fitness brand, and it’s that same fun and positivity I try to bring into the apparel.”