Audri Pettirossi’s breathing grew shallow. She started to feel as if she was floating out of her body. She was having a panic attack, which she said had become a regular experience for her. Ms. Pettirossi knew what she had to do.
She opened her laptop. It was time for Tae Bo.
In a video she later posted on TikTok, Ms. Pettirossi, wearing pajamas, punched and kicked the air in time with women in sports bras and low-rise yoga pants on her computer screen.
Her doctors had told her movement could help her manage panic symptoms, she said. And since discovering the old-school workout on TikTok, Tae Bo has become part of her go-to routine.
Tae Bo, a cardio workout combining taekwondo, boxing and aerobics made popular in the 1990s by the martial artist Billy Blanks, is seeing a resurgence online.
Ms. Pettirossi, who is 22 and lives in Vermont, is one of many people born years after the fitness program debuted who are now turning to Tae Bo videos and recording their workouts on social media.
TikTok is providing an even bigger audience for Tae Bo than its ubiquitous infomercials, DVDs and cassette tapes did — and introducing the workout to a new generation. “Now I’m getting a second chance,” Mr. Blanks, 70, said.
“Exercise has to be fun,” said Nikki Fraser, an exercise physiologist in Toronto. “Whatever makes you excited and motivated to keep going back, that’s the kind of exercise you should do.”
In the original videos, Mr. Blanks is usually dressed in a tight tank top and silky boxing shorts and leads a group of mostly women through a series of punching, kicking and twisting sequences. He cries, “Work it! Work it! Work it!” between the group’s cheerful eight-counts. Everyone is slick with sweat and smiling.
“Even though we were working out hard, we were having so much fun with doing it,” Mr. Blanks said.
Most new Tae Bo converts are working out with Mr. Blanks on YouTube, where many of his old videos have been uploaded in full. But some are digging out old DVD and VHS players and buying Tae Bo tapes at thrift stores.
“Everyone wants to go back in time,” said Weslande Jean Baptiste, 36, who remembered Tae Bo from infomercials she had watched as a child. “We just want things that are much simpler.”
She was drawn to Tae Bo in November, she said, because it required no equipment and was free on YouTube. She does the workouts five to six times a week at her home in Cleveland and has been recording her progress on TikTok. “Now I see why everyone was running to the stores buying his DVDs,” she said.
Mr. Blanks, a seven-time karate world champion, developed Tae Bo while he was training in the 1970s. His goal was to get more women involved in martial arts, and he found that adding aerobics made the sport more appealing to many of them.
After he started training his first famous client, Paula Abdul, in the 1990s, lines formed outside his studio in Sherman Oaks, Calif. More than 100 participants often filled each class, he said, where celebrities and athletes punched side by side with grandmothers and teenagers. When Mr. Blanks started filming workout videos, he said, he hoped to replicate the energy of his studio workouts and scale it to televisions across the country.
In his videos, Mr. Blanks addresses the viewer directly, offering modifications and pointers while repeating “Good job!” At the end of most workouts, the group cheers and joins hands, forming a glistening chain of muscles around Mr. Blanks.
Emma Latouche, a 28-year-old Pilates instructor in Melbourne, Australia, has done Tae Bo several days a week for the last month, noting the infectious energy of Mr. Blanks.
“It feels like you’re a part of it, even though there’s 20 or 30 years’ difference between when it was filmed and then just watching it on YouTube,” Ms. Latouche said.
Ashlynn Miller, 23, used to do Tae Bo with her mother in the living room of her childhood home in Iowa. She was scrolling on TikTok a few months ago when she came across someone her age trying Tae Bo. “I was like, man, I haven’t done that in ages,” she said.
Ms. Miller decided to give it a try and posted a video of her third attempt at the workout. Her comments were flooded with notes of encouragement. “I’m a Year 2000 Tae Bo Lady. It’s hard work but it’s worth it!” one user commented. “Original Taebo girlie!” another wrote. “So glad to see it’s making a comeback. Keep up the great work!”
Ms. Miller said doing Tae Bo helped her feel closer to her mother, who passed away three years ago. And now, her own 14-month-old daughter watches her do the moves in their living room — and sometimes she cheers along.
Mr. Blanks, 70, still teaches Tae Bo classes daily from his home in Los Angeles. He regularly hosts live workouts on TikTok that draw thousands of participants and has a Tae Bo app in the works.
“People are going, ‘Wow, Billy Blanks is back,’” said Mr. Blanks. “I’ve never been gone!”