When Cassey Ho fused traditional Pilates moves with pop music and uploaded a video of her exercise class to YouTube, she had no idea she was starting a fitness revolution.
Now, even pop star Taylor Swift is a fan and Ho is the owner of an entirely self-funded health and fitness empire, with her YouTube channel Blogilates at the center.
Ho, who calls her POP Pilates workouts a "dance on a mat," told CNBC's "Street Signs" that the secret to her success was making exercise fun.
"Once you start making exercise fun it becomes a lot less about the reps and losing weight, and more about having a good time," the 29-year-old Vietnamese-American says.
Blogilates, which Ho launched in 2009, is currently the number one female fitness channel on YouTube, having clocked up more than 300 million video views and over three million subscribers.
Ho also owns POPFLEX Active, a line of activewear, and has authored a fitness and wellness book called "Cassey Ho's Hot Body Year-Round." She also publishes free, detailed monthly workout plans, meal plans and recipes online at www.blogilates.com.
In 2015, Cassey forged a partnership with gym chain 24 Hour Fitness to offer POP Pilates as the official Pilates format in 24 Hour Fitness gyms across the U.S., alongside other favorites Zumba and Turbo-Kickboxing.
The trainer's girl-next-door appeal and upbeat attitude has made her a serious social media influencer, with fans - who call themselves POPsters - ranging from young girls to grandmothers.
"I think it's important to put positive content that helps to bring value to my fans' lives," she says. "You have to have a purpose - make sure you are giving something of value to somebody other than yourself."
Her popularity was evident in Singapore on Sunday, when she led a POP Pilates class at the Zespri SunGold Kiwi Fest fitness day - more than 3,500 people took part. It's as part of a regional tour that's already taken her to Sydney and Kuala Lumpur.
POPsters are now watching for the Fall 2016 collection from POPFLEX, and Ho hints that something even more exciting is in the works.
When asked by CNBC who her own favorite YouTube stars were, Ho names musicians Kurt Hugo Schneider and Sam Tsui, and reveals there may be plans to incorporate their music into her workout videos, saying "something might be coming up."
Despite her phenomenal success, however, Ho remains firmly down to earth, admitting it felt surreal when she learned that superstar singer Taylor Swift knew who she was.
"She looked at me, saying, 'Cassey, I watch your videos'," Ho, who had been invited to Swift's house for a fan meet-and-greet, recalls of the moment two years ago.
Ho says that Swift is top the list of people she'd like to feature on a Blogilates video. Given everything else Ho's managed to achieve, don't rule it out.