When 24-year-old yoga instructor Lindsay Istace was going through a bad breakup, she noticed that her negative emotions seemed to flow into her practice. Instead of calmly finding inner peace as she moved through her asanas, the Calgary-native found herself cursing up a storm in between poses.

"Suddenly my at-home practice started to quite naturally adopt a lot of swearing and a lot of yelling. At first it seemed kind of ridiculous," Istace told INSIDER. "After a while, I noticed that pairing a yoga practice together with something that felt like catharsis... was incredibly helpful."

Sessions are held in the basement of Dickens Pub in Calgary, Canada. Online classes will be also available starting this summer, so that people from all over the world can join in on the rage.

Istace never thought Rage Yoga would turn into such a phenomenon when she started it in January; she just thought it was a great way to introduce a new sort of yoga into her community. "I started with a one-off workshop," she explained. But after she received multiple requests for more classes, she decided to transform Rage Yoga into a regular practice.

With a soundtrack of punk and metal music — anything from System of a Down to Nine Inch Nails — and the option for yogis to drink and scream to their heart's content, the class is drawing in a lot of people who typically stay away from traditional yoga. After all, the class encourages them to swear during breathing exercises, instead of silently concentrating.

"We’re getting a lot of people that otherwise would not go to yoga, as well as people who have a preexisting practice but want a less serious approach," Istace said. "It’s a different attitude. If people actually just want to joke while they’re going through asanas or whatever, they can. It’s a much more laid back, easy-going atmosphere."