PJ Heffernan owns a Waukesha-based yoga studio called PJ's Yoga Shala, but don't confuse his practice with a traditional business.

"I always felt very uncomfortable with the business of yoga. Yoga is not a business," says Heffernan. "It is not a religion. It is not an occupation. It is a cultural art form."

Heffernan's classes have suggested rates, but students pay what they can afford. Heffernan calls it a "karma system" of payment in which he trusts people to pay a fair amount. Most of his students, he says, pay the suggested rate, but he will make adjustments. Most importantly, Heffernan wants yoga to be accessible to anyone, not just the wealthy.

"Everyone needs this authentic yoga," he says.

To make yoga even more available to the masses, Heffernan offers a free yoga class every Sunday afternoon at 1:15 p.m. at Invivo, 2060 N. Humboldt Blvd.

Heffernan teaches a style of yoga called Ashtanga, and his practice is the only Ashtanga school in the Midwest.

Ashtanga, which means "eight limbs," incorporates a sequential order of poses and combines breathing, postures and gazing points to help practitioners reach his or her "fullest potential on all levels of human consciousness."

Classes at PJ's Yoga Shala range from beginner to advanced.

"I even started a class I call Hips and Spine which is as basic as it gets. You don't even have to be able to stand up for that one," says Heffernan.

At the age of 15, Heffernan started taking yoga seriously, and by the time he was in college, he took eight yoga classes a week.

"That's when I realized I could really take control of my body," he says.

Heffernan studied yoga in Milwaukee at the Milwaukee Yoga Center and in Chicago with a teacher named Gabriel Halpern. However, by 2005, he was teaching so much that he began to feel removed from the practice.

"I felt a little lost and craved a challenge, so I sought out the one person in the country who I thought had the most inspiring physical asana practice I had ever seen," says Heffernan. "That man was Richard Freeman."

Heffernan drove to Colorado to study with Freeman, who introduced him to the Ashtanga style of yoga. On his last day of study, Heffernan asked Freeman what he should do next, and Freeman suggested he travel to India.

So, on New Years Eve in 2005, Heffernan traveled to Mysore, India to study with Shri K. Pattabhi Jois, the founder of the Ashtanga Yoga Research Institute. Jois was 90-years-old at the time and had been teaching this ancient system of yoga for 70 years.

Heffernan studied with Jois four different times in the past four years, and plans to make his fifth trip later this year.

"The practice there begins at 4 a.m. Ashtanga morphed everything about me. It took away a lot of anger and sadness," says Heffernan. "It has been the most humbling, powerful, transformative thing I have ever done."

Heffernan believes yoga's mainstream popularity is both a blessing and a curse. He says that, unfortunately, the yoga craze cranks out less-than-qualified teachers.

"I think it's a shame how yoga has been dumbed down into an exercise fad. To be honest, there are very few qualified teachers out there. People want to be teachers before they are students. This is yoga's greatest adversary," he says.

However, despite some reservations about local yoga instruction, Heffernan believes everyone benefits from a yoga class because it simultaneously empowers and humbles, destroys ego and fear, makes a person strong, flexible, more agile and happy, and it "destroys poisonous delusion in the mind while detoxifying the body."

"Most of all, yoga is good for us because yoga means unity," says Heffernan. "Anyone that says they hate yoga is saying that they hate unity."