When I teach a new group of students, I introduce some yoga philosophy, but I don't overload them with information. Just enough so they understand the real tradition behind this ancient practice and that it's not a stretching class. Guys come in and they're a little nervous. I tell them that when they cross the threshold of the door, they're crossing to a different dimension. They're moving from an externally-oriented reality to an internally-oriented one.

I'm not fearful by nature, but I am vigilant. When you walk into a prison, it's important that a sixth sense kicks in.

Sensitivity is equated with weakness. Feelings are for women. It's OK to express happiness or anger, but it's not OK to feel fear or sadness. This gets exaggerated in prison.

When you're on the yard, prisoner politics dictate that you only socialize with your own race. If you fraternize with other races, you can get taught a painful lesson. And there are inmates with a level of consciousness who feel it's their duty to enforce this segregation.

Yoga class is intimate even just from the standpoint of taking off your socks. Exposing your bare feet can be a big deal. You may be an African American next to a Caucasian or a Latino. But once practice begins and we drop in, separation dissolves.

I teach that the foundation for our practice is being able to go inward and disconnect from the busyness of our thoughts, that focusing the mind on bodily sensations and breath will ground us in the present moment. Yoga is about realizing who you really are, aside from your persona.

Since the late 1970's, the main focus of prisons has been punishment, not rehabilitation. It's hard to believe, but you would be hard-pressed to find a meaningful violence-prevention class in a federal or state penitentiary. And 'we the people' are footing the bill to keep these folks imprisoned. It costs on average $46,000 a year to keep an adult incarcerated in California and about the same for New York State.