NEW YORK (Reuters Life!) - When one of Meera Patricia Kerr's students tried to attend a regular yoga class the instructor told her to come back when she lost weight.
"That kind of broke my heart, said Kerr, a yoga instructor and author of "Big Yoga, a Simple Guide for Bigger Bodies."
"Overweight people feel out of the loop. If you're big you might be uncomfortable in a class of 'normies,' " she said, even if the instructor is welcoming.
Kerr says some yoga teachers don't know how to adapt to bigger bodies.
"There's fitness yoga with the bendy girls in their cute little outfits, then there's the more mystical side which attracts a lot of people, then there's the plus size, which is becoming more visible," she said.
With almost two-thirds of American women either overweight or obese, according to Centers for Disease Control, and more than 15 million people practicing yoga in the United States, according to Yoga Journal, that comes as no surprise.
Kerr, who lives in Michigan, started teaching yoga 32 years ago.
"I was young and plump but not as big as I am now," she explained. "I got bigger and I needed to adapt my practice to the belly and the boobs."
She said while you don't have to be thin to do yoga, you do have to modify poses to suit the more curvaceous body. In her book Kerr demonstrates classic poses with a chair or a wall for extra support.
"Most people who are bigger can't start from a lying down position," said Kerr. "I'm 64. I do a modified headstand. I don't go all the way up."
On the plus side she said people who are bigger don't need a lot of cushioning. Kerr said the yogic practice of pranayama, or breath control, is especially good for bigger people.
"We store toxins in our fat cells, and these toxins are eliminated through the breath," she said. "It's subtle but powerful."
Jessica Matthews, of the American Council on Exercise (ACE), said practicing yoga regularly has been shown to increase muscle strength and endurance, upper and lower body strength, flexibility and balance.
But she said an ACE study found that yoga alone may not be enough for optimal fitness or weight loss.
"Yoga is not this all-inclusive thing," said Matthews. "It doesn't provide the cardio-vascular benefits."
Matthews, who is a yoga instructor at Core Yoga in San Diego, California, said she strives to create a non-competitive, non-judgmental environment in her classes. But she acknowledges that overweight people may feel vulnerable.
"In an ideal world I want to see everyone interact together," she said. "But when we hear of celebrities and Hollywood actresses doing yoga, it does attract a different crowd."
She would like to break that stereotype.
"Yoga is a place to encourage people to feel a posture, not to worry, 'When I twist is my stomach hanging over my pants?,'" she added.
Matthews said yoga can encourage overweight people to change their relationship with their bodies, and can lead to weight loss.
"Running on a treadmill might not resonate with everyone," she explained.
Kerr, too, stresses the spirit as well as flesh.
"Yoga actually enhances that self-esteem and self love because it's more meditative," she said. "You're not really tuning into your body on the Stairmaster."