Some people forcibly hold their breath to increase lung capacity or athletic stamina. Others, to achieve a state of light-headedness.

But playing with consciousness doesn't bode well near water, experts said. Two recent drowning deaths in the Sacramento area have been traced to submerged meditating and breathing practices .

On July 18, Sacramento yoga instructor Aaron Pappas was practicing something called the Wim Hof breathing technique. He was holding his breath and trying to hyperventilate because it relaxed him, his girlfriend Sarah Estabrook said.

When she last saw him alive, he was sitting in a pool at Asha Urban Baths with his head and shoulders above water. He lost consciousness and drowned while performing the breathing practice, she said. He died in the hospital on July 23.

Earlier this summer Yoav Timmer, 33, died while meditating face down in the Yuba River.

Rich Hanna, assistant director of parks and recreation for the city of Santa Barbara, said people who challenge themselves to breath-holding often don't realize they're in trouble until it's too late.

Hanna pushed to ban breath-holding in public pools after a young swimmer died during training a few years ago.

“They’re just kind of in this state of...euphoria or whatever," he said. "There’s some changes in their system and they don't recognize they're in danger. They basically just go unconscious in the water and pass out."

Karen Wilkinson, a yoga instructor and friend of Pappas, said he had a tendency to get extreme with his practice.

"He was always pushing the envelope, mediating for longer, trying to reach a state of consciousness that he couldn’t reach just in his daily life," she said.

"My heart breaks for Aaron, his family and friends, as well as the whole community he's contributed so much to," said Asha Urban Baths owner Cori Martinez. "My prayers are with everyone who feels the loss of his passing."

The Centers for Disease Control and Prevention recommends against what they call Dangerous Underwater Breath-holding Behavior.

The creators of the Wim Hof method urge practitioners to never try the breathing technique in or near water.

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