Investigative findings released this January determined that a man drowned while practicing a breathing meditation method that likely caused a shallow water blackout.

Danzel Goh Choon Meng went to a community swimming pool at Mimosa Park in the Yio Chu Kang area of Singapore with his wife in March, 2021.

He never came home. According to his wife, Goh had recently downloaded an app called the Wim Hof Method, a health and fitness regimen that involves three components including breathwork, cold immersion, and mindset.

She said her husband was a very fit person who exercised daily, often trying to push his limits. He had been using the Wim Hof App for about a week before his death.

On the evening of his death, Goh’s wife accompanied him to the community pool but left early to do some chores. A resident of the community entered the pool to swim laps and noticed that Goh appeared to be doing breathing exercises in the pool rather than swimming. The resident completed his own laps and left. About 15 minutes later, a neighbor walked past the pool area and saw a cellphone by the side of the pool. Recognizing it as Goh’s, his neighbor thought he had forgotten to take it home. The neighbor heard sounds coming from the phone, so he went to take a closer look and saw Goh at the bottom of the pool.

Despite resuscitation efforts, Goh was pronounced dead at the hospital.

Security camera footage showed that Goh had been submerged for close to 38 minutes.

Investigative findings were made available on January 14, 2022, and included testimony from expert witnesses.

Tan Chun Yih, an expert in the Wim Hof method, explained that as part of the breathwork component of the program, participants would take up to 30 breaths before holding their breath for a period of time. This was described as a form of meditation, where participants will gradually feel the urge to breathe build up.

Tan said that the second component of the method is cold immersion, where participants immerse themselves in cold water of between 3 degrees Celsius to 6 degrees Celsius (37 to 43 °F) for not more than two minutes.

Tan emphasized that it is critical to never practice the breathing component in water because the act of expelling carbon dioxide during hyperventilation allows the participant to lose the sensation of running out of breath, which makes it possible to hold one’s breath longer.

The consequence of holding one’s breath longer without the corresponding urge to breathe is that the practitioner may faint due to lack of oxygen.

But if he were to lose consciousness in water, he would no longer be able to consciously hold his breath and would automatically inhale again.

Tan said the Wim Hof app came with safety instructions and warnings. Before a person could start the breathwork component, a warning screen would pop up emphasizing that the practitioner should not be in or near water.

Investigators checked Goh’s phone and found that he had logged into the breathing basics part of the Wim Hof app from March 21 to March 26, 2021, in the days preceding his death.

Goh’s is not the first tragic incident to occur from practicing breathholding techniques like the Wim Hof Method while swimming.

In December 2015, there was the highly publicized case of two Navy SEALs who drowned in a training pool from shallow-water blackouts. The deaths caused changes to the military’s swimming safety protocols.

In the summer of 2017, there were two separate U.S. drowning deaths that were attributed to breath-holding meditation exercises, one of which was the Wim Hof Method.

And in June 2020, a very fit 25-year-old New Zealand man nearly drowned after blacking out while practicing the Wim Hof Method.

Fortunately, he made a full recovery despite being submerged for nearly 7 ½ minutes.

Shallow water blackout incidents are known to be more prevalent among physically fit swimmers, spear fishermen, and free divers – often to people who are described as liking to push themselves to their limits.

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

“They’re just kind of in this state of…euphoria or whatever,” Hanna 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.”