Deep divers make adaptations to make their hearts, lungs work effectively in low oxygen conditions

Scientists detected deep divers make adaptations that make their hearts and lungs work more effectively in low oxygen conditions.

Why this is important:

• The world's top free divers can hold their breath for minutes at a time, embarking on extended underwater adventures without the aid of scuba equipment.
• Two new studies led by University of Oregon human physiologist Andy Lovering identified several adaptations that might help divers keep their heart and lungs working effectively under extremely low oxygen conditions.
• The insights could lead to better treatments for lung disease.

How it works:

• In one study, the researchers placed both trained divers and healthy nondivers into a low-oxygen environment for 20 to 30 minutes.
• "The normal response to low oxygen is for arterioles in lungs to constrict," raising pulmonary blood pressure, said Tyler Kelly, a graduate student in Lovering's lab who led the work. "But we found that these athlete divers had a minimal response, if any."
• The arterioles in their lungs didn't constrict as much in response to low oxygen, reducing the strain on the heart that diminished oxygen usually causes.
• "It's a really unique adaptation," Lovering said.
• The divers were also more likely than nondivers to have a patent foramen ovale, a hole that creates a passageway between the left and right sides of the upper chambers of the heart.
• In divers, this hole could act like a relief valve, helping to reduce pressure on the right side of the heart under low-oxygen conditions.

Next steps:

• In follow-up work, Lovering wants to test whether sending ordinary people through a breath-holding diving training program can induce the same physiological changes in regular people as is seen in the divers.
• If so, structured breath-holding exercises could be a treatment for people with chronic lung disease, dampening their body's response to low oxygen and minimizing the strain on the heart and lungs.