Viagra, or sildenafil, is best known for treating male impotence, but it can also help with a condition called swimming-induced pulmonary edema (SIPE), which can occur when athletes or scuba divers make a sudden entry into cold water.

Researchers at Duke Center for Hyperbaric Medicine & Environmental Physiology studied 10 athletes who had experienced SIPE while exercising or competing in triathlons.

The team monitored the participants carefully as they exercised under conditions similar to those likely to trigger the SIPE response. They then compared the 10 athletes with 20 participants who had no history of SIPE. The SIPE participants then repeated the exercise after taking sildenafil. This time, the pressures were reduced.