Even veteran divers can be felled by the bends, painful nitrogen bubbles that form in the blood and tissues when pressure drops rapidly. Zeljko Dujic, a physiologist at the University of Split School of Medicine in Croatia, says the secret to avoiding this decompression sickness could be vigorous exercise.
Dujic and his colleagues subjected 12 divers to an intense 40-minute workout on a treadmill. Twenty-four hours later, the divers sat in a pressure chamber simulating conditions 60 feet underwater. After 80 minutes, the chamber pressure quickly returned to surface levels. Echocardiograms showed one-fourth as many nitrogen bubbles in their hearts compared with readings in similar tests that were not preceded by heavy workouts. Dujic theorizes that nitric oxide in the body, produced during exercise, destroys most of the tiny“bubble nuclei” around which larger bubbles form. He is not yet prepared to recommend exercise in place of other methods of dealing with the bends. But there seems no harm in working out a day before you slip into a wet suit.