Peak Performance

Evolution 1204

Sildenafil, the generic name for

Viagra, is rising to new heights-and skiers who suffer from altitude sickness might soon feel the results. Curious about the anti-impotence drug's influence on physical exertion, German scientists tested its effects on 14 healthy Swiss and German climbers as they scaled Mount Everest. Sildenafil rose to the occasion: According to results published in the August 2004 Annals of Internal Medicine, sildenafil reduced pressure on the blood vessels in the lungs and increased maximum aerobic capacity while the mountain climbers were high up on the 29,035-foot Himalayan peak, where oxygen is in short supply.

As it turns out, sildenafil's effects imitate the oxygen-rich blood flow of the Tibetans, which has evolved naturally during their 20,000 years on the high Tibetan Plateau, says Cynthia Beall, Ph.D., co-director of The Center for Research on Tibet at Case Western Reserve University. While the results from Mount Everest are only preliminary, scientists say sildenafil might eventually reduce ill effects of physical activity at high elevation. In other words, the drug might help skiers breathe easier-or at least battle that vacation-wrecking altitude sickness.