from http://www.allure.com/magazine/2007/...xiety_Exercise

Antianxiety Exercise
By Lois B. Morris

Doctors have known that aerobic conditioning can ease the symptoms of panic attacks almost as well as medication, but researchers in Germany have found that a single half hour of moderate exercise can also be effective. Psychiatrist Andreas Ströhle, at the Charité-University Medicine Berlin, asked one group to walk on a treadmill for 30 minutes at medium intensity and the other to rest in bed. Afterward, all received a drug (CCK-4) known to trigger panic in most people. The resting group had twice the rate of subsequent panic attacks than did those who had exercised. Further research on sufferers of severe anxiety is needed to determine how frequently and intensely they need to exercise in order to see benefits.