Increased heart rate and blood pressure, the invariable accompaniments of physical exercise, are also characteristic of acute anxiety. In the latter, however, these changes are rarely pleasurable. No book on acute anxiety has competed with Running for a best-seller status. Moreover, no cardiac benefits, ascribed to the hemodynamic aspects of exercise, have been claimed for anxiety. Even the mechanism of the tachycardia of anxiety differs from that of exercise. In the latter, vagal withdrawal may play a greater part than sympathetic overactivity. 1 β-Adrenergic blocking agents, which reduce the heart rate in emotional stress, are generally ineffective in exercise. The usefulness of β-adrenergic blocking drugs, particularly oxprenolol hydrochloride, has been demonstrated in a number of acutely stressful activities, such as public speaking, driving in heavy traffic, race-car driving, or landing an airplane. Monitored heart rates and, whenever practicable, blood pressures showed a substantial increase during these activities. Oxprenolol hydrochloride in