INTRODUCTION

This study examines the acute effect of heart rate variability (HRV) biofeedback on anxiety and relaxation states.Eighteen healthy males exposed to work-related stress were randomized into an HRV biofeedback group (BIO) or comparative group (COM). The device used by the COM group appeared identical to the HRV biofeedback device, however, it did not provide biofeedback, rather it displayed a wave which the subjects were instructed to observe.