The present study should give some indication as to whether the audio-visual relaxation system has a stress-relieving effect. The objective of this bachelor thesis was to measure the stress index of the participants using heart rate variability (HRV). Significant correlation between the variables of the participants’ subjective experience and the HRV parameter showed a link between the physiological and psychological data, meaning improved concentration levels and performance levels during working hours. Overall, the results of the study confirm the proposition that breaks during working hours should be put to good use to gain new energy and strength. This means that an increased level of performance can be expected after breaks.