The invention relates to a method for determining the physical and/or psychological state of a subject. The heart rate variability (HRV) of the subject is analyzed in the time domain, wherein at least one frequency distribution of interbeat intervals (IBI) which are detected in at least one examination time period (1) is examined in the analysis. In order to obtain particularly significant and quickly interpretable information for this purpose, the frequency distribution is examined for a multimodal distribution.