The concept of biological age as an assessment of the aging rate of the human body is given. The review of two methods for determining biological age - bicycle ergometric and entropic - is presented. The data on workers of three industrial enterprises of the Urals region employed in harmful labor conditions were used in the present study. A total of 197 male workers were surveyed. The age range of the surveyed workers was 30...60 years; the average age was 46,9 years. All participants in the study performed ultrasound examination of the heart, capnography and veloergometry. Heart rate, arterial systolic and diastolic pressure, height and weight were measured. The aging rate and biological age were calculated on the basis of these physiological parameters by special techniques. The results of a comparison of biological age determined by two different methods are given. The categories of male employed in harmful working conditions who are most vulnerable from the point of view of adaptation to the environmental factors are identified. These are those with the highest relative mass of the heart (LVMI>132 g/m 2 ), as well as individuals who cannot reach high loads (groups with FF1=600 kgm/min and FF1=750 kgm/ min). In these groups of workers, the differences between the mean values of biological age, calculated with the help of different approaches, are minimal, the biological age itself exceeds the KV (on average), which indicates an accelerated aging, respectively, of less adaptability to environmental factors. It is shown that the biological age values determined with the help of different approaches cannot always be equal to one another for one person.