Objectives: The purpose of the study was to estimate training energy expenditure (TEE) and daily energy expenditure (DEE) in the Polish elite athletes engaged in endurance sports and power sports, and to compare their levels with the Polish energy intake standards. Material and Methods: The study sample consisted of 30 athletes (15 women and 15 men) whose energy expenditure was estimated based on heart rate monitoring. Results: The mean values of DEE obtained for women engaged in endurance sports (WE – women endurance) and power sports (WP – women power) were 3201±533 kcal and 3217±554 kcal, respectively. In the group of male athletes, the respective values were 4518±717 kcal for endurance athletes (ME – men endurance) and 4459±837 kcal for power athletes (MP – men power). The mean values of TEE for female athletes were 819±240 kcal (WE) and 1047±248 kcal (WP). Those obtained for male athletes were significantly higher: 1440±675 kcal (ME) and 1337±331 kcal (MP). Conclusions: Unlike the demands of particular sport disciplines, an athlete’s sex proved to be a factor causing significant differences between the TEE and DEE of athletes representing different sport disciplines. Individual athletes were found to differ significantly in their demand for energy, which in some cases was considerably different from what energy intake standards propose. Int J Occup Med Environ Health. 2019;32(1):1–13