The research was conducted by a member of the 60th Russian Antarctic Expedition at the all-yearround Mirny Station. The purpose was to study the effect of changed patterns of tobacco smoking on the adaptive capabilities of polar station staff. Materials and methods. Adaptive capabilities were evaluated using the method of cardio-respiratory synchronism, assessing the index of regulatory and adaptive status (IRAS). It is based on recording the synchronization parameters of controlled high respiratory rate and heart rate. IRAS dynamics was compared in four subjects (three regular smokers and one non-smoker as a control) over the course of one year of wintering. The subjects had comparable anthropometric data, health status and working conditions at the station. They were exposed to a similar amount of adverse environmental factors due to their professional activities and lived according to the station’s standard schedule without any personalized changes in their day regimen. Smoking patterns were determined by independent decisions of each expedition member and by the size of personal stocks of tobacco products prepared for the wintering. Results. In polar expedition members faced with smoking cessation or inability to adequately meet this need, IRAS decrease, being a marker of human adaptive capabilities, allowed us to determine the relationship between pronounced changes in the dynamics of regular tobacco smoking and body’s adaptive capabilities. The authors assume that organizational arrangements (sufficient stocks of nicotine-containing products such as cigarettes and tobacco) at the station as well as educational activities (dissuading expedition members from abrupt non-supervised changes in their smoking patterns during Antarctic wintering and properly explaining the reasons why such actions are undesirable) may contribute to improving the health of expedition members and optimizing their living conditions at the polar station. Completing a smoking cessation programme with medical supervision in advance (while preparing for a polar expedition) as well as upon returning from the station (at the end of the adaptation period) can be recommended.