Objective of the present study was to determine the coordination in the respiratory and circulatory systems of children of different ages and sports qualifications. Methods and structure of the study. Subject to the study were the 9-17 year-old female rhythmic gymnasts. The subjects had different sports qualifications – from II adult category to Master of Sport. The following parameters were measured: vital capacity – using the spirograph "Spiros-100"; blood pressure – using a tacho-oscillographic method; pulse rate – using the device "Varikard" software-hardware complex ("RAMENA", Russia). The rates were obtained at rest and after a three-minute standard workout complex applied in gymnastics. Results and conclusions. The detected reciprocal reactions of the respiratory and circulatory systems to physical loads indicated a significant role of respiration in the economization of the functions of the cardiovascular system of female gymnasts. It is advisable to include in the young gymnasts training process exercises aimed to increase the vital capacity and respiratory organs functioning, which will accelerate the process of recovery after physical exercise, which will, in turn, contribute to the improvement of sports skills. © 2021, Teoriya i praktika fizicheskoy kul'tury i sporta. All rights reserved.