Role of Power and Frequency Characteristics of the Cardiorespiratory System in Conditions of Minimal Physical Exercise

Abstract

It is our point of view that it is necessary to study in more detail and consistently the dynamics of joint reactions of respiration and blood circulation during physical load. The study aims to determine which component of the cardiorespiratory system is a more labile parameter in forming the body's adaptive reactions in minimal physical loads. The objectives of the study are to reveal the role of respiratory and cardiovascular components of the cardiorespiratory system in achieving the overall useful result during bicycle ergometry exercises of minimal power and to make a comparison of expressiveness changes in respiratory amplitude and its rate as well as to carry out comparing human cardiorespiratory system activity and the one in animals. Healthy young people of both sexes were examined. They were provided with standard stages of short-term physical exercise load ranging from negligible to moderate. A bicycle ergometer with a pedaling rhythm of 40 per minute was used to ensure this. Before loading, at its peak, and after it, spirography, pulsometry, and tonometry were performed. These parameters were obtained for each subject simultaneously. The principles of forming cardiorespiratory interaction, revealed in the given study in humans, corresponded with the parameters of baro - and chemoreflex obtained by us earlier in acute experiments on cats. The statistical analysis was carried out using Statistica ® 7.0 package (StatSoft Inc., USA). The results' significance was assessed using Student's t-test and sign test. At minimal physical exercises, pulmonary ventilation is performed through more pronounced changes in respiratory amplitude and less markedly through respiratory rate variations. Under given conditions, domination of the respiratory system, activity was proved to be most effective. Arterial pressure and pulse react least of all. First, the systemic blood pressure increases, and the changes in cardiac frequency activity are realized last. In such cases, this parameter even can remain unchanged. The principles that define the different intensities of cardiorespiratory system components' activity for human organisms and animals turn out to be similar.