Effect of endurance physical training on cardio-respiratory system reactive features (mechanisms of training load...

The results of a series of experiments carried out under heavy physical loads during the training of 96 elite cyclists, rowers and swimmers were based on the following: (1) complex analysis of dynamics of sensitivity, stability and speed of responses of cardio-respiratory system (CRS) to hypoxia, CO2-H+ ionic irritants; (2) neurogenic (working) response stimuli; (3) range of changes in ventilatory, circulatory and metabolic responses and their dynamic characteristics. It was demonstrated that sensitivity, stability and speed of responses to shifts in respiratory homeostasis changed during each physical load and in the process of training. The nature and the extent of changes are connected with the intensity of the load as well as its type and duration. After training, we observed changes in the sensitivity, stability and response speed of CRS to shifts in respiratory homeostasis; we also noted that the total reactivity changes revealed the same direction of change as the above mentioned CRS physiological reactivity parameters. It was also observed that the dynamics of reactivity changes to hypoxia, CO2-H+ irritants and neurogenic CRS response are connected to the dynamics of peak of CRS response to physical load and to its stability and response speed. These results indicate the existence of certain mechanisms which regulate the setting up of the functional capacity in athletes.