Changes Related to Fatigue in Cardiorespiratory Response Sensitivity to Hypoxic and Hypercapnic Stimulation during Strenuous Physical Load

Abstract

Background: The aim was to study changes in the sensitivity of CRS responses of skilled athletes caused by fatigue during a strenuous physical load. Material/Methods: Response sensitivity to hypoxic and hypercapnic stimuli was analyzed in a group of high performance rowers (n=12) aged 18-22 years during exercising on "Concept-II" rowing ergometer. Two types of loads were used: sustained intensive load at high oxygen consumption (78-83% of VO 2max) and relatively easier load (49-62% of VO 2max) performed within 5 minutes. The method of rebreathing was used to determine responses sensitivity to СО 2. Results: The results showed an increase in respiratory response sensitivity to hypoxia and a decrease in sensitivity to acidosis stimulus of respiration (СО 2-Н +) at the end of a strenuous load in presence of fatigue. Ventilatory response to hypoxic stimulus increased reliably before the end of work. At high intensity of loads during increment hypercapnia even in highly trained athletes the inhibition of ventilatory response has been noted Conclusions: The data provide additional grounds for correction of fatigue by means of regulating the character and the intensity of physical loads in the process of endurance training. It has been shown that changes in sensitivity of CRS responses and other aspects of reactive features are of importance for special work capacity manifestations.

Stimulating Aerobic Energy Supply Reactions of Athletes in Rugby Union

“…Increasing the speed of development of the cardiorespiratory system creates conditions for achieving peak reaction values, increases the share of economical aerobic energy supply in the overall energy balance to support performance of athletes (Rovniy et al, 2017;Diachenko, et al, 2020;Tyshchenko et al, 2020). An increase in the kinetics of reactions of the cardiorespiratory system is one of the objective indicators of a positive change in the function of aerobic energy supply as a response to special loads (Mishchenko et al, 2009;Sado et al, 2023). The use of conditions for the implementation of these reaction stimuli allows the development of functions of the cardiorespiratory system with anaerobic glycolytic energy supply not been actively used in the work, which is a requirement for improvement of aerobic capabilities of athletes.…”

Adaptation to Intense Muscular Activity and Peculiarities of Autonomic Regulation of Heart Rate Variability in Athletes (Ii Message)

“…The unsatisfactory adaptation of the human body to environmental factors is characterised by a pronounced vagotonic and pronounced sympathicotonic types of HR regulation in a state of relative rest. [3,6,20].…”

“…Додатково оцінюються і межі рівнів функціонування (граничні можливості) систем, що лімітують певний вид спортивної діяльності [5,6,20]. Аналiз та оцiнка перiодичних компонентiв СР здiйснювалася шляхом дослiдження спектральних показникiв у трьох дiапазонах [1,6,15,17,23]: HFav -дисперсiя дихальних хвиль (спектральна потужнiсть) з частотою 0,15 -0,4 Гц, LFav -дисперсiя повiльних хвиль 1-го порядку (частота 0,04-0,15 Гц), VLFav -дисперсiя повiльних хвиль 2-го порядку (частота 0,003-0,04 Гц), а також TP -загальна дисперсiя СР (частота 0,003-0,4 Гц).…”

Реалізація Функціонального Потенціалу Й Особливості Прояву Спеціальної Працездатності Кваліфікованих Спортсменів У Циклічних Видах Спорту

“…Висновки. За результатами виконання тестових навантажень у лабораторних умовах, що дозволяють визначити аеробні та анаеробні [5,10,24,26] . При этом наиболее важное значение имеет специфичность факторов ограничения специальной работоспособности спортсменов, уровня развития физических качеств при их специфическом сочетании для конкретной соревновательной дистанции [6-8, 22, 24] .…”