Interaction between Cardiac Functional Indices during Incremental Exercise Test Reveals the Peculiarities of Adaptation to Exercising

Abstract

Background and objectives: Physical load causes structural changes in the heart that vary depending on the type of training and may affect the function of the heart. Aim of the study: To determine, using the applied co-integration method on algebraic data, the impact of sprinting and of endurance adaptation on the dynamic interactions of cardiovascular functional indices while participants were performing under an increasing workload, up to their inability to continue. Materials and Methods: Healthy athletes were chosen to take part in this study and were separated into two groups: Sprinters (n = 11) and endurance athletes (n = 13). The bicycle ergometric method of incremental increase in a provocative workload (graded stress) was used. The heart rate, stroke volume, and cardiac output were determined using the tetrapolar rheography method. Results: Individuals who are adapted to endurance while carrying physical loads, in contrast to well adapted sprinters, are characterized with a lower rate of changing the pace of interactions between stroke volume and cardiac output while performing at an increasing workload up to their inability to continue. Also, endurance athletes displayed a long and relatively stable phase as well as a greater decrease of interaction between indices at the end of the workload. At the beginning of the exercise, the interaction between the stroke volume and the cardiac output was reduced. However, as the physical load continued, this interaction became significantly stronger. The comparison of the stroke volume and the cardiac output’s dynamic interaction revealed that the endurance group had a greater working capacity. Conclusions: Typical dynamics of interactions during the testing with an increasing physical load can be differentiated into separate phases: The decrease of interaction at the onset of the load, the increase during the continuation of an increased workload, and the decrease at the last stages of the load.

Extended approach to sum of absolute differences method for improved identification of periods in biomedical time series

“…The value for the first zero-point can remove simple measurement errors when data are recorded once every few seconds. The value for the second zero-point corresponds well with what is known about physiological response of heart to changing load [9] .…”

“…Second zero-point of jerk corresponds to 16–24 s window for moving average. In that range physiological effect should already be visible [9] .…”

“…14 using “Simultaneous physiological measurements with five devices at different cognitive and physical loads” dataset from PhysioNet database [11 , 12] the resulting window length would become 210–230 or 490–590 s respectively for each dataset using the established approach. It is not only intuitively too long, but also would mask physiological response to a change in physical exertion that becomes visible in less than a minute [9] . Beyond that point a change can still be observed, but it is then related to cardiac drift when maintaining a level of increased exertion [4] .…”

Changes in the hemodynamics of athletes under the influence of anaerobic physical tests of different duration

“…За умов виконання тестів оцінювання МСК у здорових осіб зареєстровані значення ЧСС на рівні 184-200 уд./хв УО -120-157 мл, ХОК -22-29 л/хв [14 -16]. У кваліфікованих спортсменів-стаєрів зміни показників гемодинаміки після завершення роботи до відмови були ще більшими -ХОК на рівні 30 л/хв, ЧСС -понад 170 уд./хв, УО -близько 170 мл [17]. Інші автори виявили у цих умовах величину максимального значення УО на рівні 190 мл, ЧСС -близького до 190 уд./хв [18].…”

“…Інші автори виявили у цих умовах величину максимального значення УО на рівні 190 мл, ЧСС -близького до 190 уд./хв [18]. Зміни гемодинаміки спортсменів-спринтерів були меншими -ХОК на рівні 17 л/хв, УО -близько 120 мл [17] Для вивчення анаеробних можливостей ми використовували 30-секундний велоергометричний тест Уінгейта в модифікації O. Inbar [19], величина навантаження становила 3,5 Вт/кг [20]. Перед початком тесту виконували розминку (5 хв, 1,5 Вт/кг).…”