[Purpose] Occlusion training with low-intensity resistance exercises and blood flow restriction increases muscle cross-sectional area and strength. This form of training is used in rehabilitation; therefore, the aim of this study was to examine the effect of one occlusion training session on the cardiovascular response to bouts of exercise. [Subjects and Methods] Two groups took part: a control group without blood flow restriction and an experimental group with blood flow restriction. A single training session was used with the exercise intensity set at 40% of the one repetition maximum. Maximum voluntary contraction, arterial blood pressure, and electrocardiogram measurements were performed. [Results] Heart rate was slightly higher in the control group. The performed training had no effect on diastolic blood pressure in either group, however, a tendency for a small systolic blood pressure increase was observed during the session in the experimental group. JT interval changes did not reveal significant differences between groups. There were no significant changes in ST-segment depression during the exercise or at rest. A lower tendency for JT/RR increases was observed during the repeated exercise tasks with partial blood flow restriction. [Conclusion] Low intensity exercises carried out with a partial blood flow restriction do not result in significant overload of cardiac function.

Background: Endogenous triggers such as voluntary breath-holding induce various cardiovascular responses typically including modification of blood CO 2. During dynamic exercise these responses may have a negative impact on performance or may associate with cardiovascular risk subjects. Therefore, we hypothesized that voluntary breathing tests induce changes in cardiovascular (CV) oxygenation that lead to cardiovascular-functional changes, measured by a complex of integrated cardiovascular parameters and their interactions. So the aim of the study was to determine the impact of the voluntary breath-holding on changes and interplay of cardiac and peripheral parameters. Method: 18 girls (average age: 23.4 ± 1.3 years) performed 2 voluntary breath-holdings to failure, with a 5 min rest. Cardiac functional parameters were recorded using the electrocardiogram (ECG) analysis system "Kaunas-load". The blood flow in the calf was determined by venous occlusion plethysmography. Near-infrared spectroscopy (NIRS) was used for non-invasive monitoring of oxygen saturation in tissues (StO 2). Results: Throughout the first breath-holding, heart rate (HR) increased from 89.5 ± 3.9 bpm to 107.6 ± 4.2 bpm (P<0.05). The ECG JT interval decreased at the onset of breath-holdings, the intervals ratio (JT/RR) increased (P<0.05), and the ST-segment depression was not altered significantly. Arterial blood flow (ABF) was reduced from 3.5 ± 0.47 mL/100 mL/min to 1.64 ± 0.38 mL/100 mL/min (P<0.05) at the end of the first breath-holding. The StO 2 of the calf muscles decreased during both breath-holdings. Within 60 s of recovery time, StO 2 exceeded baseline 9.5% (P<0.05). Conclusion: Breath-holding impact changes in the systemic (central) circulation and caused significant peripheral changes, i.e., decrease in arterial blood flow and oxygen saturation. The most essential alteration occurred between the HR and arterial blood pressure (ABP) parameters. The strongest interaction observed between HR and ABP, and in calf muscles-between ABF and StO 2 .

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.

Abstract. The aim of this study was to complement an analytical approach by new methodology of data sequences analysis of muscular and cardiovascular indices

Blood flow restriction late in recovery after a heavy resistance exercise bout decreased muscle oxygenation and work capacity during the subsequent heavy resistance exercise bout.