Spirometry Has Added Value Over Electrodermal Activity as a Physiological Marker of Mental Load.

The objective distinction of different types of mental demands as well as their intensity is relevant for research and practical application but poses a challenge for established physiological methods. We investigated whether respiratory gases (oxygen uptake and carbon dioxide output) are suitable to distinguish between emotional and cognitive demands. To this end, we compared the application of spirometry with an established procedure, namely electrodermal activity (EDA). Our results indicate that electrodermal activity shows a strong responsivity to emotional stress induction, which was highly correlated with its responsivity to cognitive load. Respiratory gases were both sensitive and specific to cognitive load and had the advantage of being predictive for cognitive performance as well as self-reported emotional state. These results support the notion that respiratory gases are a valuable complement to common physiological procedures in the detection and discrimination of different mental demands.

Mitochondria-targeted antioxidant supplementation improves 8 km time trial performance in middle-aged trained male cyclists

Background Exercise increases skeletal muscle reactive oxygen species (ROS) production, which may contribute to the onset of muscular fatigue and impair athletic performance. Mitochondria-targeted antioxidants such as MitoQ, which contains a ubiquinone moiety and is targeted to mitochondria through the addition of a lipophilic triphenylphosphonium cation, are becoming popular amongst active individuals as they are designed to accumulate within mitochondria and may provide targeted protection against exercise-induced oxidative stress. However, the effect of MitoQ supplementation on cycling performance is currently unknown. Here, we investigate whether MitoQ supplementation can improve cycling performance measured as time to complete an 8 km time trial. Method In a randomized, double-blind, placebo-controlled crossover study, 19 middle-aged (age: 44 ± 4 years) recreationally trained (VO2peak: 58.5 ± 6.2 ml·kg− 1·min− 1, distance cycled per week during 6 months prior to study enrollment: 158.3 ± 58.4 km) male cyclists completed 45 min cycling at 70% VO2peak followed by an 8 km time trial after 28 days of supplementation with MitoQ (20 mg·day− 1) and a placebo. Free F2-isoprostanes were measured in plasma samples collected at rest, after 45 min cycling at 70% VO2peak and after completion of the time trial. Respiratory gases and measures of rating of perceived exertion (RPE) were also collected. Results Mean completion time for the time trial was 1.3% faster with MitoQ (12.91 ± 0.94 min) compared to placebo (13.09 ± 0.95 min, p = 0.04, 95% CI [0.05, 2.64], d = 0.2). There was no difference in RPE during the time trial between conditions (p = 0.82) despite there being a 4.4% increase in average power output during the time trial following MitoQ supplementation compared to placebo (placebo; 270 ± 51 W, MitoQ; 280 ± 53 W, p = 0.04, 95% CI [0.49, 8.22], d = 0.2). Plasma F2-isoprostanes were lower on completion of the time trial following MitoQ supplementation (35.89 ± 13.6 pg·ml− 1) compared to placebo (44.7 ± 16.9 pg·ml− 1p = 0.03). Conclusion These data suggest that MitoQ supplementation may be an effective nutritional strategy to attenuate exercise-induced increases in oxidative damage to lipids and improve cycling performance.

MATHEMATICAL MODEL FOR THE INVESTIGATION OF HYPOXIC STATES IN THE HEART MUSCLE AT VIRAL DAMAGE

The main complications of organism damaged by SARS-CoV-2 virus are various cardiovascular system lesions. As a result, the secondary tissue hypoxia is developed and it is relevant to search the means for hypoxic state alleviation. Mathematical modeling of this process, followed by the imitation of hypoxic states development, and subsequent correction of hypoxia at this model may be one of the directions for investigations. Aim. The purpose of this study was to construct mathematical models of functional respiratory and blood circulatory systems to simulate the partial occlusion of blood vessels during viral infection lesions and pharmacological correction of resulting hypoxic state. Methods. Methods of mathematical modeling and dynamic programming were used. Transport and mass exchange of respiratory gases in organism, partial occlusion of blood vessels and influence of antihypoxant were described by the systems of ordinary nonlinear differential equations. Results. Mathematical model of functional respiratory system was developed to simulate pharmacological correction of hypoxic states caused by the complications in courses of viral infection lesions. The model was based on the theory of functional systems by P. K. Anokhin and the assumption about the main function of respiratory system. The interactions and interrelations of individual functional systems in organism were assumed. Constituent parts of our model were the models of transport and mass exchange of respiratory gases in organism, selforganization of respiratory and blood circulatory systems, partial occlusion of blood vessels and the transport of pharmacological substance. Conclusions. The series of computational experiments for averaged person organism demonstrated the possibility of tissue hypoxia compensation using pharmacological substance with vasodilating effect, and in the case of individual data array, it may be useful for the development of strategy and tactics for individual patient medical treatment.

Рeculiarities of respiratory indicators in naval specialists with signs of professional burnout

Introduction.A decrease in ventilation capacity entails a significant change in the kinetics of respiratory gases, which can lead to the formation of hypoxic, hypo- or hypercapnic states, which sharply limit the adaptive capabilities of the body and facilitate the formation of professional burnout syndrome, which predetermines the relevance of their study.Purpose: to assess respiratory performance in naval professionals who have (or do not) show signs of professional burnout.Materials and methods.The study involved 250 naval specialists aged 25 to 45 years, divided into 2 groups — with the absence (group 1 (n=91 people)) and the presence (group 2 (n=159 people)) signs of professional burnout, in which respiratory indicators.Results and its discussion. It was found that naval specialists with signs of professional burnout, as compared to those who do not have it, have significantly higher indicators for peak volumetric velocity, instantaneous and average volumetric vital capacity velocity, reserve expiratory volume, as well as assessing the ratio of reserve inhalation to exhalation volume; at the same time, such persons had a significantly lower index of the reserve inspiratory volume.Conclusion. It is advisable to take into account the indicators of the functioning of the respiratory system, which is of decisive importance in providing the body with oxygen, which ultimately determines the success of adaptation and the prevention of the occurrence of unacceptable functional states, which include professional burnout.

AUTOMATED WORKPLACES FOR FUNCTIONAL DIAGNOSTICS OF ATHLETES

One of the most important tasks in modern sport's training for the sport of highest achievements is the ability to control the state of the athlete's body in the process of training and competitive activities. For this purpose, the use of systems registering and analyzing information about the functional capabilities of an athlete in the dynamics of his activity, allows you to provide an individual approach when planning and correcting training loads. This is especially important for medical and pedagogical examination. The development of methods and means for increasing physical performance and, in particular, in the practice of high-performance sports, is one of the most important principles of modern sports medicine, physiology of labor and sports. In the practice of modern sports medicine, when carrying out mass examinations of athletes, the approach based on the proposed A.Z. Kolchinskaya concept on the regulation of the body's oxygen regimes, which allows to give a general characteristic of gas homeostasis, to diagnose the main syndromes associated with disorders of the transport of respiratory gases in the body, to assess the functional state of the body at all stages of the annual cycle of sports training and during the post-exercise recovery period. Since this work is associated with a large number of calculations and subsequent processing of the information received, it is necessary to use modern means of modern information support. Thus, the automated information system (AIS) for the functional diagnostics of athletes allows many times to speed up the processing of data obtained during the examination of athletes, centrally accumulate information for its preprocessing, storage and collective use of the AIS, is equipped with convenient services for graphical and tabular presentation of data, allows analyzing the dynamics of functional the state of athletes in the annual cycle of their training, as well as at the stage of the 4-year training Olympic cycle.

Climate variability and parent nesting strategies influence gas exchange across avian eggshells

Embryo survival in birds depends on a controlled transfer of water vapour and respiratory gases through the eggshell, and this exchange is critically sensitive to the surrounding physical environment. As birds breed in most terrestrial habitats worldwide, we proposed that variation in eggshell conductance has evolved to optimize embryonic development under different breeding conditions. This is the first study to take a broad-scale macro-ecological view of avian eggshell conductance, encompassing all key avian taxonomic groups, to assess how life history and climate influence the evolution of this trait. Using whole eggs spanning a wide phylogenetic diversity of birds, we determine that body mass, temperature seasonality and whether both parents attend the nest are the main determinants of eggshell conductance. Birds breeding at high latitudes, where seasonal temperature fluctuations are greatest, will benefit from lower eggshell conductance to combat temporary periods of suspended embryo growth and prevent dehydration during prolonged incubation. The nest microclimate is more consistent in species where parents take turns incubating their clutch, resulting in lower eggshell conductance. This study highlights the remarkable functional qualities of eggshells and their importance for embryo survival in extreme climates.

Assessing post-exercise respiratory gas kinetics in clinical sample - a pilot study

Funding Acknowledgements Type of funding sources: None. Background Cardiopulmonary exercise testing (CPX) is established in the evaluation of patients with cardiac and pulmonary diseases, and its clinical utility seems to be expanding. Currently the most important diagnostic and prognostic ventilatory metrics of CPX rely on the exercise phase. Nevertheless, a consistent body of evidence suggests that important information can be derived from the recovery phase, especially in the first few minutes after exercise. In this context, patients with heart failure (HF) demonstrate a slower recovery of the oxygen consumption (VO2) compared with healthy individuals. Purpose: To comprehensively investigate the behavior of respiratory gases during recovery from CPX in a diverse cohort of HF patients. Methods: All individuals who performed CPX at the department of cardiology of Stanford University Hospital were eligible for the study. Patients were included in the experimental group if they (i) were recorded for five minutes after the exercise phase of CPX and (ii) had documented heart failure. They were excluded if they had other clinical diagnoses which may be responsible for exercise intolerance or symptoms or were unable to give informed consent. Healthy controls were recruited from the local community and were included if they did not have documented or suspected disease. Respiratory gases were collected on a breath-by-breath basis and analysed after applying a 30 second rolling average filter. Metrics were analyzed as absolute values, percentage change from peak and the half-time of recovery (T ½; i.e. the duration until a metric had returned to ½ of its value at peak). Data was analyzed over time within patients and averages between groups using parametric statistical methods. In accordance with previous studies, the amount of change in a metric after exercise is presented as the "magnitude" of overshoot. Results: 32 patients with HF (11 Female, 47 ± 13 yrs) and 30 healthy subjects (14 Female, 43 ± 12 yrs) were included. A comparison of ventilatory metrics during recovery between HF and controls is depicted in Figure 1. Peak VO2 was 1135 ± 419 mL/min (13.5 ± 3.8 mL/Kg/min) vs 2408 ± 787 mL/min (32.5 ± 9.0 mL/Kg/min); P <0.01. A significant difference between patients with HF and healthy subjects was found in T ½ of VO2 (111.3 ± 51.0s vs 58.0 ± 13.2s, p < 0.01) and VCO2 (132.0 ± 38.8s vs 74.3 ± 21.1s, p < 0.01). The magnitude of the overshoot was also found to be significantly reduced in patients with HF for VE/VO2 (41.9 ± 29.1% vs 62.1 ± 17.7%, P < 0.01), RQ (25.0 ± 13.6% vs 38.7 ± 15.1%, p < 0.01) and PETO2 (7.2 ± 3.3% vs 10.1 ± 4.6%, p < 0.01). Finally, the magnitude of the RQ overshoot showed a moderate correlation with peak VO2 (ϱ=0.58, p < 0.01). Conclusions: We observed that ventilatory kinetics measured in early recovery after CPX differ significantly between healthy subjects and patients with HF. The assessment of post exercise respiratory gases in a clinical setting may add to the prognostic and diagnostic value of CPX in heart failure. Abstract Figure.

MATHEMATICAL MODEL FOR SELECTING RESPIRATORY MODES FOR ARTIFICIAL VENTILATION OF THE LUNGS

COVID-19 mainly affects the lower respiratory tract, and in 20 % of people infected with the SARS-CoV-2 virus, it penetrates deep into the lungs. At the same time, the patient's condition quickly becomes critical, and the most severe patients must be urgently placed in the intensive care unit and connected to artificial lung ventilation (IVL) devices. Artificial ventilation is necessary when the lungs can no longer breathe in enough oxygen and breathe out the carbon dioxide that has been collected in them. In this case, ventilators take over the functions of the respiratory system. The methods of carrying out artificial ventilation of the lungs require not only experimental, but also theoretical justification. For the study, it is proposed to apply a mathematical model of the functional respiratory system, in which the breathing process is represented as a controlled dynamic system and which allows predicting the gas exchange process in the lung structures in the dynamics of the respiratory cycle under various disturbing influences. To expand the area of applicability, the process features characteristic of the conditions under consideration are taken into account. It is proposed to supplement the model with equations that take into account the elasticity and resistance of pulmonary structures. Since the possibility of obtaining quantitative and qualitative characteristics of the process of mass transfer of gases with various types of artificial ventilation of the lungs is essential, equations are proposed to describe different types of pulmonary respiration. Implementation of the proposed model will allow obtaining results on the study of the process of dynamics of respiratory gases during artificial ventilation of the lungs, contributing to the solution of practical problems on the optimization of the parameters of technical devices for artificial ventilation. The subsequent combination of the proposed model with the model of the development of a viral disease can, in the presence of an array of individual data, be of significant assistance in choosing mechanical ventilation modes in a complicated course of a viral disease.

High-Intensity Interval Exercise Performance and Short-Term Metabolic Responses to Overnight-Fasted Acute-Partial Sleep Deprivation

People practicing high-intensity interval exercise (HIIE) fasted during the morning hours under a lack of sleep. Such a habit may jeopardize the health benefits related to HIIE and adequate sleep. Fifteen habitually good sleeper males (age 31.1 ± 5.3 SD year) completed on a treadmill two isocaloric (500 kcal) HIIE sessions (3:2 min work:rest) averaged at 70% VO2reserve after 9–9.5 h of reference sleep exercise (RSE) and after 3–3.5 h of acute-partial sleep deprivation exercise (SSE). Diet and sleep patterns were controlled both 1 week prior and 2 days leading up to RSE and SSE. HIIE related performance and substrate utilization data were obtained from the continuous analysis of respiratory gases. Data were analyzed using repeated measures ANOVA with the baseline maximum oxygen uptake (VO2max) and body fat percentage (BF%) as covariates at p < 0.05. No difference was observed in VO2max, time to complete the HIIE, VE, RER, CHO%, and FAT% utilization during the experimental conditions. Whether attaining an adequate amount of sleep or not, the fasted HIIE performance and metabolism were not affected. We propose to practice the fasted HIIE under adequate sleep to receive the pleiotropic beneficial effects of sleep to the human body.