Oxycon Pro Research Articles

Cardiac repolarisation indices are associated with oxygen consumption during maximal exercise test in highly-trained cross-country skiers

ABSTRACT The objective of this study was to test the vectorelectrocardiographic T-wave characteristics for their associations with oxygen consumption (VO2) and physical performance during a maximal cardiopulmonary exercise test (CPET) in highly trained cross-country skiers. Male highly trained cross-country skiers (n = 30) performed the maximal CPET on the bicycle ergospirometric “Oxycon Pro” system with simultaneous oxygen consumption (VO2) and electrocardiogram recording. The measurements were done at rest; the stage preceding anaerobic threshold (preAnT); peak load; and recovery. The anaerobic threshold was estimated by respiratory exchange ratio. Physical performance was estimated by maximal oxygen consumption (VO2max/kg). VECG characteristics were calculated using Kors transformation procedure. During the test, the magnitudes of T-vector, Tx and Ty components decreased until preAnT, then stayed relatively stable until peak load, and reversed during recovery. In univariate linear regression analysis, T-vector amplitude and Tx, Ty and Tz magnitudes were associated with VO2/kg during the test (p < 0.010). The baseline T-vector characteristics were not associated with physical performance. At the preAnT stage, Tx and T-vector amplitude were associated with VO2max/kg (RC 12.70, 95% CI 0.68–24.73, p = 0.039 and RC 10.64, 95% CI 1.62–19.67, p = 0.023, respectively).

Response of cardiorespiratory system during maximal exercise cycle ergometer test in women cross-country skiers with different skills levels

Objective: to estimate the functional features of the cardiorespiratory system of female cross-country skiers with different skills levels at the maximal bicycle ergometer test.Material and methods: 70 female cross-country skiers were divided into three groups. The first group included 21 cross-country skiers with first adult sporting rank, the second — 25 candidates in master of sports, the third group — 24 sport masters in cross-country skiing. Maximal exercise tests were used to determine cardiorespiratory fitness via spiroergometric system «Oxycon Pro» (Jaeger, Hoechberg, Germany).Results: The most notable differences were observed between the first-class and the masters of the sports groups. In the first-class group the heart rate during the maximal exercise test was, on average, 11 beats/min higher than in the master of sports group (p&lt;0.05), and the oxygen consumption at the anaerobic threshold was, on average, lower by 7.7 ml/min/kg (p &lt; 0.05) when comparing the same groups.Conclusion: The influence of skills levels on physiological parameters at maximal bicycle ergometer test was shown. The capacity in the first group occurs due to cardiovascular system tension, and the same in the group high qualification skiers happen due to the mechanisms of oxygen transport development.

Analysis of the performance of the portable Cortex Metamax 3B gas analysis system in simulated and real workouts with Vietnamese teenagers

The aim of this study was to investigate the performance of the mobile Cortex Metamax 3B (MM3B) automated gas meter in simulated and real workouts involving teenagers. A total of 28 healthy volunteers (13 men, 15 female) were selected with the following characteristics (mean ± SD): age 17.2 ± 3.1; height 167.1 ± 13.5 cm; weight 54.6 ± 10.4 kg. The following equipment were used: Hypermax 3B (breath-by-breath breathing system), Validator for Gas Exchange Systems (VGES), and Douglas-bag technique (DBT). The results have shown that MM3B is stable at the permitted range during 3 hours while monitoring the gas fractions, as well as the VE, VO2, and VCO2 created by GESV, especially at moderate and high metabolic rates (2% deviation and modest physiological significance). MM3B rated both VO2 and VCO2 significantly higher by about 10-17% at moderate and strenuous activity than DBM and at all exercise levels than Oxycon Pro, although without a significant margin of error in VE. Between the two criteria systems, none of the metabolic variables showed any discernible change (DBM and Oxycon Pro). The MM3B provided acceptable data on stability and reliability, but it was decided that without further adjustment for VO2 and VCO2, the data were not valid during moderate and strenuous activity.

Optimization of VO2 and VCO2 outputs for the calculation of resting metabolic rate using a portable indirect calorimeter.

This study aimed to compare the Cosmed K5 portable indirect calorimeter, using the mixing chamber mode and face mask, with a stationary metabolic cart when measuring the resting metabolic rate (RMR) and to derive fitting equations if discrepancies are observed. Forty-three adults (18-84 years) were assessed for their RMR for two 30-min consecutive and counterbalanced periods using a Cosmed K5 and an Oxycon Pro. Differences among devices were tested using paired sample Student's t-tests, and correlation and agreement were assessed using Pearson's correlation coefficients, intraclass correlation coefficient and Bland-Altman plots. Forward stepwise multiple linear regression models were performed to develop fitting equations for estimating differences among devices when assessing oxygen uptake (VO2 diff , mL·min-1 ) and carbon dioxide production (VCO2 diff , mL·min-1 ). Furthermore, the Oxycon Pro was tested before being confirmed as a reference device. Significant differences between devices were found in most metabolic and ventilatory parameters, including the primary outcomes of VO2 and VCO2 . These differences showed an overestimation of the Cosmed K5 in all metabolic outcomes, except for Fat, when compared to the Oxycon Pro. When derived fitting equations were applied (VO2 diff - 139.210 + 0.786 [weight, kg] + 1.761 [height, cm] - 0.941 [Cosmed K5 VO2 , mL·min-1 ]; VCO2 diff - 86.569 + 0.548 [weight, kg] + 0.915 [height, cm] - 0.728 [Cosmed K5 VCO2 , mL·min-1 ]), differences were minimized, and agreement was maximized. This study provides fitting equations which allow the use of the Cosmed K5 for reasonably optimal RMR determinations.

ADAPTATION TO INTENSE MUSCULAR ACTIVITY AND PECULIARITIES OF AUTONOMIC REGULATION OF HEART RATE VARIABILITY IN ATHLETES (II MESSAGE)

Introduction. Determining the mechanisms of regulation of the cardiovascular system as an indicator of the functional state of the body, on which the effectiveness of sports activity largely depends, remains relevant in assessing the ways of adaptation of the athlete's body to various physical activities. The purpose of the study is to investigate the peculiarities of physical performance of qualified athletes with different types of autonomic regulation of heart rate based on the mathematical analysis of heart rate variability. Material and methods. The study involved 214 skilled athletes specialising in rowing, basketball, handball, athletics, hockey, triathlon, cross-country skiing, biathlon and other sports. Methods of analysis of heart rate variability features, methods of determining physical performance of qualified athletes and the reaction of the cardiorespiratory system to test loads (ergospirometric complex "Oxycon Pro", treadmill LE-200 C), mathematical and statistical methods. Results. When performing strenuous physical activity, the initial type of autonomic regulation largely determines the effectiveness of compensatory and adaptive reactions of the organism. Thus, the normotonic and moderately vagotonic type of regulation of the HR in a state of relative rest was inherent in highly skilled athletes with a high level of functional fitness. Normotonic and vagotonic types of HR regulation characterise the optimal functional state of a sportsman's organism, high functional capabilities of the organism, which ensure the preservation of vegetative homeostasis, the optimal level of regulation efficiency and the level of functioning economy, and stable regulation. The sympathicotonic type of HR regulation is also inherent in satisfactory adaptation to strenuous physical activity and sufficient functional capabilities of the sportsman's organism. However, there are already signs of dysregulation in the central regulatory circuit, a reduced level of efficiency of HR regulation, an increased level of tension in the regulatory mechanisms of adaptation. Against this background of such regulation of HR, a deterioration of the functional state of a sportsman can be noted, objective signs of fatigue appear. Prognostically unfavourable for athletes in a state of relative rest is a pronounced vagotonic type of SR regulation, as well as a sharply expressed sympathicotonic type of SR regulation - characterising reduced functional capabilities of the organism, unsatisfactory adaptation to strenuous physical activity. Conclusions. The vagotonic, normotonic and sympathicotonic types of HR regulation in a state of relative rest allow us to speak about the satisfactory adaptation of the human body to the influence of various environmental factors. 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.

Heart rate variability in cross-country skiers with different level of maximum oxygen consumption

AIM: This research aimed to study heart rate variability (HRV) in cross-country skiers with different levels of maximal oxygen consumption (VO2max).&#x0D; MATERIALS AND METHODS: HRV analysis was carried out using the Ecosan-2007 (Medical Computer Systems, Russia) complex in 52 cross-country skiers from the Komi Republic team (candidates for master of sports and master of sports of Russia). The Oxycon Pro ergospirometric system (Erich Jaeger, Germany) was used to calculate VO2max. To identify the HRV patterns in individuals with different levels of VO2max, volunteers were divided into two groups: with VO2max up to 4400 ml/min (n=27) and over 4400 ml/min (n=25). The MannWhitney U-test was used to ascertain whether the differences between groups were statistically significant. A Spearman correlation test was used to analyze the relationship between the VO2max and HRV.&#x0D; RESULTS: Athletes with different levels of VO2max showed significant differences in several HRV indicators as follows: absolute values of LF and VLF waves, the relative value of HF waves, LF/HF, and IC indices. Correlation analysis indicated the presence of a significant negative correlation between the absolute values of VO2max and MxDMn, MxRMn, LF/HF, IC, power of LF, and LF%. VLF waves. Furthermore, a positive correlation was observed between VO2max and HF%. The relative values of the VO2max/kg showed a significant negative correlation with MxRMn, TP, LF, VLF, LF/HF, and IC; and positive with HF%.&#x0D; CONCLUSION: In cross-country skiers, a significant correlation was identified between VO2max and HRV parameters. Compared to Athletes with lower VO2max, those with higher VO2max had a more efficient mode of heart rate regulation.

Multiple propane gas burn rates procedure to determine accuracy and linearity of indirect calorimetry systems: an experimental assessment of a method.

Indirect calorimetry (IC) systems measure the fractions of expired carbon dioxide (FeCO2), and oxygen (FeO2) recorded at the mouth to estimate whole-body energy production. The fundamental principle of IC relates to the catabolism of high-energy substrates such as carbohydrates and lipids to meet the body's energy needs through the oxidative process, which are reflected in the measured oxygen uptake rates (V̇O2) and carbon dioxide production rates (V̇CO2). Accordingly, it is important to know the accuracy and validity of V̇O2and V̇CO2 measurements when estimating energy production and substrate partitioning for research and clinical purposes. Although several techniques are readily available to assess the accuracy of IC systems at a single point for V̇CO2 and V̇O2, the validity of such procedures is limited when used in testing protocols that incorporate a wide range of energy production (e.g., basal metabolic rate and maximal exercise testing). Accordingly, we built an apparatus that allowed us to manipulate propane burn rates in such a way as to assess the linearity of IC systems. This technical report aimed to assess the accuracy and linearity of three IC systems using our in-house built validation procedure. A series of trials at different propane burn rates (PBR) (i.e., 200, 300, 400, 500, and 600 mL min-1) were run on three IC systems: Sable, Moxus, and Oxycon Pro. The experimental values for V̇O2 and V̇CO2 measured on the three IC systems were compared to theoretical stoichiometry values. A linear relationship was observed between increasing PBR and measured values for V̇O2and V̇CO2 (99.6%, 99.2%, 94.8% for the Sable, Moxus, and Jaeger IC systems, respectively). In terms of system error, the Jaeger system had significantly (p < 0.001) greater V̇O2(mean difference (M) = -0.057, standard error (SE) = 0.004), and V̇CO2(M = -0.048, SE = 0.002) error compared to either the Sable (V̇O2, M = 0.044, SE = 0.004; V̇CO2, M = 0.024, SE = 0.002) or the Moxus (V̇O2, M = 0.046, SE = 0.004; V̇CO2, M = 0.025, SE = 0.002) IC systems. There were no significant differences between the Sable or Moxus IC systems. The multiple PBR approach permitted the assessment of linearity of IC systems in addition to determining the accuracy of fractions of expired gases.

Accordance of energy intake to energy expenditure in skiers across the preparation phase

In elite sport the amount of physical activity requires a professional athlete to have a stable energy balance when the energy intake (EI) is equal to energy expenditure (EE). Its maintenance provides high performance across the phases of the training cycle. The purpose of this research was to analyze the compliance of EI to EE among skiers during the preparation phase of the training cycle. Material and methods. The single-centre, prospective, longitudinal, full-design, noncontrolled study has been performed on 55 highly trained cross-country skiers (mean age 20.1±4.7 years) during the preparation phase of the training cycle. EI was estimated by a 24-hour dietary recall. EE was estimated at rest and during physical activity by indirect calorimetry using the Oxycon Pro system. Results. During the preparation phase dietary calorie intake in skiers (3191±961 kcal/ day), estimated excluding sports drink consumption during the training, was lower approximately by 40% than the reference norms for people engaged in intensive physical activity. At the same time, there was 1.3-fold excess of fats in the diet against the background of low consumption of carbohydrates. Our results showed that in 75% of athletes the measured rest energy expenditure (REE) was higher than the calculated REE by 20% and amounted to 2139±363 kcal/day. Total EE during the preparation phase, calculated by application of Physical Activity Level (PAL) coefficient equal 2.4 (according FAO/ WHO/UNU recommendations), was 5137±873 kcal/day (73.9±12.3 kcal/kg per day). In most cases registered total EE was more than 5000 kcal/day, in other words, total EE exceeded the energy value of the daily diet and thus required the increase of EI. In addition, in our study we observed an increase of carbohydrate contribution to the total EE during high-intensity exercise. Conclusion. The discrepancy between dietary calories and daily EE among the elite athletes was revealed. An imbalance between carbohydrates and fats was identified in the diet, and that did not provide the optimal expenses of macronutrients during highintensity exercise.

Состояние кардиореспираторной системы биатлонистов и лыжников-гонщиков Республики Коми при велоэргометрическом тестировании

The purpose of this paper was to compare the physiological parameters of the cardiorespiratory system at rest and during the bicycle ergometer test to exhaustion in biathletes and cross-country skiers to identify the difference in the aerobic performance of athletes of two closely related winter sports. Materials and methods: 18 biathletes and 28 male cross-country skiers aged 17–21 years, all with the rank of the Candidate for Master of Sport, were examined. Bicycle ergometer testing to exhaustion was used (Oxycon Pro, Germany), cardiorespiratory parameters were analysed, maximal oxygen consumption (VO2 max) was determined, and the physiological cost of a unit of work was calculated. Results. At rest, a statistically significantly higher level of fitness was revealed in crosscountry skiers compared with biathletes according to such haemodynamic parameters as systolic blood pressure, pulse pressure, and double product. At maximal load, an increased degree of fitness was found in cross-country skiers in terms of power and duration of bicycle ergometer exercise, cardiac and pulse cost per unit of work, as well as gross and specific VO2 max. The body of cross-country skiers under the test to exhaustion (according to oxygen pulse value) functions more efficiently than the body of biathletes. Thus, higher level of fitness among cross-country skiers of the Komi Republic is manifested in the economization of cardiorespiratory functions both at rest and at maximal ergometric loads, as well as in the value of specific physiological cost per unit of work. Increased functionality (or reserves) of cross-country skiers is indicated by such parameters as systolic blood pressure, pulse pressure, double product, respiratory minute volume, oxygen consumption, and energy expenditure. It can be assumed that the aerobic performance of biathletes is lower than that of cross-country skiers as the former receive less training in cross-country skiing.

СПЕЦИАЛИЗИРОВАННЫЕ ВОЗРАСТНЫЕ И КВАЛИФИКАЦИОННЫЕ ХАРАКТЕРИСТИКИ ЭФФЕКТИВНОЙ АДАПТАЦИИ, ОТБОР ПО ПЕРСПЕКТИВНОСТИ И В СБОРНЫЕ КОМАНДЫ В СИСТЕМЕ ПОДГОТОВКИ СПОРТИВНОГО РЕЗЕРВА

Aim. The study aims to substantiate health monitoring, implement the effects of stress and adaptation, identify selection criteria and establish an integral rating indicator (IRI) in sports reserve training. Materials and methods. Representatives of cross-country skiing, swimming, middle-distance running, steeplechase, speed skating, wrestling, kickboxing, diving, orienteering, ice hockey were examined. The age of athletes varied from 18 to 22 years, their sports experience was 6–8 years. Sports skills level included the first adult category, Candidate for Master of Sport, Master of Sport, International Class Master of Sport. The following equipment was used in the study: Oxycon Pro Mobile, Schiller, Digi-Lite (Rimed), non-invasive AMP analyzer, MBN force platform, 3D scanner, polydynamometer, MARG 10-01 (Mikrolux). Data processing was performed with the methods of mathematical statistics. Results. Polyfunctional, metabolic, immunological features of resistance and special endurance were established. The criteria indicating successful sports performance, evaluative activity, connective tissue stability, neuroplasticity and adaptation were developed. Conclusion. The informative coefficients of statokinetic stability and resistance to hypoxia was obtained, as well as the integral rating indicator of successful competitive performance. An analysis of effective adaptation, fitness variability, normal limits, stable and premorbid health states, overtraining and overwork is proposed.

Current limits for flowmeter resistance in metabolic carts can negatively affect exercise performance.

PurposeTo investigate whether a metabolic cart using a flowmeter in the upper range of accepted resistance to airflow (<1.5 cmH2O∙L−1∙s−1 for flows up to 14 L∙s−1, American Thoracic Society) negatively impacts exercise performance in healthy individuals.Methods16 recreationally active males (age 25 ± 1 years, height 180 ± 6 cm, weight 73.5 ± 5.8 kg, all mean ± SD) performed two incremental tests on a bicycle ergometer on each of two visits, using a metabolic cart with a flowmeter of either low (Oxycon Pro) or high (Innocor) airflow resistance. Mouth pressures, gas exchange, blood lactate concentration [La−], perception of breathlessness, respiratory, and leg exertion were assessed throughout the tests.ResultsTests performed with the Innocor were significantly shorter (15.3 ± 3.2 vs. 15.8 ± 3.3 min, p < 0.0001) and showed higher maximal flow resistance (1.3 ± 0.2 vs. 0.3 ± 0.0 cmH2O∙L−1∙s−1, p < 0.0001). At end‐exercise, peak oxygen consumption (−200 ± 220 ml.min−1, p < 0.0001), minute ventilation (−19.9 ± 10.5 L.min−1, p < 0.0001), breathing frequency (−5.4 ± 5.2 breaths.min−1, p < 0.0001), heart rate (−2.1 ± 3.6 bpm, p = 0.002) and [La−] (−0.7 ± 1.0 mmol.L−1, p < 0.0001), but not tidal volume (−0.1 ± 0.2 L, p = 0.172) were lower with the Innocor, while the perception of breathlessness was higher (+3.8 ± 5.1 points, p < 0.0001).ConclusionsAirflow resistance in the upper range of current guidelines can significantly affect exercise performance and respiratory pattern in young, healthy males during incremental exercise. The present results indicate the need to revisit guidelines for devices used in ergospirometry.

Wrist-Worn Activity Trackers in Laboratory and Free-Living Settings for Patients With Chronic Pain: Criterion Validity Study.

BackgroundPhysical activity is evidently a crucial part of the rehabilitation process for patients with chronic pain. Modern wrist-worn activity tracking devices seemingly have a great potential to provide objective feedback and assist in the adoption of healthy physical activity behavior by supplying data of energy expenditure expressed as metabolic equivalent of task units (MET). However, no studies of any wrist-worn activity tracking devices’ have examined criterion validity in estimating energy expenditure, heart rate, or step count in patients with chronic pain.ObjectiveThe aim was to determine the criterion validity of wrist-worn activity tracking devices for estimations of energy expenditure, heart rate, and step count in a controlled laboratory setting and free-living settings for patients with chronic pain.MethodsIn this combined laboratory and field validation study, energy expenditure, heart rate, and step count were simultaneously estimated by a wrist-worn activity tracker (Fitbit Versa), indirect calorimetry (Jaeger Oxycon Pro), and a research-grade hip-worn accelerometer (ActiGraph GT3X) during treadmill walking at 3 speeds (3.0 km/h, 4.5 km/h, and 6.0 km/h) in the laboratory setting. Energy expenditure and step count were also estimated by the wrist-worn activity tracker in free-living settings for 72 hours. The criterion validity of each measure was determined using intraclass and Spearman correlation, Bland-Altman plots, and mean absolute percentage error. An analysis of variance was used to determine whether there were any significant systematic differences between estimations.ResultsA total of 42 patients (age: 25-66 years; male: 10/42, 24%; female: 32/42, 76%), living with chronic pain (duration, in years: mean 9, SD 6.72) were included. At baseline, their mean pain intensity was 3.5 (SD 1.1) out of 6 (Multidimensional Pain Inventory, Swedish version). Results showed that the wrist-worn activity tracking device (Fitbit Versa) systematically overestimated energy expenditure when compared to the criterion standard (Jaeger Oxycon Pro) and the relative criterion standard (ActiGraph GT3X). Poor agreement and poor correlation were shown between Fitbit Versa and both Jaeger Oxycon Pro and ActiGraph GT3X for estimated energy expenditure at all treadmill speeds. Estimations of heart rate demonstrated poor to fair agreement during laboratory-based treadmill walks. For step count, the wrist-worn devices showed fair agreement and fair correlation at most treadmill speeds. In free-living settings; however, the agreement for step count between the wrist-worn device and waist-worn accelerometer was good, and the correlation was excellent.ConclusionsThe wrist-worn device systematically overestimated energy expenditure and showed poor agreement and correlation compared to the criterion standard (Jaeger Oxycon Pro) and the relative criterion standard (ActiGraph GT3X), which needs to be considered when used clinically. Step count measured with a wrist-worn device, however, seemed to be a valid estimation, suggesting that future guidelines could include such variables in this group with chronic pain.

RESULTS OF A FIVE-YEARS FOLLOW-UP OF THE PHYSICAL PERFORMANCE OF YOUNG MALE SKIERS

The aim of the study was to assess physical performance over a five-years period in young male cross-country skiers living in the Russian North. Methods. Anthropometric data and parameters of blood circulation, respiration and energy expenditure were studied in 20 skiers aged 15-20 years in the Komi Republic. A bicycle ergometer with Oxycon Pro system (Germany) was the main assessment instrument. Tests were performed twice - at the beginning and in the end of a five-years period. Results. A statistically significant increase in body weight and body mass index, a decrease in heart rate (HR), systolic blood pressure, pulse pressure, double product (DP) and the vegetative Kerdo index at rest were observed indicating an increase in physical fitness. At a load of 200 W, a decrease in heart rate, DP, oxygen consumption and energy expenditure and an increase in efficiency were found suggesting economization of blood circulation and energy reactions during standard operation. However, at maximum load an increase in blood pressure from (185.0 ± 15.2) to (195.0 ± 11.6) mm Hg p = 0.038; a decrease in the maximum oxygen consumption from (67.4 ± 6.20) to (61.4 ± 7.21) ml / min x kg, p = 0.012; decreased oxygen consumption on the brink of anaerobic metabolism from (4,036 ± 594) to (3,623 ± 593) ml / min, P = 0.040; and heart rate on the brink of anaerobic metabolism from (171.0 ± 11.6) to (157.0 ± 16.5) bpm, p = 0.005 was revealed suggesting a decrease in the maximum functional capabilities of the body. Physiological costs of a unit of work for various indicators of blood circulation, respiration, and energy expenditure have not changed over a five-years period (p values varied from 0.082 to 0.935). Conclusions. The observed decrease in the level of physical performance by aerobic and anaerobic thresholds may suggest not only the beginning of age-related changes in the body of athletes in the North, but may also reflect possible negative impact of living conditions in the North.

INFLUENCE OF VEGETATIVE REGULATION OF HEART RHYTHM ON THE MANIFESTATION OF PHYSICAL PERFORMANCE OF QUALIFIED ATHLETES (І MESSAGE)

Introduction. To assess the characteristics of the body’s adaptation of skilled athletes to strenuous exercise, it is most important to define how the manifestation of physical performance of athletes depend on the autonomic regulation of physiological functions of the body. Aim is to study the dependence of the autonomic regulation of heart rate on the manifestation of physical performance of qualified athletes and the reaction of the cardiorespiratory system under conditions of physical activity of different nature. Materials and methods. Determination of physical performance of qualified athletes and the reaction of the cardiorespiratory system (CRS) to test physical activity (ergospirometric complex "Oxycon Pro", treadmill LE-200 C), mathematical analysis of heart rhythm variability, mathematical and statistical methods. Results. The predominance in the regulation of heart rate activity of the parasympathetic division of the autonomic nervous system helps athletes achieve a higher level of physical performance both in terms of physical activity with a predominance of aerobic processes in energy supply and in terms of maximum realization of aerobic capacity. Increased activity of the parasympathetic division of the autonomic nervous system is combined with a reduced level of VE, which indicates the efficiency of the reaction of cattle under physical conditions, mainly aerobic (low and medium power). With increasing intensity of physical activity (starting from the threshold of aerobic metabolism), the increased level of activity of the parasympathetic division of the autonomic nervous system will increase the level of pulmonary ventilation, which characterizes the most effective response of CRS Conclusions. The higher level of activity of the parasympathetic division of the autonomic emergency in the regulation of heart rate contributed to the formation of a more economical pattern of respiratory response due to higher VT and lower fT, which under intense physical work allowed to achieve higher levels of VE and aerobic potential of the athlete. With increasing activity of the sympathetic channel of heart rate regulation, there was a decrease in the efficiency of the respiratory response. Thus, the required operating level VE was formed due to the smaller value of VT at a high level

Assessing the validity of RMR equations in healthy Danish community-dwelling older adults

AbstractBackgroundEstimating basal energy requirements is important in terms of assessing energy balance and targeting nutritional support. Assessing Resting Metabolic Rate (RMR) via indirect calorimetry is considered a reliable way of estimating basal energy requirements. Several RMR equations have been developed during the past century through indirect calorimetry, but only few have specifically focused on older adults (&gt; 65 yrs). This may lessen the validity of the equations in relation to older adults, as body composition which is an important determinant for energy requirement changes considerably with age. Additional studies are therefore needed to assess the validity of available RMR equations in specific populations of older adults.AimThe aim of the present study was to investigate the validity of commonly available RMR equations in a group of older apparently healthy community-dwelling Danes (65 + y).MethodsRMR was measured by indirect calorimetry (mRMR) in 42 older individuals (10 females and 32 males; 65–81 years) participating in the CALM intervention study. Oxygen consumption and carbon dioxide production was measured for 25 min using a ventilated open hood system (Oxycon Pro 4; Jeager, Hoechberg, Germany). Predicted RMR (pRMR) was calculated using four different equations; the Harris-Benedict (1919) (HB), the Mifflin et al. (1990), the Lührmann et al. (2002) and the Henry et al. (2005) equations. The ratio between mRMR and pRMR (RMRratio) as well as the predictive ability (percentage of individual pRMR within + /-10% of mRMR) were calculated as a measure of validity.ResultsRMRratio for both sexes combined was 0.95 ± 0.08 for HB, 0.97 ± 0.07 for Mifflin et al., 0.92 ± 0.06 for Lürhmann et al. and 0.94 ± 0.07 for the Henry equations, respectively. The predictive ability was 73.8% (78.1% males and 60.0% of females, p = 0.410) for the HB, 81.0% (81.3% of males, and 80.0% of females, p≈1.00) for the Mifflin et al., 54.8% (56.3% of males and 50.0% of females, p≈1.00) for the Lührmann et al. equation, and 59.5% (59.4% of males and 60.0% of females, p≈1.00) for the Henry equations, respectively.ConclusionIn the present study, we found that the Mifflin equation was the most valid equations for predicting the RMR of older apparently healthy community-dwelling Danes. Generally, RMRratios and predictive ability were slightly lower for the H-B and Henry equations and lowest for the Lürhmann equation.

КАРДИОРЕСПИРАТОРНАЯ СИСТЕМА ПРИ ВЕЛОЭРГОМЕТРИЧЕСКОМ ТЕСТИРОВАНИИ У ЛЫЖНИКОВ РЕСПУБЛИКИ КОМИ С РАЗНОЙ СТЕПЕНЬЮ ТРЕНИРОВАННОСТИ

The aim of the study is to examine the impact of training status on ski racers (Komi Republic) at rest and under bicycle ergometry evaluating their cardiorespiratory system parameters. Materials and Methods. The authors examined male ski racers with different training status: 22 first-rank sportsmen, 22 candidates for Master of Sports and 22 Masters of Sports. Athletes underwent bicycle ergometry loads up to refusal. Oxycon Pro system (Germany) was used. Then authors studied the complex of cardiorespiratory parameters, calculating maximum oxygen consumption and unit physiological cost. Results. At rest and under standard physical load (200 W) Masters of Sports demonstrate significantly increased training status among ski racers in such cardiorespiratory system parameters as heart rate, rate pressure product and oxygen pulse. Under standard physical load (200 W) statistically significant differences between first-rank sportsmen and candidates for Master of Sports are detected by heart rate, rate pressure product, respiration rate, respiratory minute volume and oxygen utilization coefficient. Such deviations indicate differences in training status. Under maximum load, the highest training status is found in Masters of Sports: bicycle ergometry load power and duration; unit pulse, pressor and cardiac cost, bulk and unit values of maximum oxygen consumption. Heart rate values, unit pulse and heart-vent cost indicate a high training status in candidates for Master of Sports under load up to refusal, if compared with first-rank sportsmen. Athletes’ organism under load up to refusal works more efficiently than under moderate load (200 W). The training status in ski racers (Komi Republic) is manifested in the saving cardiorespiratory system functions, both at rest and under standard bicycle ergometry, as well as in parameters of unit physiological cost under loads up to refusal and increased values of maximum oxygen consumption. Keywords: ski racers, Komi Republic, training status, bicycle ergometry loads, cardiorespiratory system, maximum oxygen consumption.

ОСОБЛИВОСТІ СТРУКТУРИ ФУНКЦІОНАЛЬНОЇ ПІДГОТОВЛЕНОСТІ СПОРТСМЕНОК-ЛІДЕРІВ В ЖІНОЧОМУ БОКСІ

The article considers particularities of the functional and energy supply of the general physical working capacity of female boxers, which underlies in the basis of the high efficiency of the competitive activity. The objective – to establish peculiarities of the functional training degree of high-qualified athletes-leaders in female boxing. Methods. The manifestation of the working capacity and the reaction of the cardiorespiratory system to the test exertions, which allow to establish aerobic and anaerobic capabilities of the organism of female athletes, has been studied with the help of the ergospirometrical complex «Oxycon Pro». Results. In boxing the longer the duration of a combat the greater the values of the aerobic processes in its energy supply. Female athletes-leaders in female boxing are distinguished by the high level of the realization of their aerobic potential both under conditions of a continuous exertion and under conditions of short-term physical exertions, as well as by a higher speed of expanding of metabolic and functional reactions in transitional conditions of exertion. Conclusions. Aerobic and anaerobic capacity, mobility factor in the structure of the functional training degree of the female athletes-leaders in boxing allow adequately and quickly react to changes of the action intensity in a boxing combat, which facilitates the increase in the efficiency of the competitive activity.

Test-retest variability of VO2max using total-capture indirect calorimetry reveals linear relationship of VO2 and Power.

This study aimed to analyze the intra‐individual variation in VO2max of human subjects using total‐capture and free‐flow indirect calorimetry. Twenty‐seven men (27 ± 5 year; VO2max 49‐79 mL•kg−1•min−1) performed two maximal exertion tests (CPETs) on a cycle ergometer, separated by a 7 ± 2 day interval. VO2 and VCO2 were assessed using an indirect calorimeter (Omnical) with total capture of exhalation in a free‐flow airstream. Thirteen subjects performed a third maximal exertion test using a breath‐by‐breath calorimeter (Oxycon Pro). On‐site validation was deemed a requirement. For the Omnical, the mean within‐subject CV for VO2max was 1.2 ± 0.9% (0.0%‐4.4%) and for ergometer workload P max 1.3 ± 1.3% (0%‐4.6%). VO2max values with the Oxycon Pro were significantly lower in comparison with Omnical (P < 0.001; t test) with mean 3570 vs 4061 and difference SD 361 mL•min−1. Validation results for the Omnical with methanol combustion were −0.05 ± 0.70% (mean ± SD; n = 31) at the 225 mL•min−1 VO2 level and −0.23 ± 0.80% (n = 31) at the 150 mL•min−1 VCO2 level. Results using gas infusion were 0.04 ± 0.75% (n = 34) and −0.99 ± 1.05% (n = 24) over the respective 500‐6000 mL•min−1 VO2 and VCO2 ranges. Validation results for the Oxycon Pro in breath‐by‐breath mode were ‐ 2.2 ± 1.6% (n = 12) for VO2 and 5.7 ± 3.3% (n = 12) for VCO2 over the 1000‐4000 mL•min−1 range. On a Visual analog scale, participants reported improved breathing using the free‐flow indirect calorimetry (score 7.6 ± 1.2 vs 5.1 ± 2.7, P = 0.008). We conclude that total capturing free‐flow indirect calorimetry is suitable for measuring VO2 even with the highest range. VO2max was linear with the incline in P max over the full range.

FEATURES OF PULMONARY GAS EXCHANGE EXTERNAL BREATH REACTION TO LOCAL COLD INFLUENCE IN YOUNG ABLE-BODIED PERSONS

Intention. Aim? The effect of local cooling of the hand and foot skin on the functioning of pulmonary gas exchange in 30 young men and 30 girls aged 18-24 has been studied. Methods. At the initial stage of the study, an analysis of exhaled air was carried out with the ergospirometry system Oxycon Pro. The next stage consisted of carrying out a cold effect on the hand skin. The examinee put down a hand for 1 minute in a vessel with water with temperature successively was 24 °С, 15 °C and 8 °C. Right after local hypothermia repeated analysis of the exhaled air composition was carried out. The recovery interval between the tests was 25-30 minutes. The analysis of exhaled air was carried out during cooling of the foot in the same sequence. Results. A statistically significant increase in the ventilation equivalent for carbon dioxide (VECO2) by 5.4 % after cooling with a temperature of 8 °С and a ventilation equivalent for oxygen (VEO2) by 7.6 %, 7.6 %, and 6.4 % with cooling at 24 °С, 15 °С and 8 °С, respectively, were observed in girls while cooling the hand skin. There were also increase in the value of the respiratory coefficient (RC) at 24 °С by 3.9 % and at 8 °С by 2.6 %. A significant increase in RC by 7.8 % was also performed in young men while the local hypothermia of the hand at the temperature of 24 °С. An increase in VEO2 by 8.8 % in girls was observed in result of local cooling of the foot at the temperature of 24 °С. Influence of temperatures of 15 °С and 8 °С led to a significant increase in the indicator of VECO2 by 4.8 % and 7.6 %, and also by 8.4 % and 8.0 %, respectively. In addition, the cold influence on the foot skin in young men caused a significant decrease in the liberation rate of carbon dioxide (LRCO2) by 18.8 % while cooling at 24 °С, and at 8 °С by 17.1%. Conclusion. The reaction of pulmonary gas exchange to local cooling in girls is more pronounced than in young men and depends on the area of cooling and the temperature of exposure. The most significant changes are observed when the foot is locally cooled by the temperature of the water, causing a slight and strong body strain.

DYNAMIC OF PHYSICAL CAPACITY AND QUALITY OF LIFE AFTER HEART TRANSPLANTATION

Aim:to estimate physical capacity and quality of life (QoL) and defi ne factors which impact on their dynamic in recipients after heart transplantation (HTx).Materials and methods.From January 2010 to September 2016 we performed 76 HTx (mean age – 45,4 ± 1,6 yrs). Physical activity (PA) was evaluated by IPAQ questionnaire, QoL – by SF-36 (6 months and 1 yr after HTx). Patients underwent cardiopulmonary exercise test (Oxycon Pro, Germany) before, 6 months (n = 32) and 1 yr (n = 31) after HTx.Results.In 6 months after HTx PC improved (VO2peak – 12,6 ± 0,5 and 17,3 ± 0,6 ml/min/kg, p &lt; 0,001). One yr after HTx physically active recipients (n = 21) showed better results (VO2peak – 18,7 ± 0,9 vs. 16,7 ± 0,4 ml/min/kg, p &lt; 0,05). Moreover, 6 months 59,4% (n = 19) and 1 yr after HTx 77,4% (n = 24) of all patients reached normal values, 20 of them were physically active. We did not fi nd any difference in results depending on heart failure severity, duration of illness and of time spent in HT waiting list. In 6 months after HTx physical health (PH) increased (32,2 ± 1,1 vs. 48,2 ± 1,6, p &lt; 0,001), on the other hand, results of mental health (MH) were the same and remained stable in 1 yr after HTx. In addition, QoL was higher in physically active patients than in sedentary lifestyle ones. There was correlations between PH and PA duration (r = 0,4; p &lt; 0,05), VO2peak (r = 0,3; p &lt; 0,05), VO2 at AT (r = 0,4; p &lt; 0,05) and VE/VCO2 (r = –0,5; p &lt; 0,05).Conclusion.After heart transplantation physical capacity and physical health improved but physically active recipients showed better results. Factors affecting the increase in physical capacity were improvement in the functional state of the cardiovascular system and physical activity.