Metamax 3B Research Articles

Aerobic capacity in swimming, cycling and arm cranking in swimmers aged 11–13 years

BackgroundThis study aimed to compare the aerobic capacity in swimming, cycling and arm cranking in swimmers aged 11–13 years.MethodsEleven swimmers (mean age, 12.1 ± 1.0 years) performed three incremental exercise tests. One of the tests was performed under specific conditions (front crawl swimming), and the other two were under non–specific conditions (cycling and arm cranking). Data on the pulmonary gas exchange were recorded using the portable analyser MetaMax 3B (Cortex, Leipzig, Germany). One-way analysis of variance for repeated measures was employed to test the null hypothesis and determine statistically significant differences between the indicators obtained under specific and non–specific testing conditions. Pearson’s correlation coefficient was calculated to assess the relationships between the indicators of the pulmonary gas exchange.ResultsThe relative peak oxygen uptake (V̇O2peak) value during swimming was 49.3 ± 6.2 mL/kg/min, which was higher than that during arm cranking (39.6 ± 7.3 mL/kg/min; P < 0.01) but lower than that during cycling (54.3 ± 7.8 mL/kg/min; P < 0.01). The peak minute ventilation (V̇Epeak) value during swimming (84.9 ± 12.6 L/min) was higher than that during arm cranking (69.4 ± 18.2 L/min; P < 0.01) but lower than that during cycling (98.4 ± 15.4 L/min; P < 0.01). Strong positive correlations were observed in the absolute and relative V̇O2peak values between swimming and cycling (r = 0.857, P < 0.01; r = 0.657, P < 0.05) and between swimming and arm cranking (r = 0.899, P < 0.01; r = 0.863, P < 0.05). A strong positive correlation was also observed in V̇Epeak values between swimming and arm cranking (r = 0.626, P < 0.05).ConclusionSwimmers aged 11–13 years showed V̇O2peak and V̇Epeak values during the specific swimming test greater than those during arm cranking but lower than those during cycling. However, aerobic capacity parameters measured during specific swimming conditions correlated with those measured during non–specific arm cranking and cycling conditions.

Validity of Apple Watch, Garmin Forerunner® 935 and GENEActiv for estimating energy expenditure during close quarter battle training in Special Forces soldiers

AbstractThe purpose of this study was to investigate the validity of three wrist‐worn devices for estimating energy expenditure (EE) and heart rate (HR) during close “Close Quarter Battle” (CQB). Fifty male soldiers (mean ± SD: age 30.9 ± 4.6 years, height: 1.81 ± 0.64 m and body mass 87.3 ± 7.7 kg) wore three activity monitors (Apple Watch 5, Garmin Forerunner® 935 and GENEActiv accelerometer), a Metamax 3B metabolic cart and a Polar chest strap, whilst conducting a CQB training activity (duration: 26.6 ± 5.0 min). EE and HR data from each test device were compared against criterion measures using ordinary least products regression, 95% limits of agreement, equivalence testing and Mean Absolute Percentage Error (MAPE). Based upon the criterion measure the mean EE for the activity was 372.2 ± 57.6 kcal. All of the devices tested demonstrated fixed and/or proportional bias for EE and a MAPE of &gt;10% (Apple 11.3%, Garmin 15.3%, GENEActiv 57.7%) and therefore did not agree with the criterion. The Apple Watch was a valid method for measuring HR, with a MAPE of 0.6%, and differences with the criterion falling within acceptable limits (≤1 bpm = 83.7%; ≤3 bpm = 97.5% and ≤5 bpm = 97.5%), whereas the Garmin Forerunner® 935 was not valid for measuring HR due to an unacceptable difference compared to the criterion (≤1 bpm = 19.1%; ≤3 bpm = 33.3% and ≤5 bpm = 45.2%). Overall, the Apple Watch 5 can be recommended for measuring HR, but none of the devices are recommended for estimating EE, during CQB.

The test–retest reliability of physiological and perceptual responses during treadmill load carriage

PurposeUnderstanding the test–retest reliability of physiological responses to load carriage influences the interpretation of those results. The aim of this study was to determine the test–retest reliability of physiological measures during loaded treadmill walking at 5.5 km h−1 using the MetaMax 3B.MethodsFifteen Australian Army soldiers (9 male, 6 female) repeated two 12-min bouts of treadmill walking at 5.5 km h−1 in both a 7.2 kg Control condition (MetaMax 3B, replica rifle) and a 23.2 kg Patrol condition (Control condition plus vest) across three sessions, separated by one week. Expired respiratory gases and heart rate were continuously collected, with the final 3 min of data analysed. Ratings of Perceived Exertion and Omnibus-Resistance Exercise Scale were taken following each trial. Reliability was quantified by coefficient of variation (CV), intra-class correlation coefficients (ICC), smallest worthwhile change (SWC), and standard error of the measurement.ResultsMetabolic and cardiovascular variables were highly reliable (≤ 5% CV; excellent-moderate ICC), while the respiratory variables demonstrated moderate reliability (< 8% CV; good-moderate ICC) across both conditions. Perceptual ratings had poorer reliability during the Control condition (12–45% CV; poor ICC) than the Patrol condition (7–16% CV; good ICC).ConclusionsThe test–retest reliability of metabolic and cardiovascular variables was high and relatively consistent during load carriage. Respiratory responses demonstrated moderate test–retest reliability; however, as the SWC differed with load carriage tasks, such data should be interpreted independently across loads. Perceptual measures demonstrated poor to moderate reliability during load carriage, and it is recommended that they only be employed as secondary measures.Graphical abstract

Normobaric hypoxia and exercise training effects on cardiac biomarkers, left ventricular function and aerobic performance in patients after myocardial infarction

Abstract Background Chronic total occlusion (CTO) has a negative impact on the left ventricle function and long-term prognosis of the patients after myocardial infarction. Scientific evidence suggests that some patients with CTO develop collateral arteries which provide an alternative source of blood supply to myocardium and can help to preserve myocardial function. One of the factors influencing the formation of collateral circulation is hypoxia, which induces angiogenesis and arteriogenesis. Physical activity is the most effective stimulus for adaptive changes in cardiovascular hemodynamics. However, the use of hypoxia and endurance exercise training on hemodynamic parameters of the heart and angiogenic factors have not been thoroughly studied yet. The aim of the present study was to examine the effect of endurance training under normobaric hypoxia on cardiac-specific troponin T (cTnT), creatinine kinase-myocardial band (CK-MB), heart-type fatty acid binding protein (H-FABP), vascular endothelial growth factor (VEGF), cytokines and cardiovascular function in patients after myocardial infarction. Methods Patients aged 60.4 ± 4.4 years who had undergone angioplasty with stent implantation participated in the study. Due to high risk of the occurrence of side effects cause by normobaric hypoxia only patients with stable coronary diseases (participants of the second stage of cardiac rehabilitation program) were included. The training program included 3 weeks of endurance training in normobaric hypoxia (HypTr) corresponding to an altitude of 2000 m above the sea level (FiO2 = 15.0%; (HYP-123 Hypoxic Generator, LOWOXYGEN Technology GmbH, Germany). The training regimen comprised 5 sessions/week with 5 min of warm-up, 30 min of interval training (intensity 80% of HRpeak) and 5 min of cooling down. Spiroergometry (CORTEX METAMAX 3B analyzer ) was performed using the cardiopulmonary test Electrocardiography and cardiac biomarkers were evaluated before and after the three weeks of the training programme. Results An increase in average distance covered (622.7 ± 119.0 vs. 687.0 ± 126.7 m, p&amp;lt;0.01) and the test duration (10.4 ± 1.0 vs. 11.0 ± 1.7 m, p&amp;lt;0.05) were observed in response to exercise training in hypoxia. CK-MB (p&amp;lt;0.05) and cTnT (p&amp;lt;0.05) levels were lower post-training compared to the pre-training (p &amp;lt; 0.05). Training in hypoxia had a significant effect on hemoglobin (F=14.7 p&amp;lt;0.001), TNF β (F = 8.2 p&amp;lt;0.01) and VEGF (F = 7.4 p&amp;lt;0.1) levels. Left ventricular (LV) function was altered post-training and the alteration was characterized by favorable changes in end-diastolic and end-systolic dimensions and LV ejection fraction (p&amp;lt;0.05). Conclusions Exercise training in normobaric hypoxia had a significant positive effect on the left ventricular function and concentration of the specific cardiac biomarkers, therefore it may play a crucial role in the cardiovascular adaptive mechanisms in patients after myocardial infarction.

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.

Physical activity when riding an electric-assisted bicycle with and without cargo.

Regular physical activity provides several health benefits, and active transport is a convenient way to implement physical activity in everyday life. However, bikes' lack of possibilities to carry cargo is a limitation. E-cargo bikes can help overcome barriers to cycling and increase levels of active transport while still providing the option to carry cargo such as groceries and children. As such, E-cargo bikes have a greater potential for being a substitute for cars, but relevance is not known as no study has assessed the energy expenditure and time used using E-cargo bikes with considerable cargo. The aim of this study is to compare time spent riding and exercise intensity when (1) riding an electric-assisted bicycle with cargo (30 kg) and without cargo and (2) driving a car. This study has a randomised crossover design. Eleven participants (six women) were recruited through convenience sampling. The participants traversed through a 4.5 km route with three different forms of transportation: an electric-assisted bicycle (E-bike) with 30 kg cargo, an E-bike without cargo, and a car. Oxygen uptake was measured with a portable oxygen analyser (Metamax 3B), and time spent cycling was measured on site by the test leader using a stopwatch. Riding an E-bike with cargo was slightly slower than riding an E-bike without cargo (11.8 vs. 11.1 min, p = 0.017) and driving a car (8.8 min, p = 0.002). There was no significant difference in exercise intensity between E-bikes with and without cargo but riding an E-bike with cargo entailed significantly higher exercise intensity compared to driving a car [4.9 metabolic equivalents of task (METs) vs. 1.4 METs, p ≤ 0.001]. E-biking with cargo was rather similar in time spent and exercise intensity to E-biking without cargo, and not much slower than driving a car. Using E-cargo bikes, therefore, appears a good alternative to driving a car when in need of carrying things such as grocery bags and children, resulting in increasing physical activity and, at the same time, decreasing greenhouse gas emissions.

Effects of a training intervention tailored to the menstrual cycle on endurance performance, recovery and well-being in female recreational runners – A randomized-controlled pilot study

Effects of a training intervention tailored to the menstrual cycle on endurance performance, recovery and well-being in female recreational runners – A randomized-controlled pilot study

Характеристика стійкого стану функцій спортсменів у видах спорту з варіативними умовами змагальної діяльності

The purpose of the study was to develop generalized and specific characteristics of the steady state of the highly qualified athletes, who specialize in the standard program of sports dance and boxing. Materials and methods. Twenty sportsmen-dancers and twenty boxers of high qualification took part in the research. Gas analysis. Measurements of О2 consumption reaction, СО2 emissions, minute volume of breathing were carried out using the MetaMax 3B analyzer. Ergometry. Modeling of standard conditions of measurement was carried out on the basis of bicycle ergometer Monark. Standard conditions are associated with the use of a given ergometric load power of 50 W. The composition of Cardiorespiratory Intermittent endurance test included eight accelerated 10-second intervals, eight 20-second rest intervals. The duration of the task is four minutes. Mathematic statistics. Descriptive statistics suggested determining the arithmetic mean – x ̅, standard deviation – S, as well as median – Me, maximum (max) and minimum (min) indices, 25% and 75% indices. Steady state is a period of competitive activity, in the process of which sportsmen demonstrate high level of technical and tactical skills and physical performance. Steady state diagnostics is an essential reserve for managing the functional support of special performance of athletes in sports with variable conditions of competitive activity. Results and discussion. An increase in the response of pulmonary ventilation indicates its role as a response to respiratory compensation of metabolic acidosis. Differences in the breathing response in standard measurement conditions are related to the specificity of the breathing response of athletes-dancers. To some extent, “artificial” management of the breathing response causes a decrease in the intensity of breathing cycles. Empirical knowledge indicates that this refers to the “aesthetic” component of the judges' assessment of the performance of the sports dance program. To some extent, this is related to the specifics of the formation of programs of special physical training, correction of certain structural components of functional maintenance of working capacity, in this case, the respiratory system. Another obvious fact is related to the structure of the load, when the intensity of the work of boxers causes more significant acidemic shifts and, as a result, predicts an increase in the reaction of pulmonary ventilation as a mechanism for removing excess CO2 during work. The increase (maintenance) of the O2 consumption response of athletes-dancers is associated with the formation of excess CO2 within the RER – 1.03–1.05 and excessive pulmonary ventilation in the range of 37.2–39.1. Boxers, respectively, with the formation of excess CO2 within the limits of RER – 1.07–1.09 and excessive pulmonary ventilation in the range of 40.0–44.1. The increase in excess ventilation in the third-fifth of dancers was 4.9%, 9.9% – in boxers, provided that the O2 consumption reaction remained stable. Conclusion. The steady state of the functional support of the special performance of athletes in sports with variable conditions of competitive activity ensures the stable development of cardio-respiratory system and aerobic energy supply in the middle of intense motor activity

Energy Expenditure Characteristics Of Chinese Square Dance

PURPOSE: The purpose of this study was to determine the energy expenditure characteristics of three different types of square dance (ballet style, Tibetan dance and aerobic dance). METHODS: 32 Chinese adults volunteered the test, including 17 women (mean ± SD: 21.4 ± 2.6 yrs,167.9 ± 3.9 cm, 56.2 ± 4.19 kg) and 15 men (22.3 ± 1.8 yrs, 177.7 ± 5.1 cm, 69.5 ± 7.0 kg). All participants performed 3 different kinds of square dance routines . Height, weight and body composition were assessed before the testing session. Gas exchange and heart rate (HR) were recorded using indirect calorimetry (Meta Max 3B, Cortex Biophysic, Leipzig, Germany) and HR monitor (V800, Polar, Finland) continuously before, during and after each test. Energy expenditure (EE), metabolic equivalent of energy (METs), HR and post-exercise oxygen consumption (EPOC) were collected and statistically analyzed. RESULTS: EE, METs, HR and EPOC of aerobic dance were significant higher than ballet style and Tibetan dance (p < 0.05) (Data showed in Table 1). EE (ballet style: 5.99 ± 1.11 vs. 4.63 ± 0.76; Tibetan dance: 6.41 ± 1.27 vs. 4.65 ± 0.76; aerobic dance: 8.46 ± 1.53 vs. 6.12 ± 0.78) and EPOC (ballet style: 1.75 ± 0.50 vs. 1.42 ± 0.31; Tibetan dance: 2.20 ± 0.76 vs. 1.56 ± 0.21; aerobic dance: 2.65 ± 1.16 vs. 1.81 ± 0.30) of male were higher than female of each square dance (p < 0.05). There was no significant difference in METs between genders (ballet style: 5.06 ± 0.88 vs. 5.48 ± 0.79; Tibetan dance: 5.45 ± 1.10 vs. 5.59 ± 0.92; aerobic dance: 7.14 ± 1.27 vs. 7.22 ± 0.77, p > 0.05). CONCLUSIONS: Square dance is a moderate-to-vigorous-intensity activity, which is related to the type. The energy expenditure and post-exercise oxygen consumption of the three dances are affected by gender, and males are higher than females.

Wrist-worn devices for the measurement of heart rate and energy expenditure: A validation study for the Apple Watch 6, Polar Vantage V and Fitbit Sense

ABSTRACT The purpose of this study was to investigate the accuracy of 3 recently released wrist-worn devices (Apple Watch 6, Polar Vantage V and Fitbit Sense) for heart rate and energy expenditure during various activities. The study population consisted of 60 young healthy individuals (30 men and 30 women; age: 24.9 ± 3.0 years, BMI: 23.1 ± 2.7 kg/m2). Heart rate and energy expenditure were measured using the Polar H10 and Metamax 3B, respectively (reference measures) as well as with the 3 wrist-worn devices during 5 different activities (sitting, walking, running, resistance exercises and cycling). The Apple Watch 6 displayed the highest level of accuracy for heart rate measurement with a coefficient of variation (CV) (%) of less than 5% for all 5 activities, whereas the Polar Vantage V and the Fitbit Sense presented various degrees of accuracy (from high to poor accuracy) dependent on the activity (CVs between 2.44-8.80% and 4.14-10.76%, respectively). As for energy expenditure, all 3 devices displayed poor accuracy for all 5 physical activities (CVs between 14.68-24.85% for Apple Watch 6, 16.54-25.78% for Polar Vantage V and 13.44-29.66% for Fitbit Sense). Results of the present study indicate that the Apple Watch 6 was the most accurate for measuring heart rate across all 5 activities, whereas variable levels of accuracy for heart rate measurement for the Polar Vantage V and the Fitbit Sense were observed depending on the activity. As for energy expenditure, all 3 devices showed poor accuracy during all activities. Highlights The Apple Watch 6 was the most accurate for measuring heart rate, whereas the Polar Vantage V and Fitbit Sense showed variable results dependent on the activity The Apple Watch 6, Polar Vantage V and Fitbit Sense showed poor accuracy for energy expenditure during 5 different physical activities Healthcare care professionals, athletes/coaches and the general population may want to proceed with caution on the clinical utility of energy expenditure of these devices during the implementation of an exercise training or nutritional programme.

Validation of ambulatory monitoring devices to measure energy expenditure and heart rate in a military setting

Objectives.To investigate the validity of different devices and algorithms used in military organizations worldwide to assess physical activity energy expenditure (PAEE) and heart rate (HR) among soldiers. Design. Device validation study. Methods. Twenty-three male participants serving their mandatory military service accomplished, firstly, nine different military specific activities indoors, and secondly, a normal military routine outdoors. Participants wore simultaneously an ActiHeart, Everion, MetaMax 3B, Garmin Fenix 3, Hidalgo EQ02, and PADIS 2.0 system. The PAEE and HR data of each system were compared to the criterion measures MetaMax 3B and Hidalgo EQ02, respectively. Results. Overall, the recorded systematic errors in PAEE estimation ranged from 0.1 (±1.8) kcal.min−1 to −1.7 (±1.8) kcal.min−1 for the systems PADIS 2.0 and Hidalgo EQ02 running the Royal Dutch Army algorithm, respectively, and in the HR assessment ranged from −0.1 (±2.1) b.min−1 to 0.8 (±3.0) b.min−1 for the PADIS 2.0 and ActiHeart systems, respectively. The mean absolute percentage error (MAPE) in PAEE estimation ranged from 29.9% to 75.1%, with only the Everion system showing an overall MAPE <30%, but all investigated devices reported overall MAPE <1.4% in the HR assessment. Conclusions. The present study demonstrated poor to moderate validity in terms of PAEE estimation, but excellent validity in all investigated devices in terms of HR assessment. Overall, the Everion performed among the best in both parameters and with a device placement on the upper arm, the Everion system is particularly useful during military service, as it does not interfere with other relevant equipment.

Effects Of Pyruvate On Aerobic Energy Contribution And Lactate Acidosis Of High-intensity Interval Exercise

Maintain a stable acid-base balance is essential for exercise performance. Pyruvate has obvious benefits to attenuate acidosis. However, the role of pyruvate on acid-base buffer during high-intensity interval exercise (HIIE) remains unclear. PURPOSE: Assess the role of pyruvate on HIIE induced lactate acidosis from the perspective of energy metabolism. METHODS: In this double-blind, randomized, crossover trial, 14 male college football players (age: 20 ± 2 yrs; body fat: 13.11 ± 3.50%) were determined maximal aerobic power output using progressive ergometer cycle test. After one week of wash out period, they supplied sodium pyruvate or placebo (0.1 g/kg/d) for 7 days. Sixty minutes after the last ingestion, resting oxygen consumption rate was collected. Then, subjects performed HIIE (4*1 min 110% VO2max, interval 1 min rest) to induce lactate acidosis. Venous and fingertip blood samples were collected for blood gas and lactate analysis. A portable Cortex Metamax 3B gas analysis system was used to measure oxygen consumption. Aerobic energy or ATP-PCr energy contribution: resting oxygen consumption was subtracted from the oxygen consumption obtained during each 110% VO2max or 1-min resting bout. Lactate difference before and after each 110% VO2max bout assumed to calculate glycolytic energy contribution. 1 mM of lactate corresponds to 3 ml of oxygen/kg of body mass. 1 L of oxygen corresponds to 20.92 kJ. RESULTS: Aerobic energy contribution of fourth 110% VO2max bout was significantly improved in pyruvate than placebo group (59.14 ± 7.07 kJ vs. 50.26 ± 10.72 kJ, p < 0.05). ATP-PCr and glycolytic energy contribution were not obviously changed. Blood pH (7.40 ± 0.03 vs. 7.37 ± 0.03, p < 0.01 ), HCO3- (26.09 ± 0.82 vs. 24.86 ± 1.03, p < 0.01), BE (3.39 ± 0.86 vs. 2.06 ± 0.41, p < 0.01) before HIIE and Blood pH (7.20 ± 0.05 vs. 7.14 ± 0.08, p < 0.05 ), HCO3- (14.56 ± 1.83 vs. 12.94 ± 2.25, p < 0.05) , BE (-12.79 ± 3.22 vs. -15.61 ± 4.39, p < 0.05) after HIIE in pyruvate group were significant higher than placebo group. CONCLUSIONS: The finding suggests that pyruvate supplementation can improve HIIE-induced lactate acidosis and aerobic energy contribution, which might indicate that pyruvate buffers HIIE-induced lactate acidosis by improving aerobic oxidation capacity.

Respiratory, cardiac and metabolic responses during electrical muscle stimulation in quadriceps muscle versus comparable voluntary muscle contractions

Electrical Muscle Stimulation (EMS) and voluntary muscle contraction (VMC) are both acceptable rehabilitative modalities to preserve muscle strength loss. The study aimed to compare respiratory, metabolic, and cardiac parameters during quadriceps muscle contraction (QMC) using either EMS or VMC with comparable generated low intensity muscle force. Thirty healthy non-smoker males, age 20–58 years with normal BMI and low to moderate physical activity, underwent two 20-min sessions of comparable QMC using EMS vs VMC at the same day. The BIODEX III isokinetic dynamometer was used to assess maximum isometric force and the comparable force generated during each condition (EMS vs VMC), while the METAMAX 3B portable metabolic system was used to measure continuously the physiological parameters. Tolerable EMS was used (mean: 33 ± 1.5 mA, at 75 Hz). Each contraction lasted 10 sec followed by 20 sec rest. Paired t-tests were used for comparisons between sessions. A relatively low proportion of maximum isometric force (EMS: 8.5% vs VMC: 8.6%) and torque (EMS: 16 ± 1.3 vs VMC: 16 ± 1.1 Nm) were generated during each session. Mean minute ventilation (EMS: 10.8 L vs VMC: 9.8 L), tidal volume (EMS: 0.6 L vs VMC: 0.5 L), O2 uptake (EMS: 0.31 L/min vs VMC: 0.26 L/min) and O2 pulse (EMS: 3.9 ml/beat vs VMC: 3.6 ml/beat) were different between sessions (p ≤ .05); while heart rate (EMS: 72 beats/min vs VMC: 71 beats/min) was equal. Quadriceps muscle EMS induces higher respiratory and metabolic responses compared to equal magnitude VMC in healthy males.

ЗВ’ЯЗОК ФІЗИЧНОЇ ПРАЦЕЗДАТНОСТІ ТА БІОЕНЕРГЕТИЧНИХ МЕХАНІЗМІВ ЗАБЕЗПЕЧЕННЯ ІГРОВОЇ ДІЯЛЬНОСТІ ФУТБОЛІСТІВ

Introduction. All the parameters of physical performance are important for achieving high results in footbal. A very small number of works are devoted to the study of bioenergy support of the game activity of different roles football players. High sports results can be achieved by athletes in football who have a high level of physical performance. Purpose . The purpose of our research was to find out the peculiarities of bioenergy provision of physical performance under the condition of football players' game activity. Methods. The experiment involved 29 highly qualified professional footballers. The results of the physical performance were received by the device GPS-sport system “Catapult”, pulsometer “Polar”, bicycle ergometer “Monarkh” and using an Meta Max 3B gas analyzer “Cortex” recorded oxygen consumption . Results. T he connection between physical performance and bioenergetic characteristics of anaerobic and aerobic support has been established for skilled footballers. The correlation between the length of the distance during the game and the indicators W of the ergometric test at the level of PANO was r = 0.43 (p <0.032), and for VO2max, r = 0.41 (p <0.027) and with HR - r = 0.37 (p <0.047). The results of this research demonstrated that the aerobic mechanism is the dominant energy system (76%) in providing special physical performance under the condition of football players' game activity. The smallest contribution to the physical performance of football players during the game was made by anaerobic lactate and lactate energy supply mechanisms, respectively - 5.6% and 1.6%. Conclusion . The characteristics of HR, VO2max, W and indicators of physical performance in different modes of energy supply during the game are informative criteria for assessing the functional state of the athlete, fitness, physical and functional fitness of players and can be used to control the training process and forecast game activity of football players.

Accuracy of the Multisensory Wristwatch Polar Vantage's Estimation of Energy Expenditure in Various Activities: Instrument Validation Study.

BackgroundSport watches and fitness trackers provide a feasible way of obtaining energy expenditure (EE) estimations in daily life as well as during exercise. However, today’s popular wrist-worn technologies show only poor-to-moderate EE accuracy. Recently, the invention of optical heart rate measurement and the further development of accelerometers in wrist units have opened up the possibility of measuring EE.ObjectiveThis study aimed to validate the new multisensory wristwatch Polar Vantage and its EE estimation in healthy individuals during low-to-high-intensity activities against indirect calorimetry.MethodsOverall, 30 volunteers (15 females; mean age 29.5 [SD 5.1] years; mean height 1.7 [SD 0.8] m; mean weight 67.5 [SD 8.7] kg; mean maximal oxygen uptake 53.4 [SD 6.8] mL/min·kg) performed 7 activities—ranging in intensity from sitting to playing floorball—in a semistructured indoor environment for 10 min each, with 2-min breaks in between. These activities were performed while wearing the Polar Vantage M wristwatch and the MetaMax 3B spirometer.ResultsAfter EE estimation, a mean (SD) of 69.1 (42.7) kcal and 71.4 (37.8) kcal per 10-min activity were reported for the MetaMax 3B and the Polar Vantage, respectively, with a strong correlation of r=0.892 (P<.001). The systematic bias was 2.3 kcal (3.3%), with 37.8 kcal limits of agreement. The lowest mean absolute percentage errors were reported during the sitting and reading activities (9.1%), and the highest error rates during household chores (31.4%). On average, 59.5% of the mean EE values obtained by the Polar Vantage were within ±20% of accuracy when compared with the MetaMax 3B. The activity intensity quantified by perceived exertion (odds ratio [OR] 2.028; P<.001) and wrist circumference (OR −1.533; P=.03) predicted 29% of the error rates within the Polar Vantage.ConclusionsThe Polar Vantage has a statistically moderate-to-good accuracy in EE estimation that is activity dependent. During sitting and reading activities, the EE estimation is very good, whereas during nonsteady activities that require wrist and arm movement, the EE accuracy is only moderate. However, compared with other available wrist-worn EE monitors, the Polar Vantage can be recommended, as it performs among the best.

Quantification of energy expenditure during daily living activities after stroke by multi-sensor

ABSTRACTObjective: To explore the validity of energy expenditure estimates using the SenseWear Armband during a sequence of four daily living activities in patients post-stroke.Method: Patients with stroke who were able to walk during 6 min without human assistance were asked to wear the SenseWear Armband on the non-paretic arm while performing transfers, a manual task, walking, and walking up and down stairs. The energy expenditure estimated using the SenseWear Armband was compared to the energy expenditure calculated from oxygen consumption, measured by a portable indirect calorimeter (Metamax 3B). The mean of energy expenditure was pooled for each task. Accuracy was explored by mean bias (MB) of Bland–Altman analysis and root mean square error (RMSE), agreement by 95% of limits of agreement (95%LoA) and coefficient of correlation (r).Results: Thirty-eight participants (65.7 ± 13.5 years) were included. The SenseWear Armband globally underestimated energy expenditure, MB = 9.77 kcal for the whole sequence. RMSE were large, accounting for 15% to 41% of the measured energy expenditure. Agreement was low with r < 0.70 and 95%LoA from 42% to 93% of the measured energy expenditure.Conclusions: This study reported a global underestimation and a low level of agreement of the energy expenditure estimated by SenseWear Armband in four daily living activities in patients after stroke.Abbreviations: EE: Energy Expenditure; NIHSS: National Institute of Health Stroke Score

Relationship Of Leptin,Body Composition And Resting Metabolic Rate In Chinese Overweight And Obese Adults

PURPOSE: Resting metabolic rate (RMR) and substrate utilization are important factors in maintaining energy balance and leptin is postulated to be involved in the regulation of body weight. However, in overweight and obese individuals, excess fat mass has a significant impact on metabolic function both directly through altered metabolic rate and substrate oxidation, and indirectly, through chronic changes in hormonal concentrations. This study determined the relationship of body composition and leptin with RMR and substrate utilization (carbohydrate, fat and protein oxidation rates) in Chinese overweight and obese adults. METHODS: The subjects were 33 women (age = 44.0±12.1 years; BMI =27.9±3.2 kg/m2; percent body fat (%fat) = 38.7 ± 4.0%) and 34 men (age= 30.0±9.7years; BMI=27.4±1.7 kg/m2; percent body fat (%fat) = 27.5 ± 4.3%). RMR and substrate utilization were measured by indirect calorimetry (Metamax 3B® Metabolic Measurement system, German) and body composition by the bioelectrical impedance method. Serum leptin levels were determined by radioimmunoassay. RESULTS: In men and women, RMR significantly correlated with Skeletal Muscle Mass (Men: R=0.556, p=0.001; Women: R=0.493, p=0.004), but both not significantly correlated with leptin(both p>0.05). In stepwise multiple regression analysis, SMM was the main predictor of RMR, explaining 42.5% and 28.5% of the variance of RMR in men and women respectively. In women, but not men, leptin significantly correlated with RER (R=-0.581, p=0.029) and carbohydrate, fat, and protein oxidation rates respectively (R=-0.558, 0.689, 0.690; all p<0.01).Furthermore,in stepwise multiple regression analysis, leptin explaining 33.7% of the variance of RER in women. CONCLUSIONS: Skeletal Muscle Mass is a significant predictor of RMR in Chinese overweight and obese adults, evaluation of body composition may be an effective and efficient way to evaluate metabolic status. Serum leptin concentrations in female subjects showed a negative association with respiratory quotient and carbohydrate oxidation rate and positive association with fat and protein oxidation rates. We suggest that sex-specifc evaluations are also necessary. Acknowledgements: This work was supported by National science and technology program of China (Grants No.2013FY114700)

Basal energy expenditure, resting energy expenditure and one metabolic equivalent (1 MET) values for young Chinese adults with different body weights.

Accurately assessing energy expenditure (EE) of people with different body weight is essential to facilitate weight management. The aim of this study was to measure basal energy expenditure (BEE), resting energy expenditure (REE) and to explore the true 1 MET value for young Chinese adults with different body weight. A total of 251 young Chinese adults were divided into three groups: the normal weight group, the overweight group and the obese group. Their BEE, REE and 1 MET values were measured by Cortex Metamax 3B (MM3B). Multiple linear regressions and correlation analysis were used to examine factors that influence EE in Chinese population. The mean measured BEE and REE of young Chinese adults with normal weight, overweight and obesity was 1429, 1609, 1778 kcal/day and 1522, 1712, 1885 kcal/day, respectively. The EE per kilogram body weight decreased with the increasing body weight. The mean oxygen consumption in the three group was 3.78, 3.47, 3.21 mL/kg/min respectively. There was no significant difference in BEE and REE after adjustment for fat-free mass (FFM). The significant influencing factors were body mass index (BMI) and sex in BEE, FFM and BMI in REE in Chinese population. BEE and REE were significantly different for different body weights while these differences disappeared after adjustment for FFM, and people with different body weights may have different 1 MET values. Further studies should be conducted to obtain more accurate daily energy requirement and 1MET value for specific Chinese populations.

PO-268 Heart rate variability to assess ventilatory threshold in overweight young men

Objective The individualized training intensity is important in the prevention of overweight and obesity. Our study compared heart rate (HR), oxygen uptake (VO2), and work load (WL) corresponded to the anaerobic threshold during an incremental cycling test between ventilatory (VT) and heart rate variability threshold (HRVT) methods. Further, we examined the validity of three heart rate variability analyses to assess VT in overweight young men.&#x0D; Methods Sixteen overweight young men (age 21.1±1.7 years, height 175.3±5.5 cm, weight 84.0±6.7kg, body mass index 27.3±1.2 kg/m2, VO2peak33.6±4.3ml/min/kg ) performed a gradual exercise test on a cycle ergometer (Lode Corival，Lode B.V.，Groningen，Newtherlands).The protocol started at 30 W for 2 minutes with subsequent increments of 30 W every 2 minutes until exhaustion. During test, gas exchanges (VO2, VCO2) and ventilation (VE) were measured by breath-by-breath using Metamax 3B portable analyzer (CORTEX, Biophysik GmbH，Leipzig，Germany). The ventilatory threshold (VT) was identified as the point at which VE for O2 began to rise without a concomitant rise in ventilator equivalent for CO2. The R-R intervals were continuously recorded using a Polar RS800cx HR monitor(Kempele, Finland). HRV data were further analyzed by Kubios HRV analysis software (Kuopio, Finland) based on time-domain (RMSSD) , Poincare plots(SD1) and time-varying spectral (fHF×HFP) methods. Data were analyzed using SPSS 22.0. Normal distribution of variables was verified by Kolmogorov-Smirnov test. The relationship between HRVT variables and VT was assessed using paired t-test and Pearson’s production correlation. The magnitude of concordance between the methods was further evaluated by Bland-Altman plots.&#x0D; Results No significant difference was witnessed in HR, VO2, and WL related to AT between HRVT and VT methods（P&lt;0.05）. The relationships were found between the methods to determine the AT for all variables analyzed (r=0.40-0.91). Additionally, the Bland-Altman plots revealed that findings showing narrow limits of agreement present for fHF×HFP and the VT whilst the association between RMSSD, SD1 and VT showed wider limits.&#x0D; Conclusions The estimation of the HRVT, especially derived through the time-varying spectral (fHF×HFP), may be a noninvasive and more robust method to determine the VT, which could be used to adapt individualized training intensity to overweight young men for training prescription.&#x0D;

PL-014 The gaseous metabolism characteristics of overweight adult women during exercise stress test

Objective Overweight was a global public health problem. In recent years, the number of overweight people in China had been increasing. Being overweight had a serious impact on health. 31.1% of overweight people had aggregation of risk factors for cardiovascular metabolic diseases. And overweight people were more likely to suffer from some diseases, such as hypertension, diabetes, dyslipidemia and arthritis. This study compared the gas metabolism index differences between overweight and normal weight women when they did exercise under different load, and summarized gas metabolism characteristics of overweight women, in order to lay the foundation for instructing overweight women to do exercise scientifically, reduce the risk factors of chronic diseases such as cardiovascular disease, and enhance and improve physical fitness and health.&#x0D; Methods Adult women between 20 and 30 years were taken as subjects. After measuring their height and weight, they were divided into normal weight group (BMI=18~23.9kg/m2) and overweight group (BMI＞24kg/m2) according to body mass index (BMI). There were 15 participants in each group. After the baseline test, using modified Bruce treadmill protocol, the air metabolism indexes of two groups were determined by Cortex MetaMax 3B portable gas metabolic analyzer, including oxygen uptake(VO2), minute ventilation(MV), breathing frequency(BF), expiratory end-tidal CO2concentration(ETCO2), expiratory end-tidal O2concentration (ETO2), arterial blood carbon dioxide partial pressure (PaCO2), carbon dioxide output(VCO2), oxygen pulse and maximal voluntary ventilation(MMV), etc. The differences of gas metabolism indexes among resting, exercise, and recovery stages were compared and analyzed.&#x0D; Results (1) Most of indexes such as VO2, VCO2, and MV rose gradually with the load increase during exercise stress test except for ETO2and PaCO2. VO2, PaCO2, VCO2and ETCO2of overweight group were significantly lower than normal weight group during the same load. PaCO2of overweight group at grade 4 was significant lower than normal weight group by 5.6 mmHg (P&lt;0.05). VCO2of overweight group at grade 5 was significant lower than normal weight group by 0.6L/min (P&lt;0.05). ETCO2 of overweight group at grade 3 and 4 were significant lower than normal weight group about 0.5% and 0.6% respectively (P&lt;0.05). (2) During recovery stage, most of indexes decreased gradually, such as MV and BF, while ETO2presented a rising trend. At a certain time during the recovery stage, ETCO2of overweight group was significantly lower than normal weight group (5.3% vs 5.8%), while MMV, MV and oxygen pulse were significantly higher than normal weight group (P&lt;0.05). MMV of overweight group at 2, 3 and 4 minutes were significant lower than normal weight group by1L/min, 1L/min and 0.9L/min, at the same time, MV of overweight group were significant lower than normal weight group by17.8L/min, 20.1L/min and 16.9L/min. The oxygen pulse of overweight group during whole 5 minutes recovery period were significantly higher than normal weight group by 2.7L/min, 3.9L/min, 3.9L/min, 2.9L/min and 2.0L/min. (3) The gaseous metabolism between two groups was significantly different when they did 7.1 and 10.2 METs exercise.&#x0D; Conclusions Although there was no difference in gas metabolism between overweight and normal weight adult women in resting state, the respiratory function of overweight women was weaker than normal weight women during exercise, especially at the intensities of 7.1 and 10.2 METs. During the recovery period after exercise stress test, the recovery rate of gas metabolism in overweight adult women was slower than that of normal weight women.