INTRODUCTION: The subject of this study was the creation of a new type of laboratory walking stress test for the Special Forces of the Army of the Czech Republic. This study developed a test model that has been validated in practice and that reflects the fact that the performance of endurance without and with a load varies considerably. Especially, if we focus on operators, as their activities are always performed with loads/full gear (equipment, weapons, equipment, etc.). MATERIALS AND METHODS: 24 men/operators from the Special Forces of the Army of the Czech Republic volunteered for this study. The maximal exercise test/spiroergometry was designed to include performance at a load of 55 kg/121 lb, a constant speed of 5.3 km/h, and an increase in incline angle of 1 degree after each elapsed minute. The test was performed on a treadmill under standard time, location, and temperature conditions. During the test, the following values were recorded: VO2 = oxygen consumption indicating the intensity of the exercise was monitored, VO2/kg = oxygen consumption converted to body weight, VO2/HR = pulse oxygen (the amount of oxygen converted in one heartbeat), HR = heart rate, VE = ventilation, volume of air exhaled in 1 min, breathe frequency (BF) = respiratory rate in 1 min. RESULTS: Out of the total number of 24 respondents, the study found these mean values of variables. The variable mapping the oxygen consumption, which indicates the intensity of VO2 loading, was 3.8, with the lowest value being 3.2 and the highest being 4.5. After converting oxygen consumption to bodyweight, VO2/kg was 46, the lowest value of 38.8, and the highest 53.0 were measured for this variable. Pulse oxygen, i.e., the amount of oxygen calculated per heart contraction VO2/HR, was 20.5, the lowest value 16.0, and the highest 26.0. The average HR heart rate was 183.5, with the lowest value being recorded at 164 and the highest value is 205. Ventilation, i.e., the amount of exhaled air per minute in VE, was measured at 144.9, the lowest value was 114.7, and the highest was 176.6. The BF in 1 min was 58.5, the lowest value 35, and the highest 70. The mean time load was 10:20 min, the shortest test length was 7:25 min, and the longest was 13:23 min. These values correspond to the degree of inclination of the ascent, i.e., the mean value was 10 degrees, the smallest achieved slope was 7 degrees, and the largest 13 degrees. CONCLUSION: The designed weighted walking test proved to be fully functional and effective in measurement. The further established protocol corresponds to the requirements of the current needs of the Special Forces of the Army of the Czech Republic. Last but not least, the walking stress test is applied for the external and internal selection and screening of operators. Data obtained from testing were used to develop deployment requirements for patrol/nuclear combat missions.
- MeSH
- chůze MeSH
- cvičení * fyziologie MeSH
- kyslík MeSH
- lidé MeSH
- spotřeba kyslíku * fyziologie MeSH
- srdeční frekvence MeSH
- zátěžový test MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Stroke volume (SV), heart rate (HR) and arterio-venous O2 difference (a-vO2diff) responses to heavy and severe-intensity exercise have been well documented; however, there is a lack of information on the SV, HR and a v-O2diff responses of work rates within extreme exercise domain. The aim of this study was, therefore, to focus on central and peripheral components of VO2 responses to exercises performed within the heavy, severe and extreme exercise domain. Eight well-trained male cyclists participated in this study. Maximal O2 consumption (VO2max) and corresponding work rate (P@VO2max) were determined by multisession constant work rate exercises. Cardiovascular responses to exercises were evaluated by nitrous-oxide rebreathing method with work rates from 40 % to 160 % of P@VO2max, VO2max corresponded to 324+/-39.4 W; however, maximal SV responses occurred at 205+/-54.3 W (p<0.01). Maximal cardiac output (Q), HR, and a vO2diff responses were revealed by the P@VO2max. VO2 response to exercise significantly decreased from severe-intense exercises to the first work rate of extreme exercise domain due to significant decreases in Q, SV, and HR responses (p<0.05), except a v-O2diff (p>0.05). Moreover, non-significant decreases in Q, SV, and a v-O2diff were evaluated as response to increase in work rate belonging to extreme work rates (p>0.05), except the HR (p<0.05). Work rates within the lower district of the extreme exercise domain have an important potential to improve peripheral component of VO2, while the P@VO2max seems the most appropriate intensity for aerobic endurance development as it maximizes the central component of VO2max.
BACKGROUND: COVID-19 survivors may experience long-term health problems, including deterioration of cardiorespiratory fitness (CRF), as demonstrated by several cross-sectional studies that compared the results of cardiopulmonary exercise tests (CPET) performed only after COVID-19 with predicted values. This study aimed to analyze a change in CRF between repeated CPETs in response to suffered COVID-19. METHODS: A total of 127 healthcare workers (HCWs; mean age 55.7 years) underwent two CPETs with a mean interval of 762 days. Forty HCWs suffered from COVID-19 (mild to moderate severity) in the interim (321 days before the second CPET), and 87 HCWs formed a control group. Mixed-effects regression with multiple adjustment and interaction terms was used for two response variables - maximum oxygen uptake (VO2 max) and power output. RESULTS: Between both CPETs, mean VO2 max decreased statistically significantly in the COVID-19 subgroup (by 3.12 mL/kg/min, p = .034) and insignificantly in controls (by 0.56 mL/kg/min, p = .412). The proportion of HCWs achieving predicted VO2 max decreased from 75.9% to 59.5% (p = .161) in COVID-19 survivors, while it increased from 73.8% to 81% (p = .274) in controls. COVID-19 (β = -0.66, p = .014) and body mass index (β = -0.49, p < .001) were independent negative predictors of VO2 max change. COVID-19 was not associated with a change in power output. CONCLUSIONS: On the basis of repeated CPETs, COVID-19 significantly, albeit rather modestly, reduces CRF almost one year after infection. The reduction persists even after the acute phase with mild or moderate severity.
The objectives of this study were to investigate the reliability, validity, and usefulness of the 30-15 intermittent fitness test (30-15IFT) in soldiers. The 34 infantry members of the Slovenian armed forces were recruited as participants. Participants performed the continuous incremental treadmill test (TR), a 2-mile run (2MR) test, and two 30-15IFT tests. Additionally, participants were divided into a highest-scoring group (HSG) and a lowest-scoring group (LSG) based on their scores on the Army Physical Fitness Test. A very high reliability ratings were observed for 30-15IFT measures, as follows: end-running speed (ERS) ERSIFT (ICC = 0.971), maximal heart rate (HRmax) HRmaxIFT (IC = 0.960), and maximal relative oxygen consumption (VO2max) VO2max-IFT (ICC = 0.975). Although 30-15IFT measures demonstrated high correlations (r = 0.695-0.930) to the same measures of TR test, ERS, HRmax and VO2max were higher in the 30-15IFT (p > 0.05). Furthermore, ERSIFT and predicted VO2maxIFT were higher in HSG compared to LSG, whereas HRmax did not differ. The results of this study show that the 30-15IFT test is a reliable, valid and useful tool for assessing cardiorespiratory fitness in the armed forces. Moreover, the ERS and predicted VO2max values derived from the 30-15IFT could be considered more sensitive markers of combat readiness than the parameters derived from the TR and 2MR tests.Trial registration number: NCT05218798.
- MeSH
- kardiorespirační zdatnost * fyziologie MeSH
- lidé MeSH
- ozbrojené síly * MeSH
- reprodukovatelnost výsledků MeSH
- spotřeba kyslíku fyziologie MeSH
- srdeční frekvence fyziologie MeSH
- tělesná výkonnost fyziologie MeSH
- zátěžový test metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- klinická studie MeSH
The aim of the present study was to investigate whether the physiological parameters indicative of cardiorespiratory fitness obtained during the 30-15 intermittent fitness (30-15IFT) test and the multistage laboratory treadmill endurance (TR) test differ. Nineteen elite handball players were recruited for the current study and assigned in a cross-over manner to one of two tests to be performed 48 h apart at each visit to the testing facility. The results showed that VO2max (percentage difference [PC] = 6.1%; p = 0.004) and maximal running velocity (V) (PC = 19.4%; p < 0.001) were significantly higher for the 30-15IFT test than that obtained during the TR test. Furthermore, the onset of blood lactate accumulation was shown to be significantly higher for all measures considered to predict it during 30-15IFT compared to TR as follows: VO2max (PC = 12.6%; p = 0.001), running speed (PC = 33.9%; p < 0.001), and maximal heart rate (PC = 7.5%; p < 0.001). The current study highlights the importance of sport-specific testing, particularly for measuring individual cardiorespiratory fitness in elite handball players, as TR may underestimate crucial variables used for both diagnostics and training prescription.
Mitochondria are considered central regulator of the aging process; however, majority of studies dealing with the impact of age on mitochondrial oxygen consumption focused on skeletal muscle concluding (although not uniformly) a general declining trend with advancing age. In addition, gender related differences in mitochondrial respiration have not been satisfactorily described yet. The aim of the present study was to evaluate mitochondrial oxygen consumption in various organs of aging male and female Fischer 344 rats at the ages of 6, 12 and 24 months. Mitochondrial respiration of homogenized (skeletal muscle, left and right heart ventricle, hippocampus, cerebellum, kidney cortex), gently mechanically permeabilized (liver) tissue or intact cells (platelets) was determined using high-resolution respirometry (oxygraphs O2k, Oroboros, Austria). The pattern of age-related changes differed in each tissue: in the skeletal muscle and kidney cortex of both sexes and in female heart, parameters of mitochondrial respiration significantly declined with age. Resting respiration of intact platelets displayed an increasing trend and it did not correlate with skeletal muscle respiratory states. In the heart of male rats and brain tissues of both sexes, respiratory states remained relatively stable over analyzed age categories with few exceptions of lower mitochondrial oxygen consumption at the age of 24 months. In the liver, OXPHOS capacity was higher in females than in males with either no difference between the ages of 6 and 24 months or even significant increase at the age of 24 months in the male rats. In conclusion, the results of our study indicate that the concept of general pattern of age-dependent decline in mitochondrial oxygen consumption across different organs and tissues could be misleading. Also, the statement of higher mitochondrial respiration in females seems to be conflicting, since the gender-related differences may vary with the tissue studied, combination of substrates used and might be better detectable at younger ages than in old animals.
- MeSH
- anestezie MeSH
- buněčné dýchání MeSH
- dýchání MeSH
- kosterní svaly metabolismus MeSH
- krysa rodu rattus MeSH
- mitochondrie * MeSH
- spotřeba kyslíku fyziologie MeSH
- stárnutí MeSH
- svalové mitochondrie * metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Measurement of oxygen consumption of cultured cells is widely used for diagnosis of mitochondrial diseases, drug testing, biotechnology, and toxicology. Fibroblasts are cultured in monolayers, but physiological measurements are carried out in suspended or attached cells. We address the question whether respiration differs in attached versus suspended cells using multiwell respirometry (Agilent Seahorse XF24) and high-resolution respirometry (Oroboros O2k), respectively. Respiration of human dermal fibroblasts measured in culture medium was baseline-corrected for residual oxygen consumption and expressed as oxygen flow per cell. No differences were observed between attached and suspended cells in ROUTINE respiration of living cells and LEAK respiration obtained after inhibition of ATP synthase by oligomycin. The electron transfer capacity was higher in the O2k than in the XF24. This could be explained by a limitation to two uncoupler titrations in the XF24 which led to an underestimation compared to multiple titration steps in the O2k. A quantitative evaluation of respiration measured via different platforms revealed that short-term suspension of fibroblasts did not affect respiratory activity and coupling control. Evaluation of results obtained by different platforms provides a test for reproducibility beyond repeatability. Repeatability and reproducibility are required for building a validated respirometric database.
ABSTRACT: Marko, D, Bahenský, P, Snarr, RL, and Malátová, R. V̇ o2 peak Comparison of a treadmill vs. cycling protocol in elite teenage competitive runners, cyclists, and swimmers. J Strength Cond Res 36(10): 2875-2882, 2022-The purpose of this study was to compare the cardiorespiratory and metabolic responses of a maximal graded exercise test (GXT) on a treadmill and cycle ergometer in elite-level, youth competitive athletes. Thirty-one athletes (11 distance runners, 11 mountain-bike cyclists, and 9 long-distance swimmers) were randomly selected to complete either a running or cycling GXT on the first day, followed by the alternative 72 hours apart. The initial work rate for each GXT was set at 50% of the individuals' previously established V̇ o2 peak to elicit fatigue within 8-12 minutes. For the treadmill protocol, speed was increased by 1 km·h -1 each minute, with a constant 5% grade, until volitional fatigue. Cycle ergometer work rate was increased by 30 W every minute until volitional fatigue or the inability to maintain proper cadence (i.e., 100 ± 5 rev·min -1 ). Throughout both testing sessions, V̇ o2 peak, heart rate [HR] peak, breathing frequency (BF), tidal volume (V T ), and minute ventilation (V E ) were assessed and used to compare within-sport differences. Runners displayed a higher V̇ o2 peak (∼7%; d = 0.92), HRpeak (4%; d = 0.77), V E (6%; d = 0.66), and BF (12%; d = 0.62) on the treadmill vs. cycle. However, the cycling group demonstrated a greater V̇ o2 peak (∼8%; d = 0.92), V T (∼14%; d = 0.99), and V E (∼9%; d = 0.78) on the cycle, despite no change in HRpeak. For swimmers, the treadmill GXT elicited higher values in V̇ o2 peak (∼5%; d = 0.75), BF (∼11.5%; d = 0.78), and HRpeak (3%; d = 0.69). Collectively, these findings indicate that exercise mode may greatly affect physiological outcome variables and should be considered before exercise prescription and athletic monitoring.
- MeSH
- běh * fyziologie MeSH
- cyklistika fyziologie MeSH
- lidé MeSH
- mladiství MeSH
- spotřeba kyslíku fyziologie MeSH
- srdeční frekvence fyziologie MeSH
- únava MeSH
- zátěžový test * metody MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- Publikační typ
- časopisecké články MeSH
BACKROUND: The purpose of this study was to examine the effects of soccer training on maximal oxygen uptake and anthropometric characteristics in different ages of soccer players and untrained adolescents of the same biological age. METHODS: A total of one hundred and twenty-six (N.=126) young soccer players and untrained boys throughout the developmental ages of 12 (soccer players N.=22; untrained boys = 22) 14 (soccer players N.=20; untrained boys = 18) and 16 (soccer players N.=22; untrained boys = 22) volunteered to participate in the study. Sexual maturation was classified according to Tanner's stages. Soccer players participated both in their school's physical education program and in a soccer training program, while the untrained participated only in their school's physical education program. All participants underwent anthropometric measurements and performed a maximal exercise test on a motor driven treadmill to determine maximal oxygen uptake (V̇O2
- MeSH
- antropometrie MeSH
- cvičení fyziologie MeSH
- fotbal fyziologie MeSH
- krevní tlak MeSH
- lidé MeSH
- mladiství MeSH
- respirační funkční testy MeSH
- spotřeba kyslíku fyziologie MeSH
- stárnutí MeSH
- tělesná výchova MeSH
- tolerance zátěže fyziologie MeSH
- zátěžový test metody MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Klíčová slova
- segment ST,
- MeSH
- bezpečnost MeSH
- diagnostické techniky kardiovaskulární MeSH
- ergometrie * metody přístrojové vybavení MeSH
- ischemická choroba srdeční prevence a kontrola MeSH
- kontraindikace MeSH
- lidé MeSH
- metabolický ekvivalent MeSH
- riziko MeSH
- spotřeba kyslíku fyziologie MeSH
- zátěžový test MeSH
- Check Tag
- lidé MeSH
