Determination Of Anaerobic Threshold Research Articles

Određivanje anaerobnog praga direktnim merenjem laktata u krvi bez protokola zagrevanja kod sportistkinja

Introduction: The anaerobic threshold (AT), determined by the direct blood lactate measurement, is of huge practical significance during the training test with the aim to estimate the training status of the female athletes. Aim: The aim of this research was to determine anaerobic threshold by direct blood lactate. Material and Methods: Academic research included 20 female subjects divided into four groups: I group - 10 non-trained subjects, who were not previously subjected to the warm up protocol, II group - 10 well-trained subjects who were not previously subjected to the warm up protocol of Conconi test. Results: Results obtained and presented in this paper show that AT, determined by the direct blood lactate measurement, is statistically significant (p < 0,001) in higher values of the heart rate in well-trained subjects compared to the non-trained subjects not subjected. Conclusion: According to the aforementioned authors the Conconi test can be used nonetheless because of its easy administration with the precondition to provide the adequate interpretation in the assessment of the training capability in all sports activities.

Comparison between determination of second anaerobic threshold by respiratory compensating point and X-method in rowers

Background and Study Aim. The aim of this study is to verify the X-method for determining the second anaerobic threshold in rowers.Material and Methods. Twelve male athletes from the national rowing team of Bulgaria were tested. Participants performed a one-time graded incremental exercise test to exhaustion on a rowing ergometer. The workload were conducted on rowing ergometer system Concept 2, and spirometry system Clark C5. We obtained ventilatory indices, intensity and heart rate bred-by-bred for each participant, for each test stage. The anaerobic threshold was determined by two methods: 1) by the localization of the respiratory compensation point visually, after polynomial regression analysis of the trends for the dynamics of the ventilatory variables related to time and 2) by the X-method using the change in the ratio between heart rate and pulmonary ventilation. We compared the heart rate corresponding to the anaerobic threshold determined by both methods.Results. We found similar values for heart rate at the respiratory compensation point and the anaerobic threshold determined by the X-method for each of the investigated. The Shapiro-Wilk test showed a normal distribution of the two samples with a significance level of α = 0.05. Thus, the t-test for two paired samples showed a p-value of 0.202 at α = 0.05. We found a correlation coefficient r = 0.973 between the heart rate at the anaerobic threshold (determined by X-method) and the heart rate at the anaerobic threshold (detected at the respiratory compensation point). The Blant-Altman analysis showed that 95% of the points in the scatter plot lie within the confidence interval.Conclusions. The two methods give similar results and can be applied alternatively in the investigation of rowers in the age group 18.3 ± 1.07 years. The X-method always gives a reliable intersection point, which in our studies is close to the second anaerobic threshold. Comparative studies are also needed in other contingents for the wider use of the X-method.

The Impact of Grounding in Running Shoes on Indices of Performance in Elite Competitive Athletes.

The introduction of carbon fiber plate shoes has triggered a plethora of world records in running, which has encouraged shoe industries to produce novel shoe designs to enhance running performance, including shoes containing conductor elements or “grounding shoes” (GS), which could potentially reduce the energy cost of running. The aim of this study was to examine the physiological and perceptual responses of athletes subjected to grounding shoes during running. Ten elite runners were recruited. Firstly, the athletes performed an incremental running test for VO2max and anaerobic threshold (AT) determination, and were familiarized with the two shoe conditions (traditional training shoe (TTS) and GS, the latter containing a conductor element under the insole). One week apart, athletes performed running economy tests (20 min run at 80% of the AT) on a 400 m dirt track, with shoe conditions randomized. VO2, heart rate, lactate, and perceived fatigue were registered throughout the experiment. No differences in any of the physiological or perceptual variables were identified between shoe conditions, with an equal running economy in both TTS and GS (51.1 ± 4.2 vs. 50.9 ± 5.1 mL kg−1 min−1, respectively). Our results suggest that a grounding stimulus does not improve the energy cost of running, or the physiological/perceptual responses of elite athletes.

Determination of the athletes' anaerobic threshold using machine learning methods

Physiological indicators at the anaerobic threshold (AT) are an important diagnostic criterion for determining the level of an athlete's fitness and one of the starting points for planning and adjusting the training process. To develop the model for determining athletes' AT, the results of 1273 observations of athletes aged 18–35 years were processed. Athletes performed a stepwise cardiopulmonary exercising test (CPET) on the treadmill to failure. Linear Regression, Random Forest Regression, Gradient Boosting, and Support Vector Regression (SVR) from the Scikit-learn library were used to determine the physiological parameters of energy supply at the AT. The best quality metrics for determining the AT were obtained by SVR, where the coefficient of determination for heart rate (HR), respiratory minute volume (V'E), oxygen consumption (VO2), emission of carbon dioxide (VCO2), oxygen pulse (O2/HR) was 0.82, 0.90, 0.87, 0.86, and 0.91, respectively. The special significance of the obtained model lies in the fact that it can be used to identify indicators and their quantitative values that limit the further development of the AT-based technique to plan and correct a training process. This feature was provided by the Local Interpretable Model-agnostic Explanations (LIME). LIME was used to explain the prediction of the developed model in an interpreted and accurate way by studying the model locally around the prediction. The developed model for determining the AT opens up new opportunities in the interpretation of CPET, will allow researchers to identify individual patterns that affect the test result, and, consequently, give more accurate recommendations for correcting the athletes' training process.

EMG breakpoints for detecting anaerobic threshold and respiratory compensation point in recovered COVID-19 patients

IntroductionA huge number of COVID-19 patients should be referred to rehabilitation programmes. Individualizing the exercise intensity by metabolic response provide good physiological results. The aim of this study was to investigate the validity of EMG as a non-invasive determinant of the anaerobic threshold and respiratory compensation point, for more precise exercise intensity prescription. MethodsAn observational cross-sectional study with 66 recovered COVID-19 patients was carried out. The patients underwent a cardiopulmonary exercise test with simultaneous assessment of muscle electromyography in vastus lateralis. EMG breakpoints were analyzed during the ramp-up protocol. The first and second EMG breakpoints were used for anaerobic threshold and respiratory compensation point determination. ResultsEMG and gas exchange analysis presented strong correlation in anaerobic threshold (r = 0.97, p < 0.0001) and respiratory compensation point detection (r = 0.99, p < 0.0001) detection. Bland-Altman analysis demonstrated a bias = −4.7 W (SD = 6.2 W, limits of agreement = −16.9 to 7.6) for anaerobic threshold detection in EMG compared to gas exchange analysis. In respiratory compensation point detection, Bland-Altman analysis demonstrated a bias = -2.1 W (SD = 4.5 W, limits of agreement = −10.9 to 6.6) in EMG compared to gas exchange analysis. EMG demonstrated a small effect size compared to gas exchange analysis in oxygen uptake and power output at anaerobic threshold and respiratory compensation point detection. ConclusionsEMG analysis detects anaerobic threshold and respiratory compensation point without clinical significant difference than gas exchange analysis (gold standard method) in recovered COVID-19 patients.

Muscle oxygenation assessment during talk test to determine the anaerobic threshold in individuals with cardiovascular disease

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. Background Cardiopulmonary exercise test (CPET) is the reference method for assessing gas exchange threshold (GET), a surrogate of the anaerobic threshold (AnT). However, muscle oxygenation has been shown as an additional tool for AnT determination, using the lower limb threshold (LLT). Besides, Talk Test (TT), a tool used to assess, prescribe, and monitor exercise intensity through speech comfort level, has shown a correlation with GET as well. Purpose To identify the AnT obtained from the traditional method from CPET (GET) and the LLT; to compare heart rate (HR) and tissue saturation index (TSI) data at AnT (GET and LLT); to compare the parameters of LLT on CPET and TT, and to correlate LLT and TT stages in cardiovascular disease (CVD) patients. Methods CVD patients underwent CPET and TT, both on a treadmill, in two distinctive days. During those tests, peripheral muscle oxygenation was assessed by the near-infrared spectroscopy method. GET (CPET) was determined by the V-slope method; LLT (CPET and TT) was determined by the visual inspection of oxyhemoglobin and deoxyhemoglobin curves. A TT protocol based on the prediction equation for the covered distance of the six-minute walk test (6MWD) was applied. TT protocol was incremental, with two-minutes stages starting at 70% of the average velocity predicted and 2% of inclination, increasing velocity in 10 percentage points (p.p.) at each stage, until the fifth stage, at which the inclination was increased in 2 p.p. until test completion. At the end of each stage, patients read a standardized paragraph and were asked about speech comfort. Shapiro-Wilk test was performed to assess data distribution. Wilcoxon test was applied to compare physiological variables (HR and TSI) at GET and LLT. Repeated measures analysis of variance (ANOVA), followed by Bonferroni post-hoc test was assessed to compare the variables at LLT and TT stages (last TT+ and first TT±). Spearman correlation coefficient was used to assess the relationship between variables. Statistical significance was set at 5%. Results 24 cardiovascular patients were included. Similar values of HR (GET vs. LLT: 102 ± 15 bpm vs. 99 ± 14 bpm, p = 0,08), and TSI (GET vs. LLT: 64,6 ± 8,2% vs. 66,4 ± 7,8%, p = 0,09) were observed during CPET. Regarding LLT at CPET and TT, there was no difference between HR (CPET vs. TT: 99 ± 14 bpm vs. 100 ± 12 bpm, p = 1,00) and TSI (CPET vs. TT: 66,4 ± 7,8% vs. 65,3 ± 4,9%, p = 1,00). Furthermore, good relationship between HR in LLT and TT stages (LLT vs. TT+: r = 0,79; LLT vs. TT±: r = 0,76; p &amp;lt; 0,05 for both) was found. Conclusions Our results showed similarity between LLT and GET. Besides, TT showed a similar response of muscle oxygenation and heart rate comparing to CPET, with a good correlation between LLT and TT stages. These results endorse the validity of TT as an auxiliary and low-cost tool to identify the AnT.

Determination of Anaerobic Threshold by a new approach through the incremental exercise using proportion in HR and Ve changes in rowers

Background and Study Aim. The aim of this research is to create a non-invasive and easy to apply in practice approach to determine the anaerobic threshold based only on measurement of the pulmonary ventilation and the hearth rate. It uses proportions, with which these variables were changed during a maximal incremental test.&#x0D; Material and Methods. Twenty athletes from the national rowing team of Bulgaria with average age of 17.5 years were tested. Participants performed a one-time graded incremental exercise test to exhaustion on a rowing ergometer. The proposed new approach for determining the anaerobic threshold is related to detecting the power. Thus, one curve (obtained from differences in percentages of hearth rate and pulmonary ventilation) crosses the other one (obtained from pulmonary ventilation in percentages). The crossing point corresponds to the anaerobic threshold. This approach was compared with two methods determining the lactate threshold, by blood lactate measurement.&#x0D; Results. The Shapiro-Wilk test results indicated, that the samples of the heart rate of the compared methods have a normal or close to the normal distribution. The Fisher's F-test demonstrated, that the standard deviations of the samples do not differ significantly two by two at ɑ=0.05. The Bland&amp;Altman test presented, that the 95% of all measurement data points lie within the confidence interval limit for each of the comparisons made between the new approach and two methods.&#x0D; Conclusions. Our proposed approach is non-invasive and can be easily applied in the field conditions, without using gas-analysing devices. In addition, it is reliable, reproducible and comparable to the accepted for “Gold Standard” methods for determination of anaerobic threshold with 95% statistical significance.

Anaerobic Threshold Prediction Using the OMNI-Walk/Run Scale in Long-Distance Runners: A Preliminary Study.

To identify the anaerobic threshold through the lactate threshold determined by Dmax and rating of perceived exertion (RPE) threshold by Dmax and to evaluate the agreement and correlation between lactate threshold determined by Dmax and RPE threshold by Dmax during an incremental test performed on the treadmill in long-distance runners. A total of 16 long-distance runners volunteered to participate in the study. Participants performed 2 treadmill incremental tests for the collection of blood lactate concentrations and RPE separated by a 48-hour interval. The incremental test started at 8km·h-1, increasing by 1.2km·h-1 every third minute until exhaustion. During each stage of the incremental test, there were pauses of 30 seconds for the collection of blood lactate concentration and RPE. No significant difference was found between methods lactate threshold determined by Dmax and RPE threshold by Dmax methods (P = .664). In addition, a strong correlation (r = .91) and agreement through Bland-Altman plot analysis were found. The study demonstrated that it is possible to predict anaerobic threshold from the OMNI-walk/run scale curve through a single incremental test on the treadmill. However, further studies are needed to evaluate the reproducibility and objectivity of the OMNI-walk/run scale for anaerobic threshold determination.

Effects of preferred music on physiological responses, perceived exertion, and anaerobic threshold determination in an incremental running test on both sexes.

This study aimed to investigate and compare the effects of preferred music on anaerobic threshold determination in an incremental running test, as well the physiological responses and perceived exertion at this intensity, in physically active men and women. Additionally, by using area under the curve (AUC) analysis of the parameters of interest during the graded test, we studied the effects of music at two physiological moments—before and after anaerobic threshold intensity (iAT)—in men and women. Twenty (men = 10; women = 10) healthy and active participants completed four visits to the laboratory. The first and second sessions were used for sample characterization. In the third and fourth sessions, participants performed an incremental running test (started at 7 km.h-1 with increments of 1 km.h-1 at each 3-minute stage) under preferred music and non-music conditions. Blood lactate ([Lac]), heart rate (HR), and perceived exertion were measured by two scales (RPEBorg and the estimation of time limit ‒ ETL) during all tests, and the total time of effort (TT) was considered as performance. Individual curves of the “intensity vs blood lactate” analyzed by the bissegmentation method provide the iAT and the AUC of [Lac], HR, RPEBorg, and ETL before and after the iAT attainment were calculated. The iAT for men (non-music: 11.5±0.9km.h-1 vs music: 11.6±1.1km.h-1) and women (non-music: 9.8±0.7km.h-1 vs music: 9.7±0.7km.h-1) was not affected by music, and for both sexes, there was no difference between non-music and music conditions in all variables obtained at iAT. The AUC of all variables were not affected by music before the iAT attainment. However, [Lac], HR, and RPEBorg presented higher values of AUC after iAT for the female group with preferred music. This may be due to the fact that 70% of women have increased TT under music conditions. Overall, preferred music did not affect the iAT determination in an incremental running test. However, some physiological responses and perceived exertion after iAT of female subjects seems to be influenced by preferred music.

Chronotropic Intolerance In Patients With Chronic Lyme Disease Identified By Serial Cardiopulmonary Exercise Testing

In the U.S., annual incidence of Lyme disease is approximately 300,000. In an estimated 5-30% of cases, post-treatment Lyme disease syndrome (PTLDS) develops; symptoms include post-exertional malaise characteristic of myalgic encephalomyelitis. The contribution of autonomic regulation has not been elucidated. PURPOSE: To evaluate cardiovascular responses to serial cardiopulmonary testing in patients with PTLDS. METHODS: 14 patients with PTLDS and 8 sedentary controls underwent 2 maximal exercise tests separated by 24 hours. Heart rate (HR) was measured continuously via electrocardiogram. Expired air was collected for determination of anaerobic threshold (AT) using V-slope methodology and maximal exertion was defined as a respiratory exchange ratio >1.09. Independent-samples t-tests compared baseline characteristics of PTLDS patients and controls. Linear regression determined the effect of PTLDS diagnosis on HR at AT and peak holding workload constant. RESULTS: Patients were 44.0±10.1 years old, weighed 69.8±16.2 kg, and achieved a peak VO2 of 23.8±6.2 mL/kg/min during test 1. HR was 116.2±21.8 bpm at AT and 162.6±25.1 at peak. PTLDS and controls did not differ in peak VO2 during test 1 (p=0.161), test 2 (p=0.134), or the difference between test 1 and test 2 (p=0.498). HR at AT was comparable in test 1 (p=0.127) but different in test 2 (p<0.001). HR at peak was different in test 1 (p=0.001) and test 2 (p<0.001). During test 1, holding workload constant, PTLDS patients had lower peak HR by 19.5 bpm (p=0.033; 95% CI: -37.3 to -1.8). During test 2, holding workload constant, PTLDS predicted a lower HR by 26.8 bpm at AT (p=0.004; 95% CI: -43.9 to -9.8) and 24.3 bpm at peak (p=0.007; 95% CI: -40.9±-7.7). CONCLUSIONS: Patients with PTLDS demonstrated abnormal cardiovascular responses to exercise. Despite accomplishing the same VO2, and holding workload constant, the HR response was diminished in the post-exertional state, potentially indicating dysautonomia in PTLDS.

Anaerobic Threshold Determination in Cycle Ergometer From Rating of Perceived Exertion.

Santos, GAd, Numata-Filho, ES, Rosa, TdS, Passos Neves, RV, Simões, HG, and Moreira, SR. Anaerobic threshold determination in cycle ergometer from rating of perceived exertion. J Strength Cond Res 36(5): 1277-1281, 2022-The objective of the study was to investigate the validity of the rating of perceived exertion threshold (TRPE) for anaerobic threshold (AT) estimation during an incremental test (IT) on a cycle ergometer. Nineteen physically active and healthy men performed an IT on a cycle ergometer. The intensity corresponding to the AT was considered as the point immediately before the abrupt increase in blood lactate concentration ([La]) in the IT. TRPE was determined in the last intensity corresponding to perceptual response previous the 15 arbitrary units (AU) in the 15-point RPE scale. The heart rate (HR), [La], and RPE were obtained at the end of each stage of the IT. There was no significant difference between workload obtained from the AT (150 [120-150] watts) and TRPE (150 [120-150] watts) (p > 0.05). In addition, there were no differences between HR (AT, 139.5 ± 12.7 b·min-1 vs. TRPE, 141.9 ± 14.6 b·min-1, p > 0.05) and [La] (AT, 3.1 [2.8-3.2] mM vs. TRPE, 3.1 [2.9-3.7] mM, p > 0.05). There was a strong correlation between the intensities in AT and TRPE during the IT (r = 0.88). A substantial reliability (intraclass correlation coefficient = 0.84 [0.64-0.94 confidence interval 95%]) was evidenced, as well as a substantial agreement between the AT and TRPE intensities (Pc = 0.84), as confirmed by the Bland-Altman plot (-4.7 [-34.2/24.7]). TRPE was a predictor of the AT (β = 1.146, R = 0.770, SEE = 15.070, p < 0.01). It can be concluded that TRPE is valid for AT estimation during an IT on a cycle ergometer.

Diagnostic role of cardiopulmonary exercise testing in patients with sarcoidosis

A review of protocols and staging of cardiopulmonary exercise testing (CPET) used in clinical practice is done in the article. CPET is proposed to assess the functional status and to diagnose early reserve abnormalities in patients with sarcoidosis as far as functional tests at rest are mostly insufficient in sarcoidosis. Physiological processes at anaerobic threshold at peak exercise are described in the article. The authors reviewed current approach to terminology and determination of anaerobic threshold, methods for calculation of cut-off points and their clinical role. Diagnostic values of CPET parameters, such as maximal and peak oxygen uptake and oxygen consumption ratio, parameters of gas exchange and ventilation, such as ventilatory equivalent, breathing reserve, alveolar-arterial gradient in oxygen, and ventilation-perfusion ratio, in patients with sarcoidosis were also discussed.

Determination of Anaerobic Threshold by Monitoring the O2 Pulse Changes in Endurance Cyclists.

The purpose of this study was to determine the validity of anaerobic threshold (AnT)-equivalent to the second turn point for lactate (LTP2)-estimation using the O2 pulse changes in highly trained endurance cyclists who do not show heart rate deflection point (HRDP) during incremental testing. Sixteen endurance cyclists (age, 24.8 ± 4.7 years) and fifteen active men (age, 24.8 ± 3.7 years) performed an incremental cycling test to exhaustion. Pulmonary oxygen uptake (V[Combining Dot Above]O2) and other hemodynamic variables, heart rate, and blood lactate concentration were measured continuously throughout the test. O2 pulse anaerobic threshold (O2 pulse-AnT) was defined as the second turn point in O2 pulse-workload curve. LTP2 was considered as gold standard assessment of AnT and was applied to confirm the validity of O2 pulse-AnT. Intraclass correlation coefficients and the Bland-Altman method were used to determine the relationship and agreement between the O2 corresponding to LTP2 and O2 pulse-AnT, respectively. The active men and 68.7% of the endurance cyclists showed HRDP, whereas all subjects showed O2 pulse-AnT during incremental testing. In both groups, the values for V[Combining Dot Above]O2 corresponding to LTP2 were not significantly different from the V[Combining Dot Above]O2 at O2 pulse-AnT. The V[Combining Dot Above]O2 at LTP2 and O2 pulse-AnT were highly correlated (endurance cyclists: R = 0.68; standard error of estimate [SEE] = 3.74 ml·kg·min and active men: R = 0.58; SEE = 2.91 ml·kg·min) and Bland-Altman plot revealed the limit of agreement of O2 at LTP2 and O2 pulse-AnT differences between 5.1 and 8.6 ml·kg·min (95% CI). In summary, results of this study showed that the second turn point in the O2 pulse-workload curve occurs around LTP2. Therefore, using O2 pulse-AnT is recommended for the noninvasive determination of AnT in highly trained endurance cyclists who do not show HRDP during incremental exercise.

The correlations between commonly used anaerobic threshold determination methods

The correlations between commonly used anaerobic threshold determination methods

Determination of anaerobic threshold through heart rate and near infrared spectroscopy in elderly healthy men

Aging leads to low functional capacity and this can be reversed by safe and adequate exercise prescription. The aim of this study was to identify the anaerobic threshold (AT) obtained from the V-slope method as well as visual inspection of oxyhemoglobin ( O2Hb) and deoxyhemoglobin (HHb) curves and compare findings with the heteroscedastic (HS) method applied to carbon dioxide production ( CO2), heart rate (HR), and HHb data in healthy elderly men. A secondary aim was to assess the degree of agreement between methods for AT determination. Fourteen healthy men (61.4±6.3 years) underwent cardiopulmonary exercise testing (CPX) on a cycle ergometer until physical exhaustion. Biological signals collected during CPX included: ventilatory and metabolic variables; spectroscopy quasi-infrared rays - NIRS; and HR through a cardio-frequency meter. We observed temporal equivalence and similar values of power (W), absolute oxygen consumption (O2 - mL/min), relative O2 ( mL.Kg - 1.min -1), and HR at AT by the detection methods performed. In addition, by the Bland-Altman plot, HR confirmed good agreement between the methods with biases between -1.3 and 3.5 beats per minute. (i) all detection methods were sensitive in identifying AT, including the HS applied to HR and (ii) the methods showed a good correlation in the identification of AT. Thus, these results support HR as valid and readily available parameter in determining AT in healthy elderly men.

Diversity of anaerobic and respiratory threshold determination methods

Diversity of anaerobic and respiratory threshold determination methods

Effect of five-week preparatory training period on aerobic and anaerobic performance of male judo athletes

Summary Introduction. The physiological demands of a judo match strain both anaerobic and aerobic systems. The purpose of the present study was to examine the effect of five weeks of training during a preparatory period on anaerobic and aerobic performance of well trained male judokas. Material and methods. The subject of the present study were nine male judo athletes, members of a collegiate team. Before and after five-week training, all participants performed a graded exercise test on the treadmill for the determination of anaerobic threshold and the 30 s Wingate test for lower body. After each workload, the capillary blood from finger tips was taken for lactate determination during incremental exercise and 5, 7, 9, 11, 13, and 30 minutes after cessation of the 30 s Wingate test. Results. Five-week training period resulted in statistically significant increase of velocity at anaerobic threshold (VAT), determined in a graded exercise test. The peak power, in terms of relative (W/kg) values, measured in the Wingate test for lower body, was similar before and after the five-week training period, however the relative mean power was significantly higher after this training period finished. The blood lactate concentration, 30 minutes after cessation of the Wingate test, was significantly lower after the five weeks of training in comparison with the values before training. Conclusions. The obtained data shows that the five-week preparatory training period resulted in the increase of aerobic fitness of male judo athletes. The results of the current study in well trained male judokas may provide useful information for coaches and trainers in optimizing training programs.

A new approach for the determination of anaerobic threshold: methodological survey on the modified Dmax method

A wide variety of diagnostic techniques can be found in the literature for anaerobic threshold (AT) assessment. The aim of this study was to investigate if the heart rate (HR) at the modified D max method (Mod-D max ) using parallel straight line slope (PSLS) mathematical model and the Narita target heart rate equation was comparable with the HR measured at the AT by the continuous respiratory gas measurements in healthy young girls. Eight (age 19.29±1.70 years) healthy young girls performed an exhaustive treadmill exercise test for determination of the HR at Mod-D max using PSLS model and Narita equation. The AT of the participants was also calculated by the continuous respiratory gas measurements according to the Craig method. There was no significant difference between the HR determined at the Mod-D max method and the HR measured at the AT by the continuous respiratory gas measurements (167±9.22 vs. 165.25±6.32 b/min). Bland and Altman plots revealed a good agreement between the determined HR at Mod-D max and values of the HR measured at the AT by the continuous respiratory gas measurements (95% CI =−20 to+22.8 b/min). According to the results, the Mod-D max using PSLS model and the Narita equation during the exhaustive treadmill exercise test is an accurate and reliable noninvasive alternative to the cumbersome, expensive, and time-consuming invasive methods. Therefore, the Mod-D max method can be used for the determination of AT in healthy young girls.

Características fisiológicas de corredores meio-fundistas de diferentes níveis competitivos

The aims of this study were: to compare indexes of the power and aerobic capacity, kinetics of O2 uptake and muscle power in two groups of middle-distance runners; to verify if the predicting performance is dependent of training level. Twenty-one male runners, nine classified as trained (group 1 – G1) and twelve moderately trained (group 2 - G2) performed the following tests: 1) time trial run in 1500-m; 2) maximal incremental test for determination of maximal oxygen uptake (VO2max), anaerobic threshold and running velocity at VO2max (vVO2max); 3) all-out exercise bout performed at vVO2max to determine time of support (Tlim) and the time to achieve VO2max (TAVO2max); 4) vertical jump. The main results showed that the power and aerobic capacity indexes were higher in G1, being able to differentiate the competitive level of the runners. The vVO2max explained the performance in 1500, regardless the training level.

Validation of Various Anaerobic Threshold Determination Methods Relating to Maximal Lactate Steady State in Rowing

Validation of Various Anaerobic Threshold Determination Methods Relating to Maximal Lactate Steady State in Rowing