Anaerobic threshold

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Anaerobic threshold in different categories of soccer players

Anaerobic threshold in different categories of soccer players

Abstract – Different variables can be used for the identification and monitoring of aerobic capacity in collective sports, with the anaerobic threshold (AT) being commonly used in long-duration team sports such as soccer, basketball, and handball. The aim of this study was to determine AT intensity in different categories of soccer players by evaluating running speed, heart rate (HR) and percent maximum HR (%HRmax), and to compare these intensities between three soccer categories. Nineteen U-17, 12 U-20 and 14 professional players volunteered for this study. The AT was defined as the exercise intensity at which blood lactate reaches a concentration of 4 mM (OBLA). AT was determined in a field test consisting of two to five 1000-m runs at constant speed. HR and blood lactate concentration recorded during the test were analyzed by linear interpolation. The running speed, HR and %HRmax at OBLA were determined. HRmax was higher in U-17 players (202 ± 7 bpm) than in professional players (193 ± 10 bpm) (p<0.05). AT expressed as %HRmax was lower in the U-17 (87.0 ± 1.1) and U-20 (86.3 ± 0.8) categories when compared to the professional category (91.2 ± 1.1) (p<0.05). Mean AT was 87% HRmax. No differences between categories were observed when AT was expressed as absolute HR values (bpm) or running speed. The intensity of AT is considered to be high in this group, with professional players presenting a higher AT than U-17 and U-20 players.
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Level of performance and stability of cardiopulmonary variables in the intensity of the ventilatory anaerobic threshold

Level of performance and stability of cardiopulmonary variables in the intensity of the ventilatory anaerobic threshold

Aerobic exercise through the continuous method is the most common running training prescription. The high-performance athletes train in a polarized way with ~75% of the training be- ing performed below or at the Ventilatory Anaerobic Threshold (VAT)¹. When performing exercise close to the VAT, we can observe a physiological steady state, a phenomenon character- ized by intrinsic adjustments of the organism to maintain the balance of energy substrates via aerobic metabolism 2,3 .

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Comparison of anaerobic threshold determined by visual and mathematical methods in healthy women

Comparison of anaerobic threshold determined by visual and mathematical methods in healthy women

8. Crescêncio JC, Martins LE, Murta LO Jr, Antloga CM, Kozuki RT, Santos MD, et al. Measurement of anaerobic threshold during dy- namic exercise in healthy subjects: Comparison among visual anal- ysis and mathematical models. Comput Cardiol 2003; 30: 801-804. 9. Soler AM, Folledo M, Martins LE, Lima-Filho EC, Gallo JL. Anaero- bic threshold estimation by statistical modelling. Braz J Med Biol Res 1989; 22: 795-797.

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Effect of the aerobic capacity on the validity of the anaerobic threshold for determination of the maximal lactate steady state in cycling

Effect of the aerobic capacity on the validity of the anaerobic threshold for determination of the maximal lactate steady state in cycling

ration of exercise performed at anaerobic threshold intensity (4 mM) during cycling. However, we believe that these data do not demonstrate that the validity of anaerobic threshold to estimate MLSS intensity is com- promised in endurance athletes. In fact, the concepts and mechanisms that can influence the MLSS and maximum exercise duration at a given exercise intensity (e.g., at MLSS intensity) may be different, and have not yet been completely established. Thus, our data do not support previously published specu- lations that higher aerobic capacity reduces the BLC at anaerobic threshold (11,12,14).
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Determination of anaerobic threshold through heart rate and near infrared spectroscopy in elderly healthy men

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

ABSTRACT | Background: Aging leads to low functional capacity and this can be reversed by safe and adequate exercise prescription. Objective: 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 (O 2 Hb) and deoxyhemoglobin (HHb) curves and compare indings with the heteroscedastic (HS) method applied to carbon dioxide production ( V  CO 2 ), 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. Method: 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. Results: We observed temporal equivalence and similar values of power (W), absolute oxygen consumption ( V  O 2 - mL/min), relative V  O 2 (mL.Kg –1 .min –1 ), and HR at AT by the detection methods performed. In addition, by the Bland-Altman plot, HR
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Effects of caffeine on time to exhaustion in exercise performed below and above the anaerobic threshold

Effects of caffeine on time to exhaustion in exercise performed below and above the anaerobic threshold

Anaerobic threshold was defined as the intensity (watts; W) corresponding to a lac- tate concentration of 4 mM and was deter- mined using a progressive test conducted on an electromagnetically braked cycle ergom- eter. The initial workload was 25 W and the intensity was increased by 25 W every 5 min until exhaustion. At the end of each stage, 25 µl of blood was collected from the ear lobe, into microcentrifuge tubes containing 50 µl NaF (1%). The intensity at 4 mM lactate concentration was calculated by linear inter- polation (8).

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Exercise may cause myocardial ischemia at the anaerobic threshold in cardiac rehabilitation programs

Exercise may cause myocardial ischemia at the anaerobic threshold in cardiac rehabilitation programs

Clinical implications: our results suggest that, in super- vised exercise training programs, exercise prescription based on the anaerobic threshold is still recommended for coronary artery disease with stress-induced myocardial ischemia. Nevertheless, because myocardial ischemia may be present, the presence of ST-segment depression and angina pectoris should determine a reduction in exercise intensity. These recommendations are valid, even after publication of the study by Noel et al. (27), which did not find significant changes in the course of only 11 patients in the presence of ST-segment depression of 1 mm. In pa- tients with diffuse and severe coronary artery disease, myocardial perfusion SPECT may be a useful adjunct for a more appropriate and accurate detection of ischemia, since it enables exercise to be prescribed more safely below the ischemic zone, regardless of the anaerobic threshold.
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Exercise at anaerobic threshold intensity and insulin secretion by isolated pancreatic islets of rats

Exercise at anaerobic threshold intensity and insulin secretion by isolated pancreatic islets of rats

To evaluate the efect of acute exercise and exercise training at the anaerobic threshold (AT) intensity on aerobic conditioning and insulin secretion by pancreatic islets, adult male Wistar rats were submitted to the lactate minimum test (LMT) for AT determination. half of the animals were submitted to swimming exercise training (trained), 1 h/day, 5 days/week during 8 weeks, with an overload equivalent to the AT. The other half was kept sedentary. At the end of the experimental period, the rats were submitted to an oral glucose tolerance test and to another LMT. Then, the animals were sacriiced at rest or immediately after 20 minutes of swimming exercise at the AT intensity for pancreatic islets isolation. At the end of the experiment mean workload (% bw) at AT was higher and blood lactate concentration (mmol/L) was lower in the trained than in the control group. Rats trained at the AT intensity showed no alteration in the areas under blood glucose and insulin during OGTT test. Islet insulin content of trained rats was higher than in the sedentary rats while islet glucose uptake did not difer among the groups. The static insulin secretion in response to the high glucose concentration (16.7 mM) of the sedentary group at rest was lower than the sedentary group submitted to the acute exercise and the inverse was observed in relation to the trained groups. physical training at the AT intensity improved the aerobic condition and altered insulin secretory pattern by pancreatic islets.
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Acute exercise performed close to the anaerobic threshold improves cognitive performance in elderly females

Acute exercise performed close to the anaerobic threshold improves cognitive performance in elderly females

The objective of the present study was to compare the effect of acute exercise performed at different intensities in relation to the anaerobic threshold (AT) on abilities requiring control of executive functions or alertness in physically active elderly females. Forty-eight physically active elderly females (63.8 ± 4.6 years old) were assigned to one of four groups by drawing lots: control group without exercise or trial groups with exercise performed at 60, 90, or 110% of AT (watts) and submitted to 5 cognitive tests before and after exercise. Following cognitive pretesting, an incremental cycle ergometer test was conducted to determine AT using a fixed blood lactate concentration of 3.5 mmol/L as cutoff. Acute exercise executed at 90% of AT resulted in significant (P < 0.05, ANOVA) improvement in the performance of executive functions when compared to control in 3 of 5 tests (verbal fluency, Tower of Hanoi test (number of movements), and Trail Making test B). Exercising at 60% of AT did not improve results of any tests for executive functions, whereas exercise executed at 110% of AT only improved the performance in one of these tests (verbal fluency) compared to control. Women from all trial groups exhibited a remarkable reduction in the Simple Response Time (alertness) test (P = 0.001). Thus, physical exercise performed close to AT is more effective to improve cognitive processing of older women even if conducted acutely, and using a customized exercise prescription based on the anaerobic threshold should optimize the beneficial effects.
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Evaluation of anaerobic threshold in non-pregnant and pregnant rats

Evaluation of anaerobic threshold in non-pregnant and pregnant rats

Several studies present different methodologies and results about intensity exercise, and many of them are performed in male rats. However, the impact of different type, intensity, frequency and duration of exercise on female rats needs more investigation. From the analysis of blood lactate concentration during lactate minimum test (LacMin) in the swimming exercise, the anaerobic threshold (AT) was identified, which parameter is defined as the transition point between aerobic and anaerobic metabolism. LacMin test is considered a good indicator of aerobic conditioning and has been used in prescription of training in different exercise modalities. However, there is no evidence of LacMin test in female rats. The objective was to determine AT in non-pregnant and pregnant Wistar rats. The LacMin test was performed and AT defined for mild exercise intensity was from a load equivalent to 1% of body weight (bw), moderate exercise as carrying 4% bw and severe intensity as carrying 7% bw. In pregnant rats, the AT was reached at a lower loading from 5.0% to 5.5% bw, while in non-pregnant the load was from 5.5% to 6.0% bw. Thus, this study was effective to identify exercise intensities in pregnant and non-pregnant rats using anaerobic threshold by LacMin test.
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Comparison of maximal lactate steady state with V2, V4, individual anaerobic threshold and lactate minimum speed in horses

Comparison of maximal lactate steady state with V2, V4, individual anaerobic threshold and lactate minimum speed in horses

authors as the anaerobic threshold (Bas et al., 2000), are often utilized due to their practicality and objectivity. Other methods for assessing the AT through lactacidemia, such as individual anaerobic threshold (IAT) and lactate minimum speed (LMS), were proposed for humans and there are few reports on LMS in horses (Gondim et al., 2007), and none or almost none regarding IAT. In humans, many studies were conducted to test the capacity of different methods predicting exercise intensity at threshold, which approximate those predicted by MLSS, and despite this, there is much controversy on the subject (Faude et al., 2009). The aim of this study was to compare the methods of assessing the anaerobic threshold based on lactacidemia, V 2 , V 4 , IAT and LMS with the MLSS method,
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Anaerobic Threshold Biophysical Characterisation of the Four Swimming Techniques

Anaerobic Threshold Biophysical Characterisation of the Four Swimming Techniques

through a biophysical approach for all four conventional swimming techniques. Despite a variety of different AnT testing procedures  in swimming, the majority are not regularly used, since: (i) the non- invasive 30 min and 2 000 m tests [7, 25] are monotonous and not motivational, possibly leading to an underestimation of the final  result; (ii) the maximal lactate steady state test [10, 26], although still considered the gold standard for assessing aerobic capacity re- quires, at least, 3 consecutive days of testing; (iii) the critical veloc- ity test, composed by, at least, two maximal intensity bouts, can lead to an overestimation of the final result if a distance of ~15 min  is not used [27]; (iv) the long duration tests probably are not per- formed at constant velocities, reflecting different intensities levels,  and are difficult to apply using simultaneous swimming techniques  ▶Fig. 2 Individual and mean ± standard deviation envelope blood lactate concentrations vs velocity curves for individual anaerobic threshold as- sessment in each conventional swimming technique.
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Determination of anaerobic threshold in rats using the lactate minimum test

Determination of anaerobic threshold in rats using the lactate minimum test

The break point of the curve of blood lactate vs exercise load has been called anaerobic threshold (AT) and is considered to be an important indicator of endurance exercise capacity in human subjects. There are few studies of AT determination in animals. We describe a protocol for AT determination by the “lactate minimum test” in rats during swimming exercise. The test is based on the premise that during an incremental exercise test, and after a bout of maximal exercise, blood lactate decreases to a minimum and then increases again. This mini- mum value indicates the intensity of the AT. Adult male (90 days) Wistar rats adapted to swimming for 2 weeks were used. The initial state of lactic acidosis was obtained by making the animals jump into the water and swim while carrying a load equivalent to 50% of body weight for 6 min (30-s exercise interrupted by a 30-s rest). After a 9- min rest, blood was collected and the incremental swimming test was started. The test consisted of swimming while supporting loads of 4.5, 5.0, 5.5, 6.0 and 7.0% of body weight. Each exercise load lasted 5 min and was followed by a 30-s rest during which blood samples were taken. The blood lactate minimum was determined from a zero- gradient tangent to a spline function fitting the blood lactate vs workload curve. AT was estimated to be 4.95 ± 0.10% of body weight while interpolated blood lactate was 7.17 ± 0.16 mmol/l. These results suggest the application of AT determination in animal studies con- cerning metabolism during exercise.
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Identification of anaerobic threshold using heart rate response during dynamic exercise

Identification of anaerobic threshold using heart rate response during dynamic exercise

The objective of the present study was to characterize the heart rate (HR) patterns of healthy males using the autoregressive inte- grated moving average (ARIMA) model over a power range as- sumed to correspond to the anaerobic threshold (AT) during dis- continuous dynamic exercise tests (DDET). Nine young (22.3 ± 1.57 years) and 9 middle-aged (MA) volunteers (43.2 ± 3.53 years) performed three DDET on a cycle ergometer. Protocol I: DDET in steps with progressive power increases of 10 W; protocol II: DDET using the same power values as protocol 1, but applied randomly; protocol III: continuous dynamic exercise protocol with ventila- tory and metabolic measurements (10 W/min ramp power), for the measurement of ventilatory AT. HR was recorded and stored beat- to-beat during DDET, and analyzed using the ARIMA (protocols I and II). The DDET experiments showed that the median physical exercise workloads at which AT occurred were similar for protocols I and II, i.e., AT occurred between 75 W (116 bpm) and 85 W (116 bpm) for the young group and between 60 W (96 bpm) and 75 W (107 bpm) for group MA in protocols I and II, respectively; in two MA volunteers the ventilatory AT occurred at 90 W (108 bpm) and 95 W (111 bpm). This corresponded to the same power values of the positive trend in HR responses. The change in HR response using ARIMA models at submaximal dynamic exercise powers proved to be a promising approach for detecting AT in normal volunteers. Correspondence
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Rev Bras Med Esporte  vol.19 número4

Rev Bras Med Esporte vol.19 número4

exercise stage (800 m). The exercise velocity control was perfor- med through sound signals at every 50 m in order to help the subject control and keep the pre-set intensity. A 60 s pause after each exercise stage was standardized for blood samples collec- tion. The blood samples were collected at minutes three, five and seven after the 300 m race, immediately after each exercise stage and after the five and seven minutes after the last exercise The anaerobic threshold velocity (vLAn) (estimated by the minimum lactate test) corresponded to the zero derivate of the polynomial adjustment of second degree between intensity and lactate.
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Rev Bras Med Esporte  vol.11 número4

Rev Bras Med Esporte vol.11 número4

In relation to the anaerobic threshold determination based on the lac and gluc responses, our results indicate that the IAT and IGT reflect the same parameter (table 2). A possible explanation for the increase on gluc after reaching the anaerobic threshold during incremental tests (figure 2) is that the adrenergic activity and the release of hormones associated to hyperglycemia – such as adren- aline, glucagon and cortisol – are increased at intensities above the anaerobic threshold (29) , resulting in increased gluc and enabling the

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Rev Bras Med Esporte  vol.12 número6 en a05v12n6

Rev Bras Med Esporte vol.12 número6 en a05v12n6

obic threshold (AT). The present study had as objective to compare oxygen consumption and anaerobic threshold in professional soc- cer and indoor soccer athletes in a progressive test. 31 male indi- viduals voluntarily participated in the test, being: 19 professional soccer athletes and 12 professional indoor soccer athletes. The athletes w ere submitted to a progressive cardiorespiratory evalua- tion protocol through the ergospirometric method, and the results w ere analyzed concerning their statistical difference through the t- Student test (p < 0,05). The average V O 2 peak indices betw een the tw o groups did not present statistically significant difference (p > 0,05); how ever, there w as statistically difference betw een the tw o groups concerning the anaerobic threshold (AT) (p < 0,05). Based on the results obtained in our study w e concluded that even prac- ticing sports w ith different characteristics, the athletes from both groups have similar indices of oxygen consumption. Nevertheless, the anaerobic threshold betw een the tw o groups did not present the same similarity, suggesting higher predominance of anaerobic metabolism during exercise in the indoor soccer athletes.
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Rev. bras. cineantropom. desempenho hum.  vol.14 número3

Rev. bras. cineantropom. desempenho hum. vol.14 número3

Abstract – he aim of this study was to compare anaerobic threshold (AT) as determined by four diferent methods with maximal lactate steady state (MLSS) in endurance run- ners. Nine moderately trained runners performed the following tests on diferent days: a maximal incremental exercise test to determine maximal oxygen uptake (VO 2 max), velocity at VO 2 max (vVO 2 max), and blood lactate response; and two to ive 30-min constant load tests to determine MLSS. Based on the incremental test, four methods of AT determination were used: AT1 – velocity at 3.5 mmol.L -1 blood lactate; AT2 – velocity
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Rev. bras. cineantropom. desempenho hum.  vol.19 número1

Rev. bras. cineantropom. desempenho hum. vol.19 número1

Abstract – Several studies showed that respiratory exchange ratio (RER) have been used as an alternative to evaluate the aerobic capacity in a single incremental test. However, few studies have investigated trained runners. he aim of this study was to verify if the respiratory exchange ratio (RER) could be used as an alternative criterion for estimating anaerobic threshold (AT) in long-distance runners. Nineteen male long-distance run- ners volunteered to participate in the study. An incremental treadmill test was performed with initial speed of 10 km·h -1 with increments of 1 km·h -1 every 1 min until voluntary
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Arq. Bras. Cardiol.  vol.73 número4

Arq. Bras. Cardiol. vol.73 número4

When the values of the maximum heart rate in the groups of patients in functional classes I, II, and III were compared, we observed significant differences. For the values of heart rate in the anaerobic threshold, an index con- sidered representative during the exercise in the transition of the aerobic to the compensated anaerobic metabolism, no significant differences between the groups were observed. On the other hand, in the respiratory compensation point, which is the exercise threshold which the buffer system and sodium bicarbonate do not manage to compensate for the lactate produced by the increase in the amount of exercise, we noted a significant difference in group III, which compri- sed the most critically ill patients. The differences in heart rate in the patients with heart failure according to the func- tional classes may be explained by muscle factors and by the chronotropic, flow and sympathetic stimulation dys- functions. The chronotropic dysfunction causes the heart to act as if it were denervated in the control of the heart rate in heart failure. One of the probable causes is the reduction in the number of receptors of cardiac norepinephrine and a total increase in serum norepinephrine, probably due to an increase in neural sympathetic activity; this is more accentuated according to the severity of the disease 20 . Ano-
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