This study examined whether the critical power (CP) and anaerobic work capacity (AWC) estimates from the CP 3-min all-out (CP3min) test were affected by the percentage of body weight used to set the resistance on a Monark cycle ergometer. Twenty-one subjects (11 women and 10 men) were placed into one of three groups (n=7) based on activity level; recreationally trained (REC), aerobic and anaerobic sport (SPORT), and endurance trained (END). The CP3min test was conducted at 4.5% of body weight (CP4.5%) and at a resistance setting based on group activity level (CPACT; REC = 3%, SPORT = 4%, and END = 5% of body weight). There were no differences between the CP4.5% or CPACT estimates in any of the three training groups. The AWC3% estimates were significantly lower than the AWC4.5% for the REC group, but there were no differences in the AWC4.5% and AWCACT for the SPORT or END groups.The principal finding of this study was that a resistance of 4.5% of body weight for CP3-min test may be used to estimate CP and AWC, without regard to the training status of the subjects.

The ability to exercise for more than a short period requires energy to be supplied by using oxygen (aerobic energy supply). How quickly we can supply energy depends on how much oxygen we can deliver to muscles. Similarly, delivery of oxygen (O2 del) to the brain is important as brief, transient disruptions can cause nausea or fainting. Therefore, regulation of O2 del so that the O2 supply matches the metabolic requirement (O2 del matching metabolic demand) is essential to exercise tolerance and brain function. O2 del to the brain is often researched in response to orthostatic stress, however little is known about vascular responses protecting O2 del. In muscle, use of a forearm exercise model is common as measuring O2 del is difficult in other exercise modalities. Unfortunately, it is also difficult to measure/test metabolism in the forearm. Hence, measuring O2 del response to exercise at a known metabolic intensity is difficult. Purpose: To investigate O2 del matching metabolic demand in the following manner: 1) develop a repeatable and reliable critical power (CP, highest sustainable rate of aerobic metabolism) test for the forearm exercise model 2) discover if individual differences in O2 del account for differences in forearm CP (fCP) 3) determine if fCP is sensitive to changes in O2 del 4) characterize cerebral vascular response to an orthostatic challenge Methods: Echo and Doppler ultrasound measured blood flow through the brachial artery. Venous blood samples were used to measure hemoglobin and O2 content for calculations of O2 del and consumption. Middle cerebral blood velocity measured via transcranial Doppler ultrasound. Blood pressure was measured using finger photoplethysmography. Results: 1) fCP can be accurately estimated from a maximal effort handgripping test 2) Inter-individual differences in O2 del account for most of the variance in fCP 3) fCP is sensitive to changes in O2 del 4) cerebral vascular responses blunt cerebral hypoperfusion in response to initial orthostatic hypotension. Conclusions: CP is an exercise characteristic of aerobic metabolism which is dependent on and sensitive to O2 del. Therefore, fCP can be used in the forearm exercise model to research O2 del-metabolism matching. / Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2013-01-04 15:04:44.391

The hyperbolic power-duration relationship for high-intensity exercise is defined by two parameters: an asymptote (critical power; CP) reflecting the highest sustainable rate of oxidative metabolism, and a curvature constant (W'), which indicates a fixed amount of work that can be completed above CP (W>CP). According to the CP model of bioenergetics, constant work rate exercise above CP depletes the capacity-limited W' with fatigue occurring when W' is completely expended. The complete depletion of W' has been reported to occur when VO2max is attained and a critical degree of muscle metabolic perturbation (decline of finite anaerobic substrates and accumulation of fatigue-related metabolites) is reached. However, while the CP model is effective at predicting metabolic perturbation and the tolerable duration of severe-intensity constant work rate (CWR) exercise, it is unclear if metabolic perturbation and exercise performance can be explained by the CP model when different methods of work rate imposition are applied. Therefore, the purpose of this thesis was to: 1) investigate the efficacy of the CP concept to predict performance in exercise tests using different work rate forcing functions; and 2) explore whether the physiological bases for W' are consistent across different methods of work rate imposition. In study 1, compared to severe-intensity CWR exercise, the tolerable duration of intermittent severe-intensity exercise with heavy- (S-H) moderate- (S-M) and light-intensity (S-L) ‘recovery’ intervals was increased by 47%, 100% and 219%, respectively. W>CP (W') was significantly greater by 46%, 98%, and 220% for S-H, S-M and S-L, respectively, when compared to S-CWR, and the slopes for the increases in VO2 and iEMG were progressively lowered as the recovery work rate was reduced. In study 2, both the VO2max and W>CP were similar across incremental cycling protocols that imposed a fixed ramp rate and cadence (4.33 ± 0.60 L•min-1; 14.8 ± 9.2 kJ), a fixed ramp rate with cadence self-selected by the subjects (4.31 ± 0.62 L•min-1; 15.0 ± 9.9 kJ) and a step incremental test where subjects were instructed to select power output according to prescribed increments in ratings of perceived exertion (4.36 ± 0.59 L•min-1; 13.0 ± 8.4 kJ). In study 3, the VO2max and W>CP were also not different across a 3 min all-out cycling test (4.10 ± 0.79 L•min-1; 16.5 ± 4.0 kJ), cycling at a constant work rate predicted to lead to exhaustion in 3 min until the limit of tolerance (4.20 ± 0.77 L•min-1; 16.6 ± 7.4 kJ) and a self-paced 3 min work-trial (4.14 ± 0.75 L•min-1; 15.3 ± 5.6 kJ). In study 4, after completing severe-intensity exercise (>CP) to exhaustion, muscle homeostasis ([PCr], pH, [ADP] and [Pi]) returned towards baseline and subjects were able to exercise for at least 10 min at a heavy-intensity work rate (<CP); however, when the work rate was lowered but remained in the severe-intensity domain (>CP), muscle metabolites ([PCr], pH, [ADP] and [Pi]) did not recover and exercise tolerance was severely limited (39 ± 31 s). Finally in study 5, during severe-intensity intermittent knee extension exercise, the tolerable duration of exercise was 304 ± 68 s when 18 s recovery was allowed and was increased by ~69% and ~179% when the intermittent recovery periods were extended to 30 s and 48 s, respectively. The increased exercise tolerance with longer recovery periods occurred in concert with increased W>CP (3.8 ± 1.0 kJ, 5.6 ± 1.8 kJ and 7.9 ± 3.1 kJ for the intermittent protocols with 18, 30 and 48 s of recovery, respectively) and a delayed attainment of critical intramuscular metabolite concentrations ([PCr], pH, [ADP] and [Pi]). Therefore, the results of this thesis demonstrate that fatigue during various high-intensity exercise protocols is influenced by the capacity to complete work above the CP (W') and that W' depletion is linked to the attainment of VO2max and the attainment of critical levels of intramuscular [PCr], pH, [ADP] and [Pi]. These findings suggest that the CP model can be adapted to predict the degree of metabolic perturbation and exercise performance across a range of exercise settings in humans.

The critical power (CP) model includes two constants: the CP and the W′ [P = W′ / t) + CP]. The W′ is the finite work capacity available above CP. Power output above CP results in depletion of the W′; complete depletion of the W′ results in exhaustion. It is possible to model the charge and discharge of the W′ during intermittent exercise using a novel integrating model (the W′BAL model), and to generate a function describing a curvilinear relationship between time constants of reconstitution of the W′ in terms of the difference between recovery power and CP (DCP) (r2 = 0.77). The depletion of the W′ as predicted by the W′BAL model during intermittent exercise is linearly related to the rise in V ̇O_2 above exercise baseline (r2 = 0.82 – 0.96). During intermittent exercise, the W′BAL model is generally robust with respect to the length of work and recovery interval, yielding a mean under-prediction of the W′BAL of only -1.6 ±1.1 kJ. The amount of W′ remaining after a period of intermittent exercise correlates with the difference between the subject’s V ̇O_2 at that time (V ̇O_2START) and V ̇O_2PEAK (DVO2) (r = 0.79, p < 0.01). Moreover, the W′BAL model also performs well in the field, permitting accurate estimation of the point at which an athlete becomes exhausted during hard training or competition (mean W′BAL at exhaustion = 0.5 ± 1.3 kJ (95% CI = 0 – 0.9 kJ). The W′BAL model meets the mathematical criteria of an excellent diagnostic test for exhaustion (area under ROC curve = 0.91). 31P magnetic resonance spectroscopy during single leg extensor exercise revealed a correlation between the recovery of the W′BAL model and recovery of creatine phosphate ([PCr]) after a bout of exhaustive single leg extensor exercise (r = 0.99, p < 0.01). The W′BAL model also accurately predicted recovery of the W′ in this setting (r = 0.97, p < 0.05). However, a complete understanding of the relationship between the depletion and recovery of [PCr] and the depletion and recovery of the W′ remains elusive. Muscle carnosine content is curvilinearly related to the rate of W′BAL recovery, with higher muscle carnosine associated with faster recovery, with implications for muscle buffering capacity and calcium handling. The W′BAL model may be recast in the form of a differential equation, permitting definition of the time constant of recovery of the W′BAL in terms of the subject’s known W′ and the DCP. This permits the scaling of the model to different muscle groups or exercise modalities. Moreover, modifications to this mathematical form may help explain some of the variability noted in the model in earlier studies, suggesting novel avenues of research. However, the present formulation of the W′BAL model is mathematically robust and represents an important addition to the scientific armamentarium, which may aid the understanding the physiology of human performance.

Doctor of Philosophy / Department of Anatomy and Physiology / Thomas J. Barstow / The physiological mechanisms determining the tolerable duration of exercise dictate human physical accomplishments across all spectrums of life. Despite extensive study, these specific mechanisms, and their dependence on oxygen delivery and oxygen utilization, remain, a certain extent, undefined. The purpose of this dissertation was to test the overarching hypothesis that muscle contraction characteristics (i.e., intensity of contraction, muscle contraction-relaxation duty cycle, etc.) alter oxygen delivery and oxygen utilization, which directly influence the power-duration relationship and fatigue development, and therefore, exercise tolerance. To accomplish this, specific interventions of altered muscle contraction-relaxation duty cycle and blood flow occlusion were utilized. In the first investigation (Chapter 2), we utilized low and high muscle contraction-relaxation duty cycles to alter blood flow to the active skeletal muscle, demonstrating that critical power (CP) was reduced with the high muscle contraction-relaxation duty cycle due to a reduction in blood flow, while the curvature constant (W’) was not altered. The second investigation (Chapter 3) utilized blood flow occlusion to show that CP was reduced and W’ increased for blood flow occlusion exercise conditions compared to control blood flow exercise conditions. The final investigation (Chapter 4) utilized periods of blood flow occlusion during and post-exercise to reveal greater magnitudes of peripheral and central fatigue development during blood flow occlusion exercise compared to control blood flow exercise. Moreover, this investigation demonstrated that W’ was significantly related to the magnitude of fatigue development. Collectively, alterations in oxygen delivery and oxygen utilization via muscle contraction characteristics and blood flow occlusion directly influence CP and the magnitude of fatigue development. However, W’ does not appear to be influenced by manipulations in oxygen delivery and oxygen utilization, per se. Rather, W’ may be determined by the magnitude of fatigue accrued during exercise, which is dependent upon oxygen delivery and oxygen utilization. The novel findings of the investigations presented in this dissertation highlight important physiological mechanisms that determine exercise tolerance and demonstrate the need for interventions that improve oxygen delivery and oxygen utilization in specific populations, such as those with chronic heart failure or chronic obstructive pulmonary disease, to improve exercise tolerance.

Master of Science / Department of Kinesiology / Thomas J. Barstow / The accumulation of reactive oxygen species (ROS) has been linked to the development of muscular fatigue. Antioxidant administration has the potential to counteract the increased levels of ROS, leading to improvements in performance. N-acetylcysteine (NAC), a nonspecific antioxidant, is especially promising due to its ability to support the biosynthesis of glutathione, one of the primary endogenous antioxidants. Despite this, the effects of NAC on time to fatigue appear to be dependent upon the exercise intensity, with the more pronounced effects evident at submaximal exercise intensities. The purpose of this study was to determine the effects of an acute dose of NAC on whole body fatigue, critical power (CP) and W’ during high-intensity exercise. It was hypothesized that pretreatment with NAC would result in (1) an increase in time to fatigue (TTF), CP and W’, (2) NAC administration would attenuate changes in the EMG responses indicative of fatigue, and (3) speeding of the kinetics of the primary phase of VO2 and a reduction in the slow component. Seven healthy, active males (age: 21.4 ± 1.6 years, weight: 89.1 ± 11.0 kg, height: 183 ± 5 cm) completed an incremental ramp test until exhaustion for the determination of peak VO2 and power. Four tests were subsequently performed at power outputs corresponding to 80, 90, 100, and 110% Pmax under NAC and placebo (PLA) conditions. NAC resulted in a significant increase in [tGSH] in red blood cells compared to baseline and PLA condition. TTF was significantly increased only in the 80% Pmax trial (p = 0.033). CP was also significantly higher with NAC (NAC: 232 ± 28 W vs PLA: 226 ± 31 W; p = 0.032), but W’ showed a tendency to decrease (NAC: 15.5 ± 3.8 kJ vs W’: 16.4 ± 4.5 kJ). The change in W’ was negatively related to CP (r = -0.96), indicating that the increase in CP was associated with a decrease in W’. EMG analysis revealed a tendency for MdPF and RMS to demonstrate less of a change with NAC. There were no significant differences in VO2 kinetics, but an inverse relationship was observed between the change in τp and the magnitude of the slow component expressed both in absolute terms (r = -0.632, p = 0.007) and as a gain (r = -0.751, p = 0.0005). We conclude that NAC was effective in delaying fatigue and improving exercise performance at 80% peak power, although the exact mechanisms are still unclear.

The hyperbolic relationship between power output and endurance time can be measured using all-out exercise. The aims of this thesis were to (i) assess whether the all-out test could be used under novel testing protocols to provide valid power-duration (P-D) parameter estimates; and (ii) attempt to elucidate the likely physiological composition of the P-D curvature constant. All-out tests were initiated from moderate-(M), heavy-(H) and severe-(S2 & S4) intensity ‘baselines’ (chapter 4). The work performed above end power (WEP) was not different to control under M or H conditions but was significantly, predictably reduced under the S2 & S4 conditions (control: 16.3 ± 2.2; M: 17.2 ± 2.4; H: 15.6 ± 2.3 kJ, P > 0.05; S2: 11.5 ± 2.5; S4: 8.9 ± 2.2 kJ, P < 0.05). The 3-min all-out test end power (EP) parameter was unaffected. Muscle glycogen may form part of the WEP. Type I (T1) and type II (T2) muscle fibres were depleted of their glycogen content prior to the all-out test (chapter 5). EP and WEP were unaffected by either T1 or T2 glycogen depletion. The all-out tests was conducted under hypoxic conditions alongside the criterion assessment of the P-D relationship (chapter 6). Normobaric moderate hypoxia caused a reduction in CP (control: 175 ± 25; hypoxia: 132 ± 17 W, P < 0.001) without affecting W′ (control: 13.2 ± 2.2; hypoxia: 12.3 ± 2.7 kJ, P > 0.05). The 3-min all-out test provided EP and WEP estimates, which did not differ to CP and W′ (control: EP 172 ± 30 W, WEP 12.0 ± 2.6 kJ; hypoxia EP 134 ± 23 W, WEP 12.5 ± 1.4 kJ, P > 0.05) providing the ergometer resistance was adjusted for the hypoxic conditions. Furthermore, a significant negative relationship was observed between %∆ ( O2peak – CP) and %∆W′ (r = -0.83, P < 0.001); thus, W′ may represent the relative ‘size’ of the severe-intensity domain. The all-out test was used to track training-induced changes in P-D parameters in response to 6-weeks of sprint or endurance training (chapter 7). EP & WEP were differently altered compared to CP and W′ following sprint training (CP 12 ± 9; EP -0 ± 9 % change; W′ -5 ± 25; WEP 11 ± 15 % change). The all-out test reliably tracked changes in CP and W′ following endurance training. In conclusion, the all-out test provides reliable EP and WEP values. Its validity is acceptable, but is perhaps affected by exercise training that is specific to the execution of the test. The W′ appears to be determined, to a large extent, by the relative size of the severe-intensity domain.

Tittle: Curve- fitting of the critical power in swimming for triathletes Objectives: Comparison of curve-fitting of the critical power at swimmers and triathletes in different performance categories. Methods: This thesis is based on a research. The research took place in laboratories FTVS UK and there was used the swimming simulator called Biokinetic for test measurements. Elite swimmers, triathletes and hobby triathletes participated in the tests. Sportsmen took part in 4 tests. The first test - 10 crawl strokes, the second test - 20 crawl strokes, the third test - 50 crawl strokes and the fourth test - 200 crawl strokes. The obtained data were worked out by using T-test and they were written into tables and charts in programs Excel and Word. There was used program PASW Statistics 18 for statistical processing. Results: It was discovered, that there were no differences in performances in tests by using Biokinetic between swimmers and triathletes. Hobby triathletes made the same performances as elite triathletes. The biggest difference in performances was at female hobby triathletes, who were worse than female elite triathletes and female swimmers. Keywords: Critical power, swimming, triathlon, Biokinetic, testing

Submitted by leonardo Perinotto abdalla (leoabdalla@live.com) on 2018-03-16T15:22:43Z No. of bitstreams: 1 Dissertação .pdf: 4793508 bytes, checksum: 9e8ed8362972b0fe05f4c6d100e03979 (MD5) / Approved for entry into archive by Ana Paula Santulo Custódio de Medeiros null (asantulo@rc.unesp.br) on 2018-03-16T16:39:16Z (GMT) No. of bitstreams: 1 abdalla_lhp_me_rcla.pdf: 4789566 bytes, checksum: 85a14005b703aa3dd03acc7d79a891de (MD5) / Made available in DSpace on 2018-03-16T16:39:16Z (GMT). No. of bitstreams: 1 abdalla_lhp_me_rcla.pdf: 4789566 bytes, checksum: 85a14005b703aa3dd03acc7d79a891de (MD5) Previous issue date: 2018-02-28 / O objetivo deste estudo foi testar as hipóteses de que o torque critico (TC) (expresso como % de uma contração voluntária máxima, CVM) é maior para os flexores plantares (FP) com relação aos músculos extensores do joelho (EJ), enquanto o impulso acima do TC (W’) é maior para EJ do que FP. Assim, esperamos que a tolerância ao exercício seja maior para EJ do que FP somente durante o exercício realizado acima de TC. Após a determinação da CVM, 11 homens realizaram dois testes All-Out de 5 min para determinar TC e W’. Os onze sujeitos realizaram mais 5 testes isométricos intermitentes até a falha da tarefa, durante 5 visitas, + 5% TC e - 5% TC para ambos os músculos, e 1 teste para EJ na mesma intensidade de exercício em (% CVM) correspondente a + 5% TC do FP. Os onze participantes realizaram mais 4 testes isométricos intermitentes, até a exaustão, + 5% e - 5% do TC e 1 teste para EJ na intensidade do exercício (% CVM) correspondente a + 5% do TC do FP, para o EJ. O W '(7243,2 ± 1942,9 vs. 3357,4 ± 1132,3 N · m · s) e CT (84,4 ± 24,8 vs. 73,9 ± 19,5 N · m) foram significativamente menores para FP em comparação com EJ. A tolerância ao exercício foi significativamente mais longa para FP (300,7 ± 156,7 s) do que EJ (156,7 ± 104,3 s) em CVM semelhante (~60%) e significativamente menor para FP (300,7 ± 156,7 s) do que EJ (697,0 ± 243,7 s) na condição de + 5% do TC. No entanto, nenhuma diferença significativa foi observada para condição de - 5% do TC (EJ = 1030,2 ± 495,4 s vs. FP = 1028,3 ± 514,4 s). Assim, o limite de tolerância durante as contrações isométricas submáximas é influenciado pela CVM absoluta apenas durante o exercício realizado em intensidade acima do TC, o que parece ser explicado por diferenças nos valores de TC (expressos em % CVM) e o W’. / The objective of this study was to test the hypotheses that critical torque (CT) (expressed as % maximal voluntary contraction; MVC) is higher for plantar flexors (PF) than knee extensors (KE) muscles, whereas impulse above ET (W’) is higher for KE than PF. Thus, we expected that exercise tolerance would be longer for KE than PF only during the exercise performed above ET. After the determination of MVC, 11 men performed two 5-min all-out tests to determine ET and IET. Eleven participants performed a further 4 intermittent isometric tests, to exhaustion, at ET + 5% and ET – 5%, and 1 test for KE at the exercise intensity (%MVC) corresponding to ET + 5% of PF. The W’ (7243.2 ± 1942.9 vs. 3357.4 ± 1132.3 N·m·s) and CT (84.4 ± 24.8 vs. 73.9 ± 19.5 N·m) were significantly lower in PF compared with KE. The exercise tolerance was significantly longer for PF (300.7 ± 156.7 s) than KE (156.7 ± 104.3 s) at similar %MVC (�����60%), and significantly shorter for PF (300.7 ± 156.7 s) than KE (697.0 ± 243.7 s) at ET + 5% condition. However, no significant difference was observed for ET – 5% condition (KE = 1030.2 ± 495.4 s vs. PF = 1028.3 ± 514.4 s). Thus, the limit of tolerance during submaximal isometric contractions is influenced by absolute MVC only during exercise performed above ET, which seems to be explained by differences on both CT (expressed as %MVC) and W’ values.

Orientador: Fúlvia de Barros Manchado Gobatto / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação Física / Made available in DSpace on 2018-08-26T17:41:20Z (GMT). No. of bitstreams: 1 Ferrari_HomeroGustavo_D.pdf: 2945380 bytes, checksum: 47a86cf6a1fd0c4927ac8ae901bbebf3 (MD5) Previous issue date: 2014 / Resumo: Introdução: a canoagem slalom é um esporte olímpico desde de 1992 e que cresce a cada ano no mundo todo. No entanto, poucas informações científicas têm sido encontradas na literatura, sobretudo, em relação a avaliação fisiológica e treinamento. Objetivo: padronizar testes específicos em remada atada e livre para avaliação da aptidão aeróbia de canoístas slalom de elite e verificar a correlação dos índices de aptidão aeróbia fornecidos pelos testes com o desempenho em prova simulada. Métodos: a amostra foi composta por 12 atletas pertencentes a Seleção Brasileira Permanente de Canoagem Slalom com idade média 18 ± 2 anos. Os testes de canoagem atada foram realizados com o auxílio de um aparato denominado Sistema de Medição de Força Atado (SIMFA), composto por célula de carga e módulo amplificador de sinais. Todas as avaliações foram realizadas em piscina de 25m e sob caiaque modelo K1. A máxima fase estável de lactato (MFEL) atada foi determinada a partir de três intensidades que variaram de 35,5N à 70,3N. Para a obtenção da força crítica (FC) foram utilizadas quatro cargas preditivas e ajustes matemáticos hiperbólico (FChiper) e linear (FClin). As avaliações em remada livre (velocidade crítica (VC) e MFEL) foram realizadas em lagoa. A VC foi obtida pelo modelo "distância vc. tempo" utilizando desempenhos máximos nas distâncias de 300, 450 e 600 metros. Para determinar a iMFEL os atletas foram submetidos a três testes contínuos com duração de 30 min, separados por intervalo de 24 horas entre eles, realizados em sistema de vai e vem na distância de 50 metros. Como indicador de desempenho adotou-se o tempo em prova simulada de canoagem slalom (TP), executada em canal artificial. Em adição o lactato sanguíneo (LACsang) pós prova foi mensurado. Resultados: os principais resultados das avaliações atadas, indicam não haver diferença entre a iMFEL e FChiper e entre FChiper e FClin, no entanto, a FClin foi significantemente maior que iMFEL. A FChiper foi altamente correlacionada com iMFEL (r= 0,78, p=0,002), bem como iMFEL foi correlacionada com desempenho (r = -0,67, p=0,016). Em relação as avaliações livres os resultados revelaram não haver diferença significativa entre a intensidade de VC (7,77 ± 0,28 Km/h) e iMFEL (7,50 ± 0,32), além disso, correlação significativa foi encontrada entre a intensidade de VC e desempenho em prova simulada (r= 0,84, p=0,03). Conclusões: em relação as avaliações atadas, foi possível padronizar testes atados para avaliação aeróbia de canoístas slalom, utilizando as metodologias de MFEL e FC, e também a possibilidade de utilizar o parâmetro aeróbio obtido pelo modelo de FC como uma avaliação não invasiva para estimar a MFEL. Já em relação as avaliações livres a VC obtida pelo modelo distância-tempo é válida para estimar a iMFEL em canoístas slalom de elite, além de se correlaciona com o desempenho em prova simulada. / Abstract: Introduction: canoe slalom is an Olympic sport since 1992 and that grows every year worldwide. However, limited scientific information has been found in the literature, especially in relation to training and evaluation physiological. Purpose: Standardize tethered specific tests and free tests for assessment of aerobic fitness elite slalom kayakers and additionally verify the correlation between indexex of aerobic fitness provided by tests with performance in simulated slalom race. Methods: the sample was composed of 12 athletes from the Canoe Slalom Brazilian Team with a mean age 18 ± 2 years. The tethered specific testst was performed using a denominated Tethered Canoe System (TCS) constructed specifically for this purpose composed of a load cell and signal amplifier module. All assessments were conducted in a 25-meter outdoor swimming pool using K1 kayak model. The tethered maximal lactate steady state (MLSS) was determined from three intensities ranging from 35,5N the 70,3N. Four predictive loads were used to obtain the critical force (CF) using two mathematical adjustments, hyperbolic (CFhiper) and linear (CFlin). Free specific tests assessments (critical velocity (CV) and MLSS) were performed in lake. The CV has been obtained by "distance-time" model using maximum performance at distances of 300, 450 and 600 meters. To determine the iMLSS athletes underwent three continuous lasting 30 min, separated by 24-hour interval between them, performed using a kayak "shuttle" exercise, with a 50-m course. The simulated race was conducted on a white water course and as performance indicator the total race time (Trace) was adopted. In addition, the blood lactate (LACsang) post race was measured. Results: the main results of tethered evaluation, indicate that the CFlin and CFhiper intensities did not differ, as well as CFhiper and iMLSS. However, CFlin was significantly higher than iMLSS. The iMLSS and CFhiper intensities were significantly correlated (r= 0.82, p=0.002) well as iMFEL was correlated with performance (r = -0.67, p = 0.016). Regarding the free evaluations, the results showed no significant difference between the intensity of CV (7.77 ± 0.28 Km / h) and iMLSS (7.50 ± 0.32) Moreover, a significant correlation was found between intensity CV and simulated race performance (r = 0.84, p = 0.03). Conclusions: regarding the tethered specific tests , was possible to standardize tests for aerobic evaluation in slalom kayakers, using the MLSS and CF methodologies and also the possibility to use the aerobic parameter obtained by the FC model as a noninvasive evaluation to estimate MLSS. In relation the free specific tests, the CV obtained by the distance-time model is valid for estimating the iMLSS in elite slalom kayakers and is correlated with performance in simulated race / Doutorado / Biodinamica do Movimento e Esporte / Doutor em Educação Física