Comparison of different test protocols to determine maximal lactate steady state intensity in swimming.

OBJECTIVES: This study compared step test, lactate minimum (LM) test and reverse lactate threshold (RLT) test protocols with maximal lactate steady state (MLSS) in free-swimming. All test protocols used fixed duration increments and high work-rate resolution (≤ 0.03 m·s-1) to ensure high sensitivity. DESIGN: Validation study. METHODS: 23 swimmers or triathletes (12 male and 11 female) of different ages (19.0 ±â€¯5.9 yrs) and performance levels (400 m personal best 1.38 ±â€¯0.13 m·s-1, FINA points 490 ±â€¯118) completed an incremental step test (+0.03 m·s-1 every 3 min) to determine speed at 4 mmol·L-1 and at modified maximal distance method, a LM test, a RLT test and two to five 30 min tests (±0.015 m·s-1) to determine MLSS. Following a 200 m all-out and a 5 min rest, LM was determined during an incremental segment (+0.03 m·s-1 every 2 min) as the nadir of the speed-lactate curve. After a priming segment with four increments (+0.06 m·s-1), RLT was determined as the lactate apex during a reverse segment (-0.03 m·s-1) every 3 min. RESULTS: The mean differences (± limits of agreement) to speed at MLSS were +1.0 ±â€¯4.1% (speed at 4 mmol·L-1), +1.5 ±â€¯3.5% (modified maximum distance method), -0.2 ±â€¯4.7% (LM) and 2.0 ±â€¯3.1% (RLT). All threshold concepts showed good agreement with MLSS pace (intraclass correlation coefficient ≥ 0.886). CONCLUSIONS: Test protocols with a fixed step duration and fine increments allowed high accuracy in estimating MLSS pace. With similar criterion agreement to the LM and RLT tests, incremental step tests appear more practicable due to less prior knowledge required and derivation of individual training zones.

Differences in iron intake during pregnancy influence in trainability response of male rat offspring / Diferenças na ingestão de ferro durante a gravidez influenciam na resposta à treinabilidade da prole de ratos machos

ABSTRACT Objective: To evaluate if different concentrations of iron in diets during pregnancy would interfere in the aerobic and anaerobic performance of the offspring, observed during 8-week swimming training and measured by lactate minimum test. Methods: Pregnant rats were divided into four groups with different dietary iron concentrations: standard (40mg/kg), supplementation (100mg/kg), restriction since weaning, and restriction only during pregnancy (4mg/kg). After birth, the offspring were assigned to their respective groups (Standard Offspring, Supplementation Offspring, Restriction Offspring or Restriction Offspring 2). The lactate minimum test was performed at three time points: before starting exercise training, after 4 weeks and after 8 weeks of exercise training. Results: The Restriction Offspring Group had a significant reduction in the concentration of lactate minimum and in swimming time to exhaustion, after 4 and 8 weeks of training as compared to before training. Therefore, the results showed the Restriction Offspring Group was not able to maintain regularity during training in lactate minimum tests. Conclusion: Our results suggested the Restriction Offspring Group showed a marked decrease in its performance parameters, which may have occurred due to iron restriction.

RESUMO Objetivo: Avaliar parâmetros aeróbios e anaeróbios da prole de ratas alimentadas com diferentes dietas de ferro durante a prenhez, por meio do teste de lactato mínimo. Métodos: As ratas prenhes foram divididas em quatro grupos com diferentes concentrações de ferro na dieta: padrão (40mg/kg), suplementação (100mg/kg), restrição desde o desmame e restrição apenas durante a gravidez (4mg/kg). Após o nascimento, os filhotes foram designados para seus respectivos grupos (Prole Padrão, Prole Suplementação, Prole Restrição ou Prole Restrição 2). O teste de lactato mínimo foi realizado em três momentos: antes de iniciar o treinamento físico, após 4 semanas e após 8 semanas de treinamento físico. Resultados: O Grupo Prole Restrição apresentou redução significativa na concentração do lactato mínimo e no tempo de natação até a exaustão, após 4 e 8 semanas de treinamento em relação ao período antes do início do treinamento. Assim, o Grupo Prole Restrição não foi capaz de manter regularidade durante o treinamento nos testes de lactato mínimo. Conclusão: Os resultados sugerem que o Grupo Prole Restrição apresentou diminuição acentuada nos parâmetros de desempenho, o que pode ter ocorrido devido à restrição de ferro.

Comparison of Different Blood Lactate Threshold Concepts for Constant Load Performance Prediction in Spinal Cord Injured Handcyclists.

BACKGROUND: Endurance capacity is one of the main performance determinants in handcycling. There are two exercise test procedures primarily applied to determine endurance capacity, to verify training adaptations and predict race performance. This study aims to evaluate the agreement of these applied concepts in handcycling. METHODS: In a repeated measures cross-over design, 11 highly trained male spinal cord injured (Th12 to L1) handcyclists (age: 40 ± 9 years, height: 183 ± 8 cm, body mass: 73.2 ± 8.5 kg) performed a graded exercise test (GXT) and a lactate minimum test (LMT) to determine lactate threshold at 4 mmol L-1 (LT4 mmol L-1) and lactate minimum (LM), respectively. The agreement of both lactate thresholds concepts for constant load performance prediction (change of ≤ 1 mmol L-1 during the last 20 min) was evaluated within constant load tests (CLT; 30 min) at a power output (PO) corresponding to LT4 mmol L - 1 and LM. Oxygen uptake ( V . ⁢ O 2 ), respiratory exchange ratio (RER), heart rate (HR) and blood lactate (La) were measured during all tests. RESULTS: Power output at the corresponding thresholds (LT4 mmol L-1: 149 ± 34 W vs. LM: 137 ± 18 W) revealed no significant difference (p = 0.06). During the CLT at LT4 mmol ⋅ L -1 and LM, V . ⁢ O 2 , and RPE were not significantly different. However, LA, RER, and HR were significantly higher (p ≤ 0.02) during CLT at LT4 mmol L-1. Bland-Altman plots indicate a wide range of dispersion for all parameters between both lactate threshold concepts. Evaluations of LT4 mmol L-1 and LM did not meet the criteria for constant load performance within the CLT for 33 and 17% of the athletes, respectively. DISCUSSION: Both exercise tests and the corresponding lactate threshold concept revealed appropriate estimates to predict a steady state performance for the majority of participants. However, as PO determination at LT4 mmol L-1 and LM exceeds the criteria for constant load performance (increase of ≥ 1 mmol L-1) for 33 and 17% respectively the current results indicate the common criteria for constant load performance (change of ± 1 mmol L-1) might not be sufficiently precise for elite athletes in handcycling. Consequently, exercise test results of elite athletes should be analyzed individually and verified by means of several CLT.

The Lactate Minimum Test: Concept, Methodological Aspects and Insights for Future Investigations in Human and Animal Models.

In 1993, Uwe Tegtbur proposed a useful physiological protocol named the lactate minimum test (LMT). This test consists of three distinct phases. Firstly, subjects must perform high intensity efforts to induce hyperlactatemia (phase 1). Subsequently, 8 min of recovery are allowed for transposition of lactate from myocytes (for instance) to the bloodstream (phase 2). Right after the recovery, subjects are submitted to an incremental test until exhaustion (phase 3). The blood lactate concentration is expected to fall during the first stages of the incremental test and as the intensity increases in subsequent stages, to rise again forming a "U" shaped blood lactate kinetic. The minimum point of this curve, named the lactate minimum intensity (LMI), provides an estimation of the intensity that represents the balance between the appearance and clearance of arterial blood lactate, known as the maximal lactate steady state intensity (iMLSS). Furthermore, in addition to the iMLSS estimation, studies have also determined anaerobic parameters (e.g., peak, mean, and minimum force/power) during phase 1 and also the maximum oxygen consumption in phase 3; therefore, the LMT is considered a robust physiological protocol. Although, encouraging reports have been published in both human and animal models, there are still some controversies regarding three main factors: (1) the influence of methodological aspects on the LMT parameters; (2) LMT effectiveness for monitoring training effects; and (3) the LMI as a valid iMLSS estimator. Therefore, the aim of this review is to provide a balanced discussion between scientific evidence of the aforementioned issues, and insights for future investigations are suggested. In summary, further analyses is necessary to determine whether these factors are worthy, since the LMT is relevant in several contexts of health sciences.

Two water environment adaptation models enhance motor behavior and improve the success of the lactate minimum test in swimming rats

Abstract AIMS This study was designed to investigate the effects of 14 water environment adaptation days on motor behavior and physiological condition of swimming rats. METHODS Sixty male Wistar rats were divided into four groups-baseline (Bl) and control (Co) groups-which did not perform the water environment adaptation; and sub (SubAnT) and (SupraAnT) anaerobic threshold groups, which performed 14 water environment adaptation days with sub or supra anaerobic threshold progressive loads (from the tenth day), respectively. The climbing-swimming prevalence (i.e. motor behavior) was analyzed during the water environment adaptation days. Lactate minimum test (LMT) parameters and muscular/hepatic glycogen content in addition to serum creatine kinase were also measured. RESULTS Animals from SubAnT and SupraAnT groups presented a lower climbing-swimming pattern throughout the extent of the experiment (p=0.000), especially after the 5th session. These results were achieved without an improvement in the LMT results or glycogen/creatine kinase. In addition, improvements of 26.6% and 25% for the LMT success rate (i.e. LMT reliability) were obtained only for SubAnT and SupraAnT animals. CONCLUSION Overall, we demonstrated that a water environment adaptation period is necessary for lowering the climbing-swimming pattern without physiological improvement.(AU)

Estimation of the Maximal Lactate Steady State Intensity by the Rating of Perceived Exertion.

The maximal lactate steady state is the gold standard for evaluating aerobic capacity; however, it is time-consuming. The lactate minimum protocol is an easier alternative, but is not feasible and still expensive. This study investigated whether the rating of perceived exertion of 13 is an accurate predictor of lactate minimum and maximal lactate steady state intensities. Eleven physically active men performed three tests: (1) incremental exercise with workloads based on rating of perceived exertion of 10, 13, and 16 (experimental protocol - denominated RPE-13 test), (2) lactate minimum, and (3) maximal lactate steady state. No differences were observed among participants' workloads corresponding to rating of perceived exertion 13, lactate minimum, and maximal lactate steady state intensities. Thus, the workload associated with the rating of perceived exertion of 13 was equivalent to the other two protocols investigated.

Training Intensity Distribution and Changes in Performance and Physiology of a 2nd Place Finisher Team of the Race across America Over a 6 Month Preparation Period.

Aim: To monitor the training intensity distribution (TID) and the development of physiological and performance parameters. Methods: During their preparation period for the RAAM, 4 athletes (plus 1 additional backup racer) performed 3 testing sessions; one before, one after 3, and one after 6 months of training. VO2max, maximal rate of lactate accumulation (dLa/dtmax), critical power, power output at lactate minimum (MLSSP), peak and mean power output during a sprint test, heart rate recovery, isometric strength, jumping height, and body composition were determined. All training sessions were recorded with a power meter. The endurance TID was analyzed based on the time in zone approach, according to a classical 3-zone model, including all power data of training sessions, and a power specific 3-zone model, where time with power output below 50% of MLSSP was not considered. Results: The TID using the classical 3-zone model reflected a pyramidal TID (zone 1: 63 ± 16, zone 2: 28 ± 13 and zone 3: 9 ± 4%). The power specific 3-zone model resulted in a threshold-based TID (zone 1: 48 ± 13, zone 2: 39 ± 10, zone 3: 13 ± 4%). VO2max increased by 7.1 ± 5.3% (P = 0.06). dLa/dtmax decreased by 16.3 ± 8.1% (P = 0.03). Power output at lactate minimum and critical power increased by 10.3 ± 4.1 and 16.8 ± 6.2% (P = 0.01), respectively. No changes were found for strength parameters and jumps. Conclusion: The present study underlines that a threshold oriented TID results in only moderate increases in physiological parameters. The amount of training below 50% of MLSSp (~28% of total training time) is remarkably high. Researchers, trainers, and athletes should pay attention to the different ways of interpreting training power data, to gain realistic insights into the TID and the corresponding improvements in performance and physiological parameters.

Anaerobic and aerobic performances in elite basketball players.

THE PURPOSE OF THIS STUDY WAS TO PROPOSE A SPECIFIC LACTATE MINIMUM TEST FOR ELITE BASKETBALL PLAYERS CONSIDERING THE: Running Anaerobic Sprint Test (RAST) as a hyperlactatemia inductor, short distances (specific distance, 20 m) during progressive intensity and mathematical analysis to interpret aerobic and anaerobic variables. The basketball players were assigned to four groups: All positions (n=26), Guard (n= 7), Forward (n=11) and Center (n=8). The hyperlactatemia elevation (RAST) method consisted of 6 maximum sprints over 35 m separated by 10 s of recovery. The progressive phase of the lactate minimum test consisted of 5 stages controlled by an electronic metronome (8.0, 9.0, 10.0, 11.0 and 12.0 km/h) over a 20 m distance. The RAST variables and the lactate values were analyzed using visual and mathematical models. The intensity of the lactate minimum test, determined by a visual method, reduced in relation to polynomial fits (2nd degree) for the Small Forward positions and General groups. The Power and Fatigue Index values, determined by both methods, visual and 3rd degree polynomial, were not significantly different between the groups. In conclusion, the RAST is an excellent hyperlactatemia inductor and the progressive intensity of lactate minimum test using short distances (20 m) can be specifically used to evaluate the aerobic capacity of basketball players. In addition, no differences were observed between the visual and polynomial methods for RAST variables, but lactate minimum intensity was influenced by the method of analysis.

The response of the lactate minimum test to a 12-week swimming training / La respuesta del test de lactato mínimo de 12 semanas de entrenamiento de natación / Resposta do teste de lactato mínimo à 12 semanas de treinamento de natação

Despite the utilization of lactate minimum test (LMT) in training, its intensity response to training remains controversial. The aim of the present study was to verify alterations of LMT intensity in swimmers during a 12-week training protocol. Eight swimmers were submitted to three LMT assessments: beginning of the season, T0; after four, T4; and twelve weeks, T12. The LMT consisted of a 200m maximal effort and, after eight minutes of passive rest, five incremental stages of 200m swimming. The intensities of the incremental stages were defined subjectively ("very light," "light," "moderate," "hard," and "all-out"). The training was divided in two blocks of periodization: endurance training period (ETP, T0 - T4), and quality plus taper period (QTP, T4 - T12). The LMT intensity of T4 and T12 were significantly higher than T0. We conclude that LMT is modified due to swimming training and can be used for training prescription and detection of aerobic capacity alterations during a season...

"Resposta do teste de lactato mínimo à 12 semanas de treinamento de natação." Apesar da comum utilização do teste de lactate mínimo (LMT) no treinamento, a sensibilidade da sua intensidade permanece controversa. O objetivo do presente estudo foi verificar alterações da intensidade do LMT em nadadores durante 12 semanas de treinamento. Oito nadadores foram submetidos à três avaliações LMT: começo da temporada, T0; após quatro, T4; e doze semanas, T12. O LMT consistiu em nadar 200m em esforço máximo, e após oito minutos de repouso passivo, cinco estágios incrementais de 200m. As intensidades dos estágios incrementais foram definidas subjetivamente ("muito fraco," "fraco," "moderado," "forte" e "máximo"). O treinamento foi dividido em dois blocos de periodização: período de treinamento de endurance (ETP, T0 - T4), e período específico mais polimento (QTP, T4 - T12). A intensidade do LMT em T4 e T12 foi significantemente maior que T0. Concluímos que o LMT é modificado com o treinamento de natação e pode ser usado na prescrição de treinamento e detecção de alterações da capacidade aeróbia durante a temporada...

"La respuesta del test de lactato mínimo de 12 semanas de entrenamiento de natación." A pesar de la utilización de lo test de lactato mínimo (LMT) en el entrenamiento, la respuesta de su intensidad sigue siendo controvertido. El objetivo de este estudio fue investigar los cambios en la intensidad de LMT en nadadores durante 12 semanas de entrenamiento. Ocho nadadores fueron sometidos a tres evaluaciones LMT: comienzo de la temporada, T0; después de las cuatro, T4; y doce semanas T12. El LMT consistió en 200m natación de máximo esfuerzo, y después de ocho minutos de descanso pasivo, cinco etapas incrementales de 200m. Las intensidades de las fases incrementales fueron definidos subjetivamente ("muy débil," "débil," "moderada," "fuerte" y "máxima"). La formación se dividió en dos bloques de periodización: período de entrenamiento de endurance (ETP, T0 - T4), y período específico más pulido (QTP, T4 - T12). La intensidad del LMT en T4 y T12 fue significativamente mayor que T0. Concluimos que el LMT es modificado con el entrenamiento de natación y puede ser utilizado en la prescripción de al entrenamiento y la detección de cambios en la capacidad aeróbica durante la temporada...

Effects of maximum intensity aerobic swimming exercise until exhaustion at different times of day on the hematological parameters in rats.

The aims of this study were: a) to analyze the time of day effect on the aerobic capacity and time to exhaustion at aerobic capacity intensity (TE), and b) to analyze the physiological impact of handling and exercise testing during the light and dark periods, based on hematological parameters. Eighty rats were randomly divided into two control groups (C12 and C20) and two exercise groups (E12 and E20), assessed at 12:00 h (C12 and E12) or 20:00 h (C20 and E20). The lactate minimum intensity (LMi) was measured and after 48 h the exercise groups were subjected to a bout of swimming until exhaustion at LMi (TE). The TE was 1.30 ± 0.51 h for the E12 group and 1.81 ± 0.77 h for the E20 group (p = 0.03). The time of day effect was significant for all white blood cell counts (12:00 h > 20:00 h). Chronic handling and performing exercise tests at 12:00 h (light period) resulted in an increased WBC counts and decreased exercise tolerance. The favorable time of day for aerobic capacity and performance assessment and hematological parameters was at 20:00 h (dark period), which is associated with the wakefulness period of the assessed animals.

Adaptação de protocolos invasivos e não invasivos para avaliações aeróbias e anaeróbias específicas ao basquetebol feminino / Adaptation of invasive and non-invasive protocols to aerobic and anaerobic specific evaluation in female basketball players

OBJETIVO: Adaptar os protocolos de velocidade crítica (Vcrit), RAST Test e Lactato Mínimo (LM) à especificidade do basquetebol feminino. MÉTODOS: Doze basquetebolistas bem treinadas (19 ± 1 anos) foram avaliadas pelo modelo velocidade crítica, composto por quatro intensidades (10,8, 12,0, 13,0, 14,5 km/h) de corridas "vai-vem" até exaustão, aplicadas em dias alternados. O modelo linear 'velocidade versus 1/tlim' foi adotado para determinação de parâmetros aeróbio (Vcrit) e anaeróbio (CCA). O LM foi composto por duas fases: 1) indução hiperlactacidêmica, caracterizada pelo RAST adaptado, e 2) fase progressiva, composta por cinco estágios de 3 minutos em corridas "vai-vem" de 20 m (7 a 12km/h), com coletas de sangue ao final de cada estágio. RESULTADOS: A velocidade (vLM) e a concentração do lactato mínimo foram obtidas pelos ajustes polinomiais 'lactato versus intensidade' (LM1) e 'lactato versus tempo' (LM2). A ANOVA one-way, teste t-Student e correlação de Pearson foram utilizados na análise estatística. A Vcrit foi obtida a 10,3 ± 0,2 km/h e a CCA estimada em 73,0 ± 3,4 m. O RAST foi capaz de induzir a hiperlactacidemia e determinar potências máxima (3,6 ± 0,2 W/kg), média (2,8 ± 0,1 W/kg), mínima (2,3 ± 0,1W/kg) e o índice de fadiga (30 ± 3%). A vLM1 e vLM2 foram obtidas, respectivamente, a 9,47 ± 0,13 e 9,8 ± 0,13km/h, sendo a vLM1 menor que a Vcrit. CONCLUSÕES: Os resultados sugerem que o modelo específico não invasivo pode ser utilizado para determinar parâmetros aeróbios e anaeróbios de basquetebolistas e, assim como em outras modalidades, a Vcrit superestima as intensidades de LM. Além disso, a adaptação do LM ao basquetebol feminino utilizando o RAST e a fase progressiva em exercício "vai-vem" foi efetiva para avaliar as atletas respeitando a especificidade da modalidade, com elevado percentual de sucesso no ajuste polinomial 'lactato versus tempo'.

OBJECTIVE: To adapted the critical velocity (CV), RAST test and lactate minimum (LM) to evaluation of female basketball players. METHODS: Twelve well-trained female basketball players (19 ± 1yrs) were submitted to four intensities running (10 - 14 km/h) at shuttle exercise until exhaustion, applied on alternate days. The linear model 'velocity vs. 1/tlim' was adopted to determine the aerobic (CV) and anaerobic (CCA) parameters. The lactate minimum test consisted of two phases: 1) hiperlactatemia induction using the RAST test and 2) incremental test composed by five shuttle run (20-m) at 7, 8, 9, 10, and 12 km/h. Blood samples were collected at the end of each stage. RESULTS: The velocity (vLM) and blood lactate concentration at LM were obtained by two polynomial adjustments: lactate vs. intensity (LM1) and lactate vs. time (LM2). ANOVA one-way, Student t-test and Pearson correlation were used for statistical analysis. The CV was obtained at 10.3 ± 0.2 km/h and the CCA estimated at 73.0 ± 3.4 m. The RAST was capable to induce the hiperlactatemia and to determine the Pmax (3.6 ± 0.2 W/kg), Pmed (2.8 ± 0.1 W/kg), Pmin (2.3 ± 0.1 W/kg) and FI (30 ± 3%). The vLM1 and vLM2 were obtained, respectively, at 9.47 ±0.13 km/h and 9.8 ± 0.13 km/h, and CV was higher than vLM1. CONCLUSION: The results suggest that the non-invasive model can be used to determine the aerobic and anaerobic parameters. Furthermore, the LM test adapted to basketball using RAST and progressive phase was effective to evaluate female athletes considering the specificity of modality, with high success rates observed in polynomial adjustment 'lactate vs. time' (LM2).

Comparação entre ergômetros específico e convencionais na determinação da capacidade aeróbia de mesatenistas / Comparison between specific and conventional ergometers in the aerobic capacity determination in table tennis players

O objetivo deste estudo foi verificar a necessidade de utilizar protocolo específico para avaliar a capacidade aeróbia de mesatenistas, comparando os testes aplicados em ergômetro específico com ergômetros convencionais. Para isso, nove mesatenistas foram os participantes do estudo (18,22 ± 2,33 anos; altura de 1,76 ± 0,09m; massa corporal de 67,36 ± 10,03kg; gordura corporal de 14,74 ± 6,69 por cento; e índice de massa corporal (IMC) de 21,69 ± 2,71kg/m²). Foram aplicados os testes de lactato mínimo, realizados no ergômetro de braço (LACmin braço) e no cicloergômetro (LACmin ciclo) (ergômetros convencionais) e o teste de limiar anaeróbio em procedimento específico para o tênis de mesa (LAn espec) utilizando um lançador de bolas mecânico como ergômetro. Como procedimentos estatísticos foram utilizados o teste de análise de variância (ANOVA) one way e o teste de correlação produto-momento, com nível de significância de 5 por cento. O LAn espec (48,11 ± 6,82 bolas.min-1) não foi significativamente correlacionado com a intensidade de LACmin braço (91,94 ± 11,51W) (r = 0,18; p = 0,72); e apresentou correlação negativa com a intensidade de LACmin ciclo (157,97 ± 12,51W) (r = - 0,80; p = 0,02). Desse modo, os resultados encontrados no estudo levam a concluir que existe necessidade do uso de protocolo específico para mensurar a capacidade aeróbia no tênis de mesa.

The aim of this study was to verify the necessity to use a specific protocol for evaluating the aerobic capacity in table tennis players, comparing the tests applied in conventional ergometers with test applied in specific ergometer. Nine table tennis players were participants in the study (18.22 ± 2.33 years; 1.76 ± 0.09 m of height; 67.36 ± 10.03 Kg of body mass; 14.74 ± 6.69 percent of fat mass and 21.69 ± 2.71 Kg/m² of body mass index). The participants performed lactate minimum tests in the arm ergometer and cycle ergometer; in addition to incremental test in specific ergometer for determination of the anaerobic threshold (AnTspec) through visual inspection. Statistical procedures used Analysis of Variance test (one-way ANOVA) and the Pearson correlation test, with level of significance of 5 percent. There was not significant correlation between the AnTspec (48.11 ± 6.82 shots.min-1) and the lactate minimum intensity obtained in arm ergometry (91.94 ± 11.51 W) (r=0.18; p=0.72). The lactate minimum intensity in cycle ergometer (157.97 ± 12.51 W) presented significant correlation with the AnTspec (r=-0.80; p=0.02), but a negative correlation was verified. Therefore, a specific protocol is needed for measuring the aerobic capacity in table tennis.

Correlações entre protocolos de determinação do limiar anaeróbio e o desempenho aeróbio em nadadores adolescentes / Correlations between anaerobic threshold determination protocols and aerobic performance in adolescent swimmers

O objetivo do presente estudo foi correlacionar as velocidades de limiar anaeróbio (LAn) obtidas a partir de concentrações fixas de lactato (VLAn 4 e VLAn 3,5mM), velocidade de lactato mínimo (VLac min) e velocidade crítica (VC) determinada a partir de diferentes distâncias e número de coordenadas: VC1 (50/100/200m), VC2 (100/200/400m), VC3 (50/100/200/400m) e VC4 (200/400m) com o desempenho nos 400m(s) em nadadores adolescentes. Fizeram parte da amostra 15 nadadores (10 meninos e cinco meninas = 14,7 ± 0,7 anos; 61,9 ± 8,5kg; 171,1 ± 8,8cm) de nível nacional, com experiência entre cinco e sete anos na natação competitiva. Para análise das correlações entre os índices e o desempenho nos 400m(s) foi utilizado o coeficiente de correlação de Pearson. O nível de significância adotado foi de p < 0,01. As correlações entre a VLAn 4mM, VLAn 3,5mM, VLac min e o desempenho nos 400m(s) foram de r = -0,63, r = -0,90 e r = -0,91, respectivamente (p < 0,01). As correlações entre a VC1 (50/100/200m), VC2 (100/200/400m), VC3 (50/100/200/400m), VC4 (200/400m) e o desempenho nos 400m(s) foram: r = -0,62, r = -0,97, r = -0,98 e r = -0,94, respectivamente (p < 0,01). Sugere-se que o LAn determinado a partir da concentração fixa de lactato de 3,5mM, bem como a VLac min e a VC obtidas por meio de distâncias maiores parecem ser os mais adequados índices preditores do desempenho aeróbio nos nadadores adolescentes estudados. Além disso, o número de coordenadas parece não influenciar a relação entre a VC e desempenho aeróbio.

The purpose of this study was to correlate the anaerobic threshold speeds (ATS) obtained from fixed lactate blood concentration (ATS 4 e ATS 3.5 mM), lactate minimum speed (Lac minS) and the critical speed (CS) determined from different distances and number of coordinates: CS1 (50/100/200 m), CS2 (100/200/400 m), CS3 (50/100/200/400 m) and CS4 (200/400 m) with the performance in 400 meters (s) in adolescent swimmers. The sample was constituted by 15 swimmers (10 boys and five girls = 14.7 ± 0.7 years; 61.9 ± 8.5 kg; 171.1 ± 8.8 cm) of national level, with five to seven years of experience in competitive swimming. The correlation between the indexes and the performance in 400 m (s) was made using Pearson correlation coefficients. Significance was set at p < 0.01. The correlations between ATS 4 mM, ATS 3.5 mM, Lac minS and the performance in 400 m (s) were: r = -0.63, r = -0.90 e r = 0.91, respectively (p < 0.01). The correlations between CS1 (50/100/200 m), CS2 (100/200/400 m), CS3 (50/100/200/400 m), CS4 (200/400 m) and the performance in 400 m (s) were: r = -0.62, r = -0.97, r = -0.98 e r = -0.94, respectively (p < 0.01). We suggest that ATS obtained from fixed lactate blood concentration of 3.5 mM, as well as Lac minS and the CS obtained through larger distances seem to be the most fitted indexes of prediction of the aerobic performance in the studied adolescent swimmers. Additionally, the number of coordinates seems no influencing the relation between CS and aerobic performance.