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ABSTRACT Introduction: Traditional intermittent hypoxia training improves sport performance after short periods of exposure, but acute exposure to intermittent hypoxia leads to decreased training intensity and technical quality. The solution to overcome these negative effects may be to perform efforts in normoxia and the intervals between efforts in hypoxia, maintaining the quality of training and the benefits of hypoxia. Objective: This study aimed to evaluate the acute physiological responses to hypoxia exposure during recovery between high intensity efforts. Materials and methods: Randomized, one-blind, placebo-controlled study. Sixteen men performed a graded exercise test to determine their maximal intensity and two sessions of high-intensity interval training. The training intervals could be in hypoxia (HRT), FIO2: 0.136 or normoxia (NRT), FIO2: 0.209. During the two-minute interval between the ten one-minute efforts, peripheral oxygen saturation (SpO2), heart rate (HR), blood lactate ([La]), blood glucose ([Glu]) were constantly measured. Results: There were differences in HR (TRN = 120 ± 14 bpm; TRH = 129 ± 13 bpm, p < 0.01) and SpO2 (TRN = 96.9 ± 1.0%; TRH = 86.2 ± 3.5%, p < 0.01). No differences in [La] and [Glu] TRN (4.4 ± 1.7 mmol.l-1; 3.9 ± 0.5 mmol.l-1) and TRH (5.2 ± 2.0 mmol.l-1; 4.0 ± 0.8 mmol.l-1, p = 0.17). Conclusion: The possibility of including hypoxia only in the recovery intervals as an additional stimulus to the training, without decreasing the quality of the training, was evidenced. Level of Evidence II; Randomized Clinical Trial of Minor Quality.

RESUMEN Introducción: El entrenamiento tradicional en hipoxia intermitente mejora el rendimiento deportivo tras cortos periodos de exposición, sin embargo, la exposición aguda a la hipoxia intermitente conduce a una disminución de la intensidad del entrenamiento y de la calidad técnica. La solución para superar estos efectos negativos puede ser realizar los esfuerzos en normoxia y los intervalos entre esfuerzos en hipoxia, manteniendo la calidad del entrenamiento y los beneficios de la hipoxia. Objetivo: Este estudio pretendía evaluar las respuestas fisiológicas agudas a la exposición a la hipoxia durante la recuperación entre esfuerzos de alta intensidad. Materiales y métodos: Estudio aleatorizado, a ciegas y controlado con placebo. Dieciséis hombres realizaron una prueba de ejercicio graduado para determinar su intensidad máxima y dos sesiones de entrenamiento por intervalos de alta intensidad. Los intervalos de entrenamiento podían ser en hipoxia (HRT), FIO2: 0,136 o normoxia (NRT), FIO2: 0,209. Durante el intervalo de dos minutos entre los diez esfuerzos de un minuto, se midieron constantemente la saturación periférica de oxígeno (SpO2), la frecuencia cardiaca (FC), el lactato en sangre ([La]) y la glucemia ([Glu]). Resultados: Hubo diferencias en la FC (TRN = 120 ± 14 lpm; TRH = 129 ± 13 lpm, p < 0,01) y la SpO2 (TRN = 96,9 ± 1,0%; TRH = 86,2 ± 3,5%, p < 0,01). No hubo diferencias en [La] y [Glu] TRN (4,4 ± 1,7 mmol.l-1; 3,9 ± 0,5 mmol.l-1) y TRH (5,2 ± 2,0 mmol.l-1; 4,0 ± 0,8 mmol.l-1, p = 0,17). Conclusión: Se evidenció la posibilidad de incluir hipoxia sólo en los intervalos de recuperación como estímulo adicional al entrenamiento sin disminuir la calidad del mismo. Nivel de Evidencia II; Ensayo Clínico Aleatorizado de Baja Calidad.

RESUMO Introdução: O treinamento de hipóxia intermitente tradicional melhora o desempenho esportivo após curtos períodos de exposição, porém a exposição aguda à hipóxia intermitente leva à diminuição da intensidade do treinamento e da qualidade técnica. A solução para superar esses efeitos negativos pode ser realizar esforços em normóxia e os intervalos entre os esforços em hipóxia, mantendo a qualidade do treinamento e os benefícios da hipóxia. Objetivo: Este estudo teve como objetivo avaliar as respostas fisiológicas agudas à exposição de hipóxia durante a recuperação entre esforços de alta intensidade. Materiais e métodos: Estudo aleatório e one-blinded, com efeito placebo controlado. Dezesseis homens realizaram um teste de exercício graduado para determinar sua intensidade máxima e duas sessões de treinamento intervalado de alta intensidade. Os intervalos de treinamento podem ser em hipóxia (TRH), FIO2: 0,136 ou normóxia (TRN), FIO2: 0,209. Durante os dois minutos de intervalo entre os dez esforços de um minuto, foram medidos constantemente a saturação periférica de oxigênio (SpO2), frequência cardíaca (FC), lactato sanguíneo ([La]), glicemia ([Glu]). Resultados: Houve diferenças na FC (TRN = 120 ± 14 bpm; TRH = 129 ± 13 bpm, p <0,01) e SpO2 (TRN = 96,9 ± 1,0%; TRH = 86,2 ± 3,5%, p <0,01). Sem diferenças em [La] e [Glu] TRN (4,4 ± 1,7 mmol.l-1; 3,9 ± 0,5 mmol.l-1) e TRH (5,2 ± 2,0 mmol.l-1; 4,0 ± 0,8 mmol.l-1, p = 0,17). Conclusão: Evidenciou-se a possibilidade de incluir a hipóxia apenas nos intervalos de recuperação como um estímulo adicional ao treinamento, sem diminuir a qualidade do treinamento. Nível de Evidência II; Estudo Clínico Randomizado de Menor Qualidade.

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Iron restriction during pregnancy can lead to iron deficiency and changes in the dopaminergic system in the adulthood of offspring, and restless legs syndrome (RLS) is closely related to these changes. Objectives: Analyze whether iron restriction during pregnancy would cause changes in the behavior, sleep, and dopaminergic system of the male offspring. In addition, we aimed to assess whether exercise would be able to modulate these variables. The pregnant rats (Wistar) were divided into four groups with different concentrations of iron in the diet: standard (St), supplementation (Su), restriction since weaning (R1), and restriction only during pregnancy (R2). After birth, the offspring were assigned to their respective groups according to the dams diet (St, Su, R1, and R2) and distributed into sedentary (SD) and exercised (EX) (for 8 weeks of training), reaching eight groups of offspring (O): OSt SD, OSt EX, OSu SD, OSu EX, OR1 SD, OR1 EX, OR2 SD, and OR2 EX. Sleep, behavior, and analysis of key genes of dopaminergic system (D2, DAT) were performed after 8 weeks. The results for trained offspring that the mother received supplementation diet were the most expressive, with increased freezing and the OR1 SD group showed an increase in DAT protein content. These changes may have been due to the association between the dams diet during pregnancy and the practice of exercise by the offspring. The different concentrations of iron during pregnancy caused changes in the offspring, however, they were not associated with fetal programming in the context of RLS.

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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.

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Regular physical exercise has been described as a good strategy for prevention or reduction of musculoskeletal pain. The Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) has been investigated as a promising target for the control of inflammatory pain. Therefore, the aim of this study was to evaluate whether activation of PPARγ receptors is involved in the reduction of acute muscle pain by chronic exercise and, in this case, whether this process is modulated by inflammatory cytokines. To this end, Wistar rats were submitted to swimming physical training for a period of 10 weeks, 5 days per week, 40 min/day, in an intensity of 4% of the body mass. Muscle hyperalgesia was measured by Randall Selitto test and pro-inflammatory cytokines were quantified by ELISA. The results showed that swimming physical training prevented the onset of acute mechanical muscle hyperalgesia and the increase in muscle levels of Cytokine-induced neutrophil chemoattractant 1 (CINC-1) induced by carrageenan into gastrocnemius muscle. In addition, local pre-treatment with the selective PPARγ receptors antagonist GW9662 reversed the mechanical muscle hypoalgesia and the modulation of CINC-1 levels induced by swimming physical training. These data suggest that swimming physical training prevented the onset of acute mechanical muscle hyperalgesia by a mechanism dependent of PPARγ receptors, which seems to contribute to this process by modulation of the pro-inflammatory cytokine CINC-1, and highlight the potential of PPARγ receptors as a target to control musculoskeletal pain and to potentiate the reduction of musculoskeletal pain induced by exercise.

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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.

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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)

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Although aerobic training has been shown to affect the lactate transport of skeletal muscle, there is no information concerning the effect of continuous aerobic training on spontaneous physical activity (SPA). Because every movement in daily life (i.e., SPA) is generated by skeletal muscle, we think that it is possible that an improvement of SPA could affect the physiological properties of muscle with regard to lactate transport. The aim of this study was to evaluate the effect of 12 weeks of continuous aerobic training in individualized intensity on SPA of rats and their gene expressions of monocarboxylate transporters (MCT) 1 and 4 in soleus (oxidative) and white gastrocnemius (glycolytic) muscles. We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT). Sixty-day-old rats were randomly divided into three groups: a baseline group in which rats were evaluated prior to initiation of the study; a control group (Co) in which rats were kept without any treatment during 12 weeks; and a chronic exercise group (Tr) in which rats swam for 40 min/day, 5 days/week at 80% of anaerobic threshold during 12 weeks. After the experimental period, SPA of rats was measured using a gravimetric method. Rats had their expression of MCTs determined by RT-PCR analysis. In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties. Changes in SPA were concomitant with changes in MCT1 expression in the soleus muscle of trained rats, suggestive of an additional adaptive response toward increased lactate clearance. This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT). We propose an approach to combat the decline of SPA of rats in their home cages. This new finding is worth for scientists who work with animal models to study the protective effects of exercise.

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Abstract The use of saliva may assist an emerging need for cost, time and invasiveness reduction, and special care involved in the collection of biomarkers, compared to blood tests. The aim of this study was to analyze the lactate kinetics in blood and saliva in response to graded cycle ergometer exercise. In a predictive correlational study, nine healthy male cyclists (24±2 years; 71.3±7.6kg; 170.9±4.7cm) were submitted to a graded exercise protocol, started at 10% of maximal workload (WMAX). Blood and salivary lactate concentrations were measured every 3 minutes during exercise and at the 3rd, 6th, 9th, 15th, 30th and 60th minutes after exercise. To investigate the relationship between salivary and blood lactate, linear regression analysis was applied and the level of significance was set at p<0.05. There was a parallel evolution among the mean values of lactate measured in capillary blood and saliva with increasing workload (R2adjust. = 0.93, p<0.001). It was concluded that although with different magnitudes, the lactate response during incremental exercise was similar between blood and saliva. Thus, the use of salivary lactate seems to be a noninvasive model for determining the blood lactate response to graded cycle ergometer exercise.

Resumo O emprego da saliva pode subsidiar uma necessidade emergente de redução de custos, invasividade, cuidados e tempo, comparado às análises sanguíneas. O objetivo do estudo foi analisar a cinética do lactato no sangue e saliva, em resposta ao exercício físico incremental em cicloergômetro. Em uma pesquisa correlacional preditiva, nove ciclistas saudáveis do sexo masculino (24±2 anos; 71.3±7.6kg; 170.9±4.7cm) foram submetidos a um protocolo de esforço progressivo, iniciado a 10% da carga máxima (WMÁX), obtida previamente, com incremento de 10% a cada três minutos até a exaustão voluntária. A concentração de lactato sanguíneo e salivar foi medida durante o exercício e no 3º, 6º, 9º, 15º, 30º e 60º minutos pós-exercício. Para averiguar relações entre as curvas de lactato, foi realizada uma análise de regressão linear. Verificou-se uma evolução paralela entre os valores médios de lactato, medidos no sangue capilar e na saliva, com o aumento da carga de trabalho (R2ajust. =0.93; p<0.001). Conclui-se que, embora com magnitudes diferentes, a resposta lactacidêmica, durante o exercício incremental, foi similar entre o sangue e a saliva. Nesse sentido, o uso do lactato salivar demostrou ser um modelo não invasivo para a determinação do lactato sanguíneo em resposta ao exercício físico.

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O estudo objetivou propor um teste específico para identificar o limiar anaeróbio (Lan) em atletas de canoagem slalom. O Lan foi determinado por teste progressivo até a exaustão nas velocidades de 5,6,7,8,9 e 9,5km/h, realizado em lagoa onde comumente eram realizados os treinos. O Lan foi obtido por dois métodos matemáticos: inspeção visual e bissegmentação da curva lactacidêmica (LanBI), e utilização das concentrações fixas de lactato 4mM e 2,5mM (LanOBLA). O LanBI e LanOBLA foram analisados por Anova One-Way e correlação de Pearson (p<0,05). O LanBI foi obtido em 6,98 ± 0,16 km/h, a 2,53±0,25mM, e o Lan OBLA 4,0 ocorreu em 7,80±0,21km/h, superestimando em 11,5% o LanBI.. Desse modo, é possível determinar o Lan por teste específico para canoístas e, se adotado o OBLA, a concentração 2,5mM parece ser mais adequada à modalidade.

The study aimed to suggest a specific anaerobic threshold test (AT) to slalom kayak athletes. The AT was determined by progressive kayak exercise (5.0, 6.0, 7.0, 8.0, 9.0 e 9.5km/h) until exhaustion. Two mathematical methods were used: visual inspection and the bi-segmental lactate kinetics (ATi) and by fixed lactate concentration at 4mM (ATobla) and 2.5mM. The ATi and AToblawere compared by ANOVA One-Way and Pearson correlation (p<0.05). The ATi was obtained in 6.98±0.16Km/h, at 2.53±0.25mM and the ATobla 4.0 was 6.95±0.28Km/h, at intensity 11,5% higher than ATi. In this way, it is possible to determine the AT using a specific test to slalom kayak and, if adopted the OBLA, the 2.5mM blood concentration seems to be applicable to slalom kayak athletes.

El estudio tuvo como objetivo sugerir un test específico para determinar el umbral anaeróbico (UA) en atletas de canotaje slalom. El UA se determinó mediante un test progresivo hasta el agotamiento (5.0; 6.0; 7.0; 8.0; 9.0 y 9.5 km/h). Dos métodos matemáticos se utilizaron para identificar el UA: Inspección visual y bissegmentação de las curvas de lactato (UABI) y concentración fija de lactato em 4mM y 2.5mM (UAOBLA). El UAOBLA y UABI se analizaron por La Anova One-Wayt y por correlación de Pearson (p <0.05). El UABI se obtuvieron 6.98 ± 0.16 km/h, a 2.53 ± 0.25 mMy La UAOBLAfue 7.80 ± 0.21km/h, 11,5% mayor que UABI. Así, és posible determinar el UA en test especifico para canotaje y, si la opción for por el metodo OBLA, la concentración 2.5mM parece ser mas aplicable a atletas de canotaje slalom.

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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).