Effect of Swimming at Low Temperature on Uncoupling Protein Gene Expression in Skeletal Muscle of Wistar Rats / Efecto de la Natación a Baja Temperatura sobre la Expresión del Gen de la Proteína de Desacoplamiento en el Músculo Esquelético de Ratas Wistar

SUMMARY: As the economy develops and living standards improve, overweight and obesity are increasingly prevalent. Currently, weight-loss medications are primarily administered orally or intravenously, which can result in poor targeting, low bioavailability, frequent administration, and high toxicity and side effects. The study aimed to address these challenges by preparing polylactic acid- polyethylene glycol staple fibers that carry the browning drug pioglitazone hydrochloride using electrostatic spinning and freeze-cutting techniques. Animal experiments were conducted to test the effectiveness of these fibers. Additionally, the study investigated the expression of uncoupling protein genes in rats exposed to different water temperatures by measuring changes in serum urea nitrogen and mRNA expression levels of skeletal muscle uncoupling protein genes. The physiological and genetic effects of low-temperature swimming exercise on changes in energy metabolism in rats were also analyzed at both the individual and molecular levels. The results revealed that serum urea nitrogen remained more stable in hypothermic swimming rats compared to rats in the swimming group. Furthermore, the study observed an induced up-regulation of uncoupling proteins in the skeletal muscle of Wistar rats in response to external temperature stimulation, and the expression of mRNA for skeletal muscle uncoupling proteins significantly increased as the temperature decreased. And the prepared short nanofibers also had a significant promotive effect on uncoupling protein gene, COX7A1, while suppressing the expression of lipogenic gene.

A medida que la economía se desarrolla y los niveles de vida mejoran, el sobrepeso y la obesidad son cada vez más frecuentes. Actualmente, los medicamentos para bajar de peso se administran principalmente por vía oral o intravenosa, lo que puede resultar en una mala focalización, baja biodisponibilidad, administración frecuente y alta toxicidad y efectos secundarios. El estudio tuvo como objetivo abordar estos desafíos mediante la preparación de fibras cortadas de ácido poliláctico y polietilenglicol que transportan el fármaco pardo clorhidrato de pioglitazona mediante técnicas de hilado electrostático y liofilización. Se realizaron experimentos con animales para probar la eficacia de estas fibras. Además, el estudio investigó la expresión de genes de proteínas desacopladoras en ratas expuestas a diferentes temperaturas del agua midiendo los cambios en el nitrógeno ureico sérico y los niveles de expresión de ARNm de genes de proteínas desacopladoras del músculo esquelético. También se analizaron los efectos fisiológicos y genéticos del ejercicio de natación a baja temperatura sobre los cambios en el metabolismo energético en ratas, tanto a nivel individual como molecular. Los resultados revelaron que el nitrógeno ureico sérico permaneció más estable en ratas nadadoras hipotérmicas en comparación con las ratas del grupo de natación. Además, el estudio observó una regulación positiva inducida de las proteínas desacopladoras en el músculo esquelético de ratas Wistar en respuesta a la estimulación de la temperatura externa, y la expresión de ARNm para las proteínas desacopladoras del músculo esquelético aumentó significativamente a medida que disminuía la temperatura. Además, las nanofibras cortas preparadas también tuvieron un efecto promotor significativo sobre el gen de la proteína de desacoplamiento, COX7A1, al tiempo que suprimieron la expresión del gen lipogénico.

Nandrolone decanoate impairs gastrointestinal motility and duodenal morphometry in moderately exercised rats

The misuse of anabolic androgenic steroid associated or not with physical workouts disrupts gastrointestinal (GI) function homeostasis. Our goal was to investigate the effects of nandrolone decanoate (ND) and moderate swimming on the GI transit of solid meals, GI motor contractility, and intestinal histology in rats. Male Wistar rats were allocated to four groups that received intramuscular injections of ND (5.0 mg/kg) or vehicle (60.0 µL) and were submitted or not to swimming sessions (60 min, 5% body weight overload) for 4 weeks. Gastric emptying, intestinal transit, in vitro GI contractility, intestinal morphometry, and duodenal mucosal mast cells were evaluated in all experimental groups. ND treatment accelerated gastric emptying, slowed small intestine transit time, enhanced gastric carbachol-mediated reactivity, decreased crypt depth and villus height, reduced mucosal thickness, and increased the circular and longitudinal muscle layer thickness of the duodenum in sedentary rats. Moderate exercise accelerated intestinal transit time and reduced submucosa thickness. In vehicle-treated animals, a strong negative correlation was found between intestinal transit and mucosal mast cells, which was reversed by ND treatment. Combining ND treatment and swimming accelerated gastric emptying, increased duodenal cholinergic reactivity, inhibited the sodium nitroprusside relaxing response, increased the number of duodenal mast cells, decreased villus height, and increased the thickness of all muscle layers. ND changed the morphological and functional properties of the GI tract over time, with intense dysmotility, especially in sedentary animals, but moderate exercise seemed to have played a compensatory role in these harmful effects in the gut.

Cartilage protective effect of swimming exercise in aged mice with knee osteoarthritis / 中国组织工程研究

BACKGROUND:Swimming is an important non-pharmacological treatment for knee osteoarthritis,which can effectively alleviate the disease.However,the effect and mechanism of swimming on senile knee osteoarthritis are still unclear. OBJECTIVE:To investigate the effect of swimming exercise on the articular cartilage of aged mice with knee osteoarthritis. METHODS:Six 3-month-old male C57BL/6 mice were selected as the young group,and twelve 18-month-old male C57BL/6 mice were randomized into the aged group and the swimming group,with six mice in each group.Mice in the swimming group received adaptive swimming for 1 week and formal swimming for 8 weeks.After the intervention,stride length analysis and sampling were performed in each group.The total number of leukocytes and lymphocytes in peripheral blood was detected by blood routine examinations.The morphology of the articular cartilage was observed by hematoxylin-eosin and safranin O-fast green staining.Chondrocyte counts and the modified Mankin's score were used to evaluate the degree of articular cartilage damage.The protein and mRNA expressions of type Ⅱ collagen,aggrecan and matrix metalloproteinase 13 in articular cartilage were detected by immunohistochemical staining and RT-qPCR. RESULTS AND CONCLUSION:Compared with the young group,the mice in the aged group showed significantly decreased stride length(P＜0.05),significantly increased numbers of peripheral leukocytes and lymphocytes(P＜0.05),significantly decreased count of chondrocytes(P＜0.05),significantly increased modified Mankin's score(P＜0.05),significantly decreased protein and mRNA expression of type Ⅱ collagen and aggreca(P＜0.05),and significantly increased matrix metalloproteinase 13 expression(P＜0.05).Moreover,hematoxylin-eosin and safranin O-fast green staining showed the uneven surface of the articular cartilage,abnormal chondrocytes,and proteoglycan loss in the aged group.Compared with the aged group,swimming exercise significantly improved the stride length of mice(P＜0.05),decreased the count of peripheral blood lymphocytes(P＜0.05),increased the count of chondrocytes(P＜0.05),decreased the modified Mankin's score(P＜0.05),increased the protein and mRNA expression of type Ⅱ collagen and aggrecan(P＜0.05),and decreased the expression of matrix metalloproteinase 13(P＜0.05).Hematoxylin-eosin and safranin O-fast green staining showed that the articular surface of mice in the swimming group was smooth,chondrocytes were normal,and proteoglycan loss was less.All these findings indicate that swimming exercise can reduce the number of inflammatory cells in the blood of aged mice,improve articular chondrocytes,matrix composition and cartilage tissue morphology;thus,it has a protective effect on the cartilage of aged mice with knee osteoarthritis.

Promovendo experiências significativas por meio da natação: um autoestudo / Promoting meaningful experiences through swimming: a self-study / Promoción de experiencias significativas a través de la natación: un autoestudio

O presente estudo tem como objetivo explorar as experiências de uma graduanda de Educação Física na promoção de experiências significativas por meio da natação. Foi realizado um autoestudo por uma estagiária de natação e seu amigo crítico, um professor com titulação de mestre com ampla experiência no ensino da natação. Para a coleta de dados, foram utilizadas múltiplas fontes: Mensagens de WhatsApp, E-mails, documentos de planejamento e conversas informais. A análise dos dados foi por meio da técnica de análise de conteúdo, com as categorias determinadas a posteriori. As experiências da graduanda foram descritas em três categorias: comparação entre a abordagem tradicional e da abordagem para a promoção da experiência significativa, experiências de intervenção nas aulas e reflexões finais. Conclui-se que para promover experiências significativas por meio da natação é necessário incluir a diversão, a interação social, o desafio e a aprendizagem pessoalmente relevante.

The present study aims to explore the experiences of a Physical Education ungraduate in promoting meaningful experiences through swimming. A self-study was carried out by a swimming intern and her critical friend, a teacher with a master's degree with extensive experience in teaching swimming. For data collection, multiple sources were used: WhatsApp messages, E-mails, planning documents and informal conversations. Data analysis was performed using the content analysis technique, with the categories determined a posteriori. The undergraduate student's experiences were described in three categories: comparison between the traditional approach and the approach to promoting meaningful experience, intervention experiences in classes and final reflections. It is concluded that to promote meaningful experiences through swimming it is necessary to include fun, social interaction, challenge and personally relevant learning.

El presente estudio tiene como objetivo explorar las experiencias de un licenciado en Educación Física en la promoción de experiencias significativas a través de la natación. Un autoestudio fue realizado por una pasante de natación y su amiga crítica, una docente con maestría y amplia experiencia en la enseñanza de la natación. Para la recolección de datos se utilizaron múltiples fuentes: mensajes de WhatsApp, correos electrónicos, documentos de planificación y conversaciones informales. El análisis de los datos se realizó mediante la técnica de análisis de contenido, determinando las categorías a posteriori. Las experiencias de los estudiantes de pregrado fueron descritas en tres categorías: comparación entre el enfoque tradicional y el enfoque de promoción de experiencias significativas, experiencias de intervención en clases y reflexiones finales. Se concluye que para promover experiencias significativas a través de la natación es necesario incluir diversión, interacción social, desafío y aprendizaje personalmente relevante.

Study on the antidepressant activity of (2R,6R; 2S,6S)-Hydroxynorketamine (HNK) and its derivatives

Abstract Objective: This study mainly explores (2R,6R; 2S,6S)-HNK and its compounds whether there are antidepressant effects. Methods: Four HNK compounds were obtained from 2-(Chlorophenyl) Cyclopentylmethanone. Forced swimming test, locomotor sensitization test, and conditioned location preference test were used to screen the antidepressant activity of the synthesized target compounds. Results: In the case of 10 mg HNK treatment, compared with saline, the immobile time of mice in the HNK group, I5 group and I6 group at 1 h and 7 days had statistical significance. In the case of 10 mg HNK treatment, compared with saline, the immobile time of compound C and D groups in the glass cylinder area was significantly different. In the locomotor sensitization test, the movement distance of compound C and D groups on day 15 and day 7 mice increased significantly compared with the first day. In the conditioned place preference experiment, compound C and compound D induced conditioned place preference in mice compared with the Veh group. Conclusion: The results of the forced swimming test, locomotor sensitization test, and conditioned location preference test showed that compounds C and D may have certain anti-depressant activity. However, HNK exerts a rapid and significant antidepressant effect within 1 week, but the duration is short.

Metodología para el entrenamiento de las figuras en nadadoras artísticas categoría 11-12 años

El entrenamiento de las figuras en la natación artística constituye uno de los aspectos fundamentales en la preparación técnica de las nadadoras artísticas, su dominio es una condición para alcanzar el éxito deportivo. Sin embargo, en la actualidad son insuficientes los procedimientos y componentes que lo fundamentan. De ahí que la investigación está dirigida a comprobar el comportamiento de la aplicación de la metodología para el mejoramiento del entrenamiento de las figuras en las nadadoras artísticas. Con una población de ocho nadadoras artísticas de la categoría 11-12 años pertenecientes a la Escuela de Iniciación Deportiva Escolar "Capitán Orestes Acosta Herrera" de Santiago de Cuba. Se aplicó los métodos teóricos analítico-sintético y sistémico-estructural-funcional; con respecto a los empíricos el análisis documental y el diseño pre-experimental pretest-postest para un solo grupo y en los estadísticos la descriptiva con la media, moda y desviación típica; y la inferencial con la prueba de T Student para muestras relacionadas. En tal sentido, la propuesta se caracterizó por el empleo del enfoque sistémico a la reestructuración del contenido a partir de un plan de entrenamiento de las figuras. La calidad de la metodología quedó corroborada por los resultados obtenidos en la aplicación del pre-experimento confirmado por diferentes técnicas estadísticas que resaltan su funcionabilidad, sostenibilidad, pertinencia y factibilidad.

O treinamento de figuras no nado artístico é um dos aspectos fundamentais na preparação técnica dos nadadores artísticos, seu domínio é uma condição para alcançar o sucesso esportivo. No entanto, atualmente, os procedimentos e componentes nos quais ele se baseia são insuficientes. Por isso, a pesquisa tem como objetivo testar o comportamento da aplicação da metodologia para a melhoria do treinamento de figuras em nadadores artísticos. Com uma população de oito nadadores artísticos na categoria de 11-12 anos pertencentes à Escola de Iniciação Esportiva Escolar "Capitán Orestes Acosta Herrera", em Santiago de Cuba. Foram aplicados os métodos teóricos analítico-sintético e sistêmico-estrutural-funcional; com relação aos métodos empíricos, a análise documental e o desenho pré-experimental pré-teste-pós-teste para um único grupo e a estatística descritiva com a média, a moda e o desvio padrão; e a inferencial com o teste t de Student para amostras relacionadas. Nesse sentido, a proposta foi caracterizada pelo uso da abordagem sistêmica para a reestruturação do conteúdo com base em um plano de treinamento para as figuras. A qualidade da metodologia foi corroborada pelos resultados obtidos na aplicação do pré-experimento confirmados por diferentes técnicas estatísticas que destacam sua funcionalidade, sustentabilidade, relevância e viabilidade.

The training of the figures in artistic swimming constitutes one of the fundamental aspects in the technical preparation of artistic swimmers, its mastery is a condition to achieve sporting success. However, currently the procedures and components that support it are insufficient. Hence, the research is aimed at verifying the behavior of the application of the methodology for the improvement of the training of figures in artistic swimmers. With a population of eight artistic swimmers in the 11-12 years category belonging to the "Capitán Orestes Acosta Herrera" School of Sports Initiation in Santiago de Cuba. The analytical-synthetic and systemic-structural-functional theoretical methods were applied; with respect to the empirical ones, the documentary analysis and the pre-experimental pretest-postest design for a single group and in the statistical ones the descriptive one with the mean, mode and standard deviation; and the inferential with the T Student test for related samples. In this sense, the proposal was characterized by the use of the systemic approach to the restructuring of the content from a training plan of the figures. The quality of the methodology was corroborated by the results obtained in the application of the pre-experiment confirmed by different statistical techniques that highlight its functionality, sustainability, relevance and feasibility.

Efecto del Ejercicio en el Medio Acuático sobre la Aptitud Física en Personas con Discapacidad Intelectual: Una Revisión Sistemática / Effect of Exercise in Aquatic Environments on Physical Fitness in People with Intellectual Disabilities: A Systematic Review / Efeito do exercício aquático sobre a aptidão física em pessoas com deficiência intelectual: uma revisão sistemática

Resumen: Los programas de ejercicio en el medio acuático proporcionan un ambiente motivante y divertido, en el cual las personas con discapacidad intelectual pueden realizar actividades deportivas o recreativas de manera accesible, lo que incide positivamente en la condición física. Propósito: El objetivo de la revisión sistemática fue conocer los efectos del ejercicio acuático sobre la aptitud física en personas con discapacidad intelectual. Metodología: Para lograr el propósito del estudio, se llevó a cabo una búsqueda de literatura en las bases de datos Sport Discus, Science Direct, Scopus y PubMed, cuyas publicaciones comprenden del 2009 al 2018; como criterios de inclusión debían especificar el tipo de ejercicio, los componentes de la carga de entrenamiento, el tipo de discapacidad que presentaban los sujetos del estudio y que la duración de la intervención fue mayor a 4 semanas. Resultados: Solamente 5 trabajos cumplieron los criterios de selección. Aquellos en los que aplicaron intervenciones de natación y ejercicio combinado indicaron que se mejoraron elementos de la aptitud física importantes para la salud, así como el desenvolvimiento de actividades de la vida diaria. Se pudo concluir que se requieren investigaciones con mayor rigor metodológico, para clarificar el efecto del ejercicio en el medio acuático sobre los componentes de la aptitud física en personas con discapacidad intelectual.

Abstract: Exercise programs in aquatic environments guarantee a motivating and fun environment in which people with intellectual disabilities can carry out sports or recreational activities in an accessible way, which has a positive effect on their physical condition. Purpose: the objective of the systematic review was to know the effects of aquatic exercise on physical fitness in people with intellectual disabilities. Methodology: To achieve the purpose of the study, a literature search was conducted in the Sport Discus, Science Direct, Scopus, and PubMed databases, whose publications cover from 2009 to 2018. As selection criteria, these publications had to specify the type of exercise, the components of a load of training, the type of disability presented by the study subjects, and the duration of the intervention that should be greater than four weeks. Results: Only five studies met the selection criteria. the studies in which they applied swimming interruption and combined exercise showed that components of physical fitness important for health were improved, as well as the development of activities of daily living. It was concluded that studies with greater methodological rigor are required to clarify the effect of exercise in aquatic environments on the components of physical fitness in people with intellectual disabilities.

Resumo: Os programas de exercícios aquáticos proporcionam um ambiente motivador e divertido no qual pessoas com deficiências intelectuais podem praticar esportes ou atividades recreativas de maneira acessível, o que tem um impacto positivo sobre a condição física. Objetivo: O objetivo da revisão sistemática era descobrir os efeitos do exercício aquático sobre a aptidão física das pessoas com deficiência intelectual. Metodologia: Para atingir o objetivo do estudo, foi feita uma pesquisa bibliográfica nas bases de dados Sport Discus, Science Direct, Scopus e PubMed, cujas publicações foram de 2009 a 2018. Como critérios de seleção, essas publicações tinham que especificar o tipo de exercício, os componentes de uma carga de treinamento, o tipo de deficiência apresentada pelos sujeitos do estudo e a duração da intervenção que devia ser superior a quatro semanas. Resultados: Apenas cinco estudos cumpriram os critérios de seleção. Os estudos nos quais foram aplicados intervenções de natação e exercícios combinados indicaram que os componentes de aptidão física importantes para a saúde, assim como no desempenho das atividades da vida diária, foram melhorados. Concluiu-se que são necessários estudos com maior rigor metodológico para esclarecer o efeito do exercício aquático sobre os componentes da aptidão física das pessoas com deficiência intelectual.

Las figuras: su preparación en la natación artística escolar

Una de las tareas a resolver de forma inmediata en la natación artística escolar, se relaciona con la preparación técnica que constituye una parte fundamental en el proceso de entrenamiento de las nadadoras artísticas. En el presente artículo, se realizó una revisión bibliográfica que tuvo como objetivo abordar las principales consideraciones sobre el proceso de preparación técnica en la natación artística escolar, con particular énfasis en el entrenamiento de las figuras; además, se precisaron los aportes y las inconsistencias teóricas más relevantes que justifican el perfeccionamiento del proceso estudiado. Para lograrlo, se aplicaron como métodos científicos del nivel teórico, el analítico-sintético e inductivo-deductivo y como método empírico el análisis documental, con el fin de referenciar los resultados de investigaciones sobre esta temática desde una perspectiva analítica y crítica, lo que permitió establecer criterios de opinión y debate para lograr una comprensión del tema desarrollado; como conclusiones, se señaló que las limitaciones epistemológicas detectadas se resumen en insuficiencias metodológicas presentes en el contenido, los métodos, la dosificación y la distribución de las cargas por omisiones de procedimientos, ello dificultó la orientación acertada del entrenamiento de las figuras hacia el cumplimiento de los objetivos previstos.

SÍNTESE Uma das tarefas a ser resolvida imediatamente na natação artística escolar está relacionada à preparação técnica que constitui uma parte fundamental do processo de formação dos nadadores artísticos. Neste artigo, foi realizada uma revisão bibliográfica com o objetivo de abordar as principais considerações sobre o processo de preparação técnica na natação artística escolar, com ênfase especial no treinamento das figuras; além disso, foram especificadas as contribuições teóricas mais relevantes e as inconsistências que justificam o aperfeiçoamento do processo estudado. Para tanto, foram aplicados métodos científicos analítico-sintéticos e indutivo-dedutivos a nível teórico, e a análise documental foi utilizada como método empírico, com o objetivo de referenciar os resultados da pesquisa sobre este tema a partir de uma perspectiva analítica e crítica, o que permitiu estabelecer critérios de opinião e debate a fim de alcançar uma compreensão do tema desenvolvido; Como conclusões, foi apontado que as limitações epistemológicas detectadas estão resumidas em insuficiências metodológicas presentes no conteúdo, métodos, dosagem e distribuição das cargas devido a omissões de procedimentos, o que dificultou a orientação correta do treinamento dos números para o cumprimento dos objetivos previstos.

One of the tasks to be immediately solved in school artistic swimming, is related to the technical preparation that constitutes a fundamental part in the training process of artistic swimmers. In this article, it is offered the results of a bibliographical review that was carried out with the objective of address the main considerations about the process of technical preparation in school artistic swimming, with particular emphasis on the training of figures; in addition, the most relevant theoretical contributions and inconsistencies that justify the improvement of the studied process were specified. To achieve this, analytical-synthetic and inductive-deductive scientific methods were applied from the theoretical level, and documentary analysis as an empirical method, in order to reference the results of research on this subject from an analytical and critical perspective, which allowed establishing opinion and debate criteria to achieve an understanding of the topic developed; as conclusions, it was pointed out that the epistemological limitations detected are summarized in methodological insufficiencies present in the content, methods, dosage and distribution of the loads due to omissions of procedures, this made it difficult to correctly orient the training of the figures towards the fulfillment of the intended objectives.

The relationship between anthropometric variables and swimming efficiency in early pubescent female front crawl swimmers / Relación entre las variables antropométricas y la eficiencia de natación en nadadoras de estilo crol en la pubertad temprana

SUMMARY: The aim of this study was twofold. The first aim was to examine the association of anthropometric measures on kinematic characteristic which represent stroke efficiency in young female front crawl swimmers. The second aim was to create a prediction model which could provide help to swimming coaches with the purpose of easier and better selection of female front crawl swimmers by measuring and following basic morphological characteristics. Eighty female competitive swimmers all members of the swimming Clubs in province of Vojvodina, Serbia (age 12.52 ± 08 years, years of training involvement 4.05 ± 1.2 and personal best times over 50 m front crawl 32.79 ± 0.86 s) performed 50 m front crawl race. The 50 m front crawl swimming efficiency expressed through stroke index significantly was related to body height (r = 0.44, p = 0.000), body mass (r = 0.402, p = 0.000), sitting height (r = 0.612, p = 0.000) arm spam (r = 0.576, p = 0.000), biacromial diameter (r = 0.470, p = 0.000), bicrestal diameter (r = 0.348, p = 0.001) and with chest circumference (r = 0.427, p = 0.000). Regression equation for stroke index prediction was defined by following variables: body mass, sitting height, arm span, chest circumference with 43.5% explained variance. Additionally by analyzing obtained model the higher the values of SH, ARSP, CHICR and the lower values of BM in a group of early pubescent female swimmers the higher 50 m front crawl efficiency values will be.

Este estudio tiene dos objetivos principales. El primer objetivo fue examinar la asociación de las medidas antropométricas con las características cinemáticas que representan la eficiencia de la brazada en nadadoras jóvenes estilo crol. El segundo objetivo era crear un modelo de predicción que pudiera ayudar a los entrenadores de natación con el propósito de seleccionar mejor y más fácilmente a las nadadoras crol midiendo y siguiendo las características morfológicas básicas. Ochenta nadadoras competitivas, todas miembros de los clubes de natación en la provincia de Vojvodina, Serbia (edad 12,52 ± 8 años, años de participación en el entrenamiento 4,05 ± 1,2 y mejores tiempos personales en 50 m estilo crol 32,79 ± 0,86 s) realizaron una carrera de 50 m estilo crol. La eficiencia de nado crol de 50 m expresada a través del índice de brazada se relacionó significativamente con la altura del cuerpo (r = 0,44, p = 0,000), la masa corporal (r = 0,402, p = 0,000), la altura sentado (r = 0,612, p = 0,000) y el brazo. spam (r = 0,576, p = 0,000), diámetro biacromial (r = 0,470, p = 0,000), diámetro bicrestal (r = 0,348, p = 0,001) y con perímetro torácico (r = 0,427, p = 0,000). La ecuación de regresión para la predicción del índice de brazada se definió mediante las siguientes variables: masa corporal, altura sentada, extensión de los miembros superiores, circunferencia del pecho con una varianza explicada del 43,5 %. Además, al analizar el modelo obtenido, cuanto más altos sean los valores de SH, ARSP, CHICR y los valores más bajos de BM en un grupo de nadadoras púberes tempranas, mayores serán los valores de eficiencia de crol de 50 m.

Physical exercise suppresses hepatocellular carcinoma progression by alleviating hypoxia and attenuating cancer stemness through the Akt/GSK-3β/β-catenin pathway / 中西医结合学报

OBJECTIVE@#Physical exercise, a common non-drug intervention, is an important strategy in cancer treatment, including hepatocellular carcinoma (HCC). However, the mechanism remains largely unknown. Due to the importance of hypoxia and cancer stemness in the development of HCC, the present study investigated whether the anti-HCC effect of physical exercise is related to its suppression on hypoxia and cancer stemness.@*METHODS@#A physical exercise intervention of swimming (30 min/d, 5 d/week, for 4 weeks) was administered to BALB/c nude mice bearing subcutaneous human HCC tumor. The anti-HCC effect of swimming was assessed in vivo by tumor weight monitoring, hematoxylin and eosin (HE) staining, and immunohistochemistry (IHC) detection of proliferating cell nuclear antigen (PCNA) and Ki67. The expression of stemness transcription factors, including Nanog homeobox (NANOG), octamer-binding transcription factor 4 (OCT-4), v-Myc avian myelocytomatosis viral oncogene homolog (C-MYC) and hypoxia-inducible factor-1α (HIF-1α), was detected using real-time reverse transcription polymerase chain reaction. A hypoxia probe was used to explore the intratumoral hypoxia status. Western blot was used to detect the expression of HIF-1α and proteins related to protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β)/β-catenin signaling pathway. The IHC analysis of platelet endothelial cell adhesion molecule-1 (CD31), and the immunofluorescence co-location of CD31 and desmin were used to analyze tumor blood perfusion. SMMC-7721 cells were treated with nude mice serum. The inhibition effect on cancer stemness in vitro was detected using suspension sphere experiments and the expression of stemness transcription factors. The hypoxia status was inferred by measuring the protein and mRNA levels of HIF-1α. Further, the expression of proteins related to Akt/GSK-3β/β-catenin signaling pathway was detected.@*RESULTS@#Swimming significantly reduced the body weight and tumor weight in nude mice bearing HCC tumor. HE staining and IHC results showed a lower necrotic area ratio as well as fewer PCNA or Ki67 positive cells in mice receiving the swimming intervention. Swimming potently alleviated the intratumoral hypoxia, attenuated the cancer stemness, and inhibited the Akt/GSK-3β/β-catenin signaling pathway. Additionally, the desmin+/CD31+ ratio, rather than the number of CD31+ vessels, was significantly increased in swimming-treated mice. In vitro experiments showed that treating cells with the serum from the swimming intervention mice significantly reduced the formation of SMMC-7721 cell suspension sphere, as well as the mRNA expression level of stemness transcription factors. Consistent with the in vivo results, HIF-1α and Akt/GSK-3β/β-catenin signaling pathway were also inhibited in cells treated with serum from swimming group.@*CONCLUSION@#Swimming alleviated hypoxia and attenuated cancer stemness in HCC, through suppression of the Akt/GSK-3β/β-catenin signaling pathway. The alleviation of intratumoral hypoxia was related to the increase in blood perfusion in the tumor. Please cite this article as: Xiao CL, Zhong ZP, Lü C, Guo BJ, Chen JJ, Zhao T, Yin ZF, Li B. Physical exercise suppresses hepatocellular carcinoma progression by alleviating hypoxia and attenuating cancer stemness through the Akt/GSK-3β/β-catenin pathway. J Integr Med. 2023; 21(2): 184-193.

T 2-mapping and BOLD to evaluate the effect of swimming rehabilitation exercise on paraspinal muscles in rats model with discogenic low back pain / 中华放射学杂志

Objective:To explore MRI T 2-mapping and blood oxygenation level dependent (BOLD) to evaluate the functional changes of paraspinal muscle in rats with discogenic low back pain (DLBP) after swimming. Methods:Totally 54 female 1-month-old SD rats were selected, which were divided into 3 groups by random number table method, sham operation (Sham) group, DLBP non-swimming group and DLBP swimming group, with 18 rats in each group. Under the guidance of X-ray fluoroscopy, the L4/5 and L5/6 intervertebral discs of the rats in the DLBP non-swimming group and DLBP swimming group were punctured by the posterior approach, and establishment of DLBP rat model by destroying nucleus pulposus, and only paraspinal muscles at the same level were punctured in the Sham group. After modeling, the DLBP swimming group received swimming exercise intervention for 5 consecutive days (30 min/d), while the DLBP non-swimming group and Sham group did not receive any rehabilitation exercise intervention. Each group was divided into 3 time point subgroups on average, the T 2-mapping and BOLD sequences were scanned at 30, 90 and 180 days after modeling to obtain the T 2 value, R 2* value of the paraspinal muscles, and the paraspinal muscles at the modeling level were taken for immunofluorescence staining, and the fluorescence intensity of myosin heavy chain (MYH)1 (type Ⅱ muscle fiber) and MYH7 (type I muscle fiber) was analyzed. One-way analysis of variance was used for comparison among the 3 groups, and the Bonferroni method was used for multiple comparisons, and Pearson correlation coefficient was used to evaluate the correlation between quantitative MRI parameters T 2 value, R 2* value and MYH1, MYH7 immunofluorescence intensity of rat paraspinal muscles at 180 days after modeling. Results:At 30 days after modeling, there was no significant difference in T 2 value and R 2* value among the 3 groups (all P>0.05). At 90 days after modeling, the T 2 value of the DLBP swimming group was higher than that of the DLBP non-swimming group, and the T 2 value of the DLBP non-swimming group was lower than that of the Sham group (all P<0.05), and there was no significant difference in the R 2* value among the 3 groups ( P>0.05). At 180 days after modeling, the T 2 value of the DLBP swimming group was higher than that of the DLBP non-swimming group, and the R 2* value was lower than that of the DLBP non-swimming group; the T 2 value of the DLBP non-swimming group was lower than that of the Sham group, and the R 2* value was higher than that of the Sham group (all P<0.05). At 30 and 90 days after modeling, there was no significant difference in the expressions of MYH1 and MYH7 among the 3 groups (all P>0.05). At 180 days after modeling, the expression of MYH1 decreased and the expression of MYH7 increased in the DLBP swimming group compared with the DLBP non-swimming group; the expression of MYH1 increased and the expression of MYH7 decreased in the DLBP non-swimming group compared with the Sham group (all P<0.05). At 180 days after modeling, the T 2 value had a moderate negative correlation with the fluorescence intensity of MYH1 ( r=-0.511, P=0.043), and a moderate positive correlation with the fluorescence intensity of MYH7 ( r=0.564, P=0.023); R 2* value was moderate positive correlated with the fluorescence intensity of MYH1 ( r=0.625, P=0.010), and moderate negative correlated with the fluorescence intensity of MYH7 ( r=-0.653, P=0.006). Conclusions:Swimming exercise can improve the reduction of water content and perfusion in the paraspinal muscles of DLBP rats, and reduce the transformation of muscle fibers from type Ⅰ to type Ⅱ, the changes of T 2 and R 2* value can reflect the transformation of paraspinal muscle fiber types to a certain extent.

Bladder microenvironment actuated proteomotors with ammonia amplification for enhanced cancer treatment

Enzyme-driven micro/nanomotors consuming in situ chemical fuels have attracted lots of attention for biomedical applications. However, motor systems composed by organism-derived organics that maximize the therapeutic efficacy of enzymatic products remain challenging. Herein, swimming proteomotors based on biocompatible urease and human serum albumin are constructed for enhanced antitumor therapy via active motion and ammonia amplification. By decomposing urea into carbon dioxide and ammonia, the designed proteomotors are endowed with self-propulsive capability, which leads to improved internalization and enhanced penetration in vitro. As a glutamine synthetase inhibitor, the loaded l-methionine sulfoximine further prevents the conversion of toxic ammonia into non-toxic glutamine in both tumor and stromal cells, resulting in local ammonia amplification. After intravesical instillation, the proteomotors achieve longer bladder retention and thus significantly inhibit the growth of orthotopic bladder tumor in vivo without adverse effects. We envision that the as-developed swimming proteomotors with amplification of the product toxicity may be a potential platform for active cancer treatment.

Changes in body composition of Wistar rats: effects of high-intensity interval training

The present study aimed to investigate the effectiveness of high-intensity interval training (HIIT) in the body composition of Wistar rats. The HIIT protocol consisted of high-intensity swimming three times a week for four weeks. There were no differences between groups as to the Lee index. However, the weights of the perigonadal (p=0.001) and retroperitoneal (p=0.026) fats were significantly different between the Control Group (CG, n=10) vs. Trained Group (TG, n=10), respectively. There was also a significant increase in the body weight of the animals in TG (16.43%) and CG (7.19%) at the end of the experiment. These findings suggested that HIIT was not sufficient to improve significantly the body composition of rats.

Efeito da padronização dos critérios de observação e de avaliação da técnica da braça do nado crawl na confiabilidade inter e intra avaliadores / Effect of standardizing observation and rating criteria for the front crawl stroke technique on inter- and intra-rater reliability

RESUMO Esse estudo teve por objetivo avaliar o efeito da padronização dos critérios de observação e de avaliação da técnica da braçada do nado crawl na confiabilidade inter e intra avaliadores para uma proposta de lista de observação. Dois professores e dois treinadores de natação competitiva com formação acadêmica diferentes foram responsáveis por avaliar a técnica da braçada do nado crawl de 44 nadadores por meio de vídeo. Cada nadador realizou um percurso de 25m em velocidade confortável tendo seu deslocamento gravado nos planos lateral e frontal, ambos submersos e fora d'água, nos 10 m finais da piscina. No percurso de filmagem os nadadores não realizaram a respiração lateral. Somente o movimento realizado pelo braço direito foi foco de observação dos avaliadores e com base em uma lista de verificação. Após as filmagens os avaliadores participaram de três etapas: na primeira etapa houve uma intervenção para padronização dos critérios de observação e de avaliação. Na segunda etapa testou-se a concordância inter-avaliadores e, na terceira, a concordância intra-avaliador. Na segunda etapa do estudo a concordância variou de pequeno a baixa (k=0,08 e k=0,38). Na terceira etapa alguns avaliadores apresentaram concordância pobre e baixa (k=-0,13 e k=0,35), enquanto outros apresentaram concordância entre razoável e praticamente perfeita (k=0,64 e k=0,87). A partir dos resultados apresentados concluiu-se que a proposta de intervenção não surtiu o efeito desejado de padronização dos critérios de observação e avaliação entre os avaliadores.

ABSTRACT This study aimed to assess the effect of standardizing observation and rating criteria for the front crawl stroke technique on inter- and intra-rater reliability in order to propose an observation list. Two teachers and two competitive swimming coaches with different academic backgrounds were responsible for evaluating the front crawl stroke technique of 44 swimmers using video. Each swimmer completed a 25m course at a comfortable speed, having their displacement recorded in the lateral and frontal planes, both submerged and out of water, in the final 10 m of the pool. Throughout the recording, the swimmers did not breath laterally. Only the movement performed by the right arm was the raters' focus of observation and was based on a checklist. After the shooting, the raters participated in three stages: in the first stage, there was an intervention to standardize the observation and rating criteria; inter-rater agreement was tested in the second stage, while intra-rater agreement was obtained in the third. In the second stage of the study, the agreement ranged from small to low (k=0.08 and k=0.38). In the third stage, some raters showed poor and low agreement (k=-0.13 and k=0.35), while others showed agreement between reasonable and virtually perfect (k=0.64 and k=0.87). From the results presented, it was concluded that the intervention proposal did not have the desired effect of standardizing the observation and rating criteria among the raters.

Influence of swimming training on fitness indicators in children / Influência do treinamento de natação sobre os indicadores de aptidão física em crianças / Influencia del entrenamiento de natación en los indicadores de aptitud física de los niños

ABSTRACT Introduction The specialized technical teaching and swimming training methods for children are the basis for improving the effect of swimming training and reducing the occurrence of sports injuries. In recent years, swimming physical training technology in China has developed rapidly. Swimming physical training for children can improve the comprehensive sports quality of young people. Objective In this paper, the indexes of 50m butterfly and 50m breaststroke were determined. These data quantitatively examine the effect of the program on swimming performance. Methods 18 children and adolescent swimmers participated in the sample analyzed in this study. In this paper, 18 participants were divided into experimental and control groups. These groups have four swimming styles: butterfly, breaststroke, backstroke, and freestyle. Results After two months of coordination exercises, the performance of butterfly and frog swimming was partially improved. There were significant differences in the data (P<0.05). Conclusion The fitness training process can improve the overall quality of athletes. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução O ensino técnico especializado e os métodos de treinamento em natação para crianças são a base para melhorar o efeito do treinamento de natação e reduzir a ocorrência de lesões esportivas. Nos últimos anos, a tecnologia de treinamento físico em natação na China se desenvolveu rapidamente. O treinamento físico da natação para crianças pode melhorar a qualidade esportiva integral dos jovens. Objetivo Neste artigo, foram determinados os índices de 50m de borboleta e 50m de peito. Estes dados examinam quantitativamente o efeito do programa sobre o desempenho da natação. Métodos Um total de 18 crianças e adolescentes nadadores participaram da amostra analisada neste estudo. Neste trabalho, 18 participantes foram divididos em grupos experimentais e de controle. Estes grupos têm quatro estilos de natação: borboleta, nado de peito, nado de costas e estilo livre. Resultados Após dois meses de exercícios de coordenação, o desempenho do nado borboleta e do nado sapo foi parcialmente melhorado. Houve diferenças significativas nos dados (P<0,05). Conclusão O processo de treinamento de aptidão física pode melhorar a qualidade global dos atletas. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción La enseñanza técnica especializada y los métodos de entrenamiento en natación para niños son la base para mejorar el efecto del entrenamiento de natación y reducir la aparición de lesiones deportivas. En los últimos años, la tecnología del entrenamiento físico de la natación en China se ha desarrollado rápidamente. El entrenamiento físico de natación para niños puede mejorar la calidad deportiva integral de los jóvenes. Objetivo En este trabajo se determinaron los índices de 50 metros mariposa y 50 metros braza. Estos datos examinan cuantitativamente el efecto del programa en el rendimiento de la natación. Métodos Un total de 18 niños y adolescentes nadadores participaron en la muestra analizada en este estudio. En este trabajo, 18 participantes fueron divididos en grupos experimentales y de control. Estos grupos tienen cuatro estilos de natación: mariposa, braza, espalda y estilo libre. Resultados Tras dos meses de ejercicios de coordinación, el rendimiento de la natación en mariposa y rana mejoró parcialmente. Hubo diferencias significativas en los datos (P<0,05). Conclusión El proceso de entrenamiento físico puede mejorar la calidad general de los deportistas. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Potential physical endurance training system for swimmers / Potencial sistema de treinamento de resistência física para nadadores / Potencial sistema de entrenamiento de resistencia física para nadadores

ABSTRACT Introduction: Endurance and speed are fundamental to swimming. It is also essential for athletes to use the correct practice method during training to improve swimmers' level of strength, endurance, and speed. Standardized swimming exercises can also reduce the inability of conventional land sports to adapt to the transition process from land to water. At the same time, standardized swimming exercises can also reduce the inability of conventional land sports to adapt to the transition process from land to water. This total swimming ability is also the goal pursued by many coaches and players. Objective: This study analyzes the training methods to improve swimmers' strength, endurance, and speed. The results of this work can establish a theoretical basis for coaches to formulate training plans. Methods: This paper selects 20 swimmers as the object of research. There were ten males and ten females. All athletes participate in an endurance training program. This paper records the training intensity and endurance data during the athlete's training. This paper uses mathematical statistics for data analysis. Results: The athletes' human body's technical level improved significantly after the endurance system exercise. The data were statistically significant (P<0.05). Conclusion: Endurance training can improve swimmers' lower body strength. This training can make special training infinitely close to the demands of competition. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: Resistência e velocidade são fundamentais na prática da natação. Também é essencial que os atletas utilizem o método de prática correto durante o treinamento para melhorar o nível de força, resistência e velocidade dos nadadores. Os exercícios de natação padronizados também podem reduzir a incapacidade dos esportes terrestres convencionais de se adaptar ao processo de transição da terra para a água. Esta capacidade plena de natação é também o objetivo perseguido por muitos treinadores e jogadores. Objetivo: Este estudo tem como objetivo analisar os métodos de treinamento para melhorar a força, resistência e velocidade dos nadadores. Métodos: 20 nadadores voluntários foram selecionados como o objeto de pesquisa. Todos os atletas participam de um programa de treinamento de resistência. Este artigo registra a intensidade do treinamento e os dados de resistência durante o treinamento do atleta. Este artigo usa estatísticas matemáticas para análise de dados. Resultados: O nível técnico da função do corpo humano dos atletas melhorou significativamente após o exercício do sistema de endurance. Os dados foram estatisticamente significativos (P<0,05). Conclusão: O treinamento de resistência pode melhorar a força dos membros inferiores dos nadadores. Este treinamento pode fazer com que o treinamento dedicado alcance as exigências da competição. Os resultados apresentados podem estabelecer uma base teórica para que os treinadores formulem planos de treinamento. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: La resistencia y la velocidad son fundamentales en la práctica de la natación. También es esencial que los deportistas utilicen el método de práctica correcto durante el entrenamiento para mejorar el nivel de fuerza, resistencia y velocidad de los nadadores. Los ejercicios de natación estandarizados también pueden reducir la incapacidad de los deportes terrestres convencionales para adaptarse al proceso de transición de la tierra al agua. Al mismo tiempo, los ejercicios de natación estandarizados también pueden reducir la incapacidad de los deportes terrestres convencionales para adaptarse al proceso de transición de la tierra al agua. Esta capacidad total de nadar es también el objetivo que persiguen muchos entrenadores y jugadores. Objetivo: Este estudio pretende analizar los métodos de entrenamiento para mejorar la fuerza, la resistencia y la velocidad de los nadadores. Los resultados de este trabajo pueden establecer una base teórica para que los entrenadores formulen planes de entrenamiento. Métodos: Este trabajo selecciona 20 nadadores como objeto de investigación. Había diez hombres y diez mujeres. Todos los atletas participan en un programa de entrenamiento de resistencia. Este documento registra la intensidad del entrenamiento y los datos de resistencia durante el entrenamiento del atleta. Este documento utiliza la estadística matemática para el análisis de los datos. Resultados: El nivel técnico de la función del cuerpo humano de los atletas mejoró significativamente después del ejercicio del sistema de resistencia. Los datos fueron estadísticamente significativos (P<0,05). Conclusión: El entrenamiento de resistencia puede mejorar la fuerza de la parte inferior del cuerpo de los nadadores. Los resultados presentados pueden establecer una base teórica para que los formadores formulen planes de entrenamiento. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Influence of high-intensity exercise on physical fitness of swimmers / Influência do exercício de alta intensidade sobre a aptidão física dos nadadores / Influencia del ejercicio de alta intensidad en la aptitud física de los nadadores

ABSTRACT Introduction High-intensity swimming requires athletes to have explosive power, endurance, lactic acid resistance, aerobic metabolism, and other qualities. Pre-competition physical training is mainly based on high interval training, promoting ATP-CP synthesis in the body. It can enhance the resistance to lactic acid and promote lactic acid clearance. Objective This article explores the effect of high-intensity pre-competition training on the physical fitness of swimmers. The results can be used as a reference for swimmers to perform high-intensity training before the competition. Methods Eight swimmers were selected by random sampling. The study subjects received eight weeks of high-intensity training before the competition. The athletes' gas metabolism and anaerobic thresholds were detected before and after training. At the same time, the physiological and chemical indicators of the experimental subjects were detected in this paper. Finally, this paper analyzes the experimental results by employing mathematical statistics. Results The metabolism function of the athletes changed significantly in the later period of pre-competition training (P<0.05). Serum lactate concentration had no significant effect on the anaerobic threshold (P>0.05). Conclusion High-intensity exercise has a particular promotion effect on improving the physical quality of swimmers. This exercise can lay a solid foundation for the swimmer's physical fitness. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMO Introdução A natação de alta intensidade requer que os atletas tenham uma força explosiva, resistência, tolerância ao ácido láctico, metabolismo aeróbico e outras qualidades. O treinamento físico pré-competição é baseado principalmente no treinamento de alto intervalo, o que pode promover a síntese de ATP-CP no corpo. Ele pode aumentar a resistência ao ácido láctico e promover a sua eliminação. Objetivo Este artigo explora o efeito do treinamento pré-competição de alta intensidade sobre a aptidão física dos nadadores. Os resultados podem ser usados como referência para os nadadores realizarem treinamentos de alta intensidade antes da competição. Métodos Oito nadadores foram selecionados por amostragem aleatória. Os sujeitos do estudo receberam oito semanas de treinamento de alta intensidade antes da competição. O metabolismo dos gases e os limiares anaeróbicos dos atletas foram detectados antes e depois do treinamento. Paralelamente, os indicadores fisiológicos e químicos dos sujeitos experimentais foram detectados neste trabalho. Finalmente, este trabalho analisa os resultados experimentais empregando estatísticas matemáticas. Resultados A função metabólica dos atletas alterou-se significativamente no último período de treinamento pré-competição (P<0,05). A concentração sérica de lactato não teve efeito significativo no limiar anaeróbico (P>0,05). Conclusão O exercício de alta intensidade tem um efeito especial de promoção na melhoria da qualidade física dos nadadores. Este exercício pode estabelecer uma base sólida para a aptidão física do nadador. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción La natación de alta intensidad requiere que los atletas tengan fuerza explosiva, resistencia, tolerancia al ácido láctico, metabolismo aeróbico y otras cualidades. El entrenamiento físico previo a la competición se basa principalmente en el entrenamiento de alto intervalo, que puede promover la síntesis de ATP-CP en el cuerpo. Puede aumentar la resistencia al ácido láctico y favorecer su eliminación. Objetivo Este trabajo explora el efecto del entrenamiento de alta intensidad previo a la competición en la condición física de los nadadores. Los resultados pueden servir de referencia para que los nadadores realicen un entrenamiento de alta intensidad antes de la competición. Métodos Se seleccionaron ocho nadadores por muestreo aleatorio. Los sujetos del estudio recibieron ocho semanas de entrenamiento de alta intensidad antes de la competición. Se detectó el metabolismo gaseoso y los umbrales anaeróbicos de los atletas antes y después del entrenamiento. Paralelamente, en este trabajo se detectaron los indicadores fisiológicos y químicos de los sujetos experimentales. Por último, este documento analiza los resultados experimentales empleando estadísticas matemáticas. Resultados La función metabólica de los atletas cambió significativamente en el último período de entrenamiento previo a la competición (P<0,05). La concentración de lactato sérico no tuvo un efecto significativo sobre el umbral anaeróbico (P>0,05). Conclusión El ejercicio de alta intensidad tiene un efecto promotor especial en la mejora de la calidad física de los nadadores. Este ejercicio puede establecer una base sólida para la aptitud física del nadador. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Relative age in Brazilian swimmers and para swimmers / Idade relativa em nadadores e paranadadores brasileiros

abstract This study aimed to analyze the relationships between swimming competitive events, functional classification and relative age and to detect if the relative age affects performance in Brazilian swimmers and para swimmers. Data were retrieved from public databases and birth dates were classified in four quartiles (Q1 = January-March; Q2 = April-June; Q3 = July-September; Q4 = October-December). Descriptive statistics, Chi-square tests and ANOVA were used. The 50 m freestyle is the competitive event with 2349 swimmers, followed by 100 m (n = 1817) and 200 m freestyle (n = 905), and 200 m butterfly with 42 swimmers. Para swimmers are mainly distributed to S14, S6 and S5 functional classes (n = 140, 87 and 45), and individual medley events were less represented at SM3, SM9 and SM11 (n = 1 swimmer). Most of swimming events (86.36%) and para swimming functional classes (51.43%) are represented by swimmers and para swimmers born in the first and second quartiles. Moderate associations between functional classification and relative age were observed (p < 0.0001, Cramer's V = 0.277). No effects of relative age on swimmers and para swimmers' performance were noticed (p > 0.05). The great functional class seems to be related to great para swimmers' relative age. Quartiles distribution shows the advantage of being born in the first months of the year to be registered among the most talented Brazilian swimmers and para swimmers.

resumo Este estudo teve como objetivo analisar as relações entre eventos competitivos de natação, classificação funcional e idade relativa e detectar se a idade relativa afeta o desempenho em nadadores e paranadadores brasileiros. Os dados foram recuperados de bancos de dados públicos e as datas de nascimento foram classificadas em quatro quartis (Q1 = janeiro-março; Q2 = abril-junho; Q3 = julho-setembro; Q4 = outubro-dezembro). Utilizou-se estatística descritiva, teste Qui-quadrado e ANOVA. Os 50 m livre é a prova competitiva com 2.349 nadadores, seguido de 100 m (n = 1.817) e 200 m livre (n = 905), e 200 m borboleta com 42 nadadores. Os paranadadores estão distribuídos principalmente nas classes funcionais S14, S6 e S5 (n = 140, 87 e 45), e as provas individuais de medley foram menos representadas em SM3, SM9 e SM11 (n = 1 nadador). A maioria das provas de natação (86,36%) e classes funcionais de paranatação (51,43%) são representadas por nadadores e paranadadores nascidos no primeiro e segundo quartis. Associações moderadas entre classificação funcional e idade relativa foram observadas (p < 0,0001, V de Cramer = 0,277). Não foram observados efeitos da idade relativa no desempenho de nadadores e paranadadores (p > 0,05). A grande classe funcional parece estar relacionada com a idade relativa dos grandes paranadadores. A distribuição por quartis mostra a vantagem de ter nascido nos primeiros meses do ano para ser registrado entre os mais talentosos nadadores e paranadadores brasileiros.

Interval training effects on cardiorespiratory capacity of swimmers / Efeito do treinamento intervalado sobre a capacidade cardiorrespiratória de nadadores / Efecto del entrenamiento por intervalos en la capacidad cardiorrespiratoria de nadadores

ABSTRACT Introduction: Cardiopulmonary function is directly related to the body's ability to perform metabolism under aerobic conditions. It is a key characteristic for the training of professional swimmers. It is believed that adding interval training to traditional workouts may contribute to the aerobic endurance of these athletes. Objective: Evaluate the interval training effects on the cardiorespiratory capacity of swimmers. Methods: Twenty volunteer swimmers were randomly divided into two groups for seven weeks. There were 4 hours of class per week, totaling 28 hours of training. In the formal training stage, the experimental group performed intermediate-intensity training, while the control group continued to perform traditional swim team training. The experimental indicators pertinent to the evaluated athletes were collected, tested, and analyzed before and after the experiment. Results: The VO2 of the athletes in the experimental group increased from 3.90±0.67L/min before the experiment to 4.06±0.73L/min after the experiment; VE increased from 156.08±35.76L before the experiment to 180.08±39.42L after the experiment; underwater endurance time increased from 46.80±8.43s before the experiment to 55.49±7.60s after the experiment. Conclusion: Intermittent training improves athletes' physical fitness and sports capacity, being an effective method to improve cardiopulmonary function. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: A função cardiopulmonar está diretamente relacionada à capacidade do organismo de executar a metabolização sob condições aeróbicas. É uma característica chave para os treinamentos de nadadores profissionais e acredita-se que a adição do treinamento intervalado nos treinos tradicionais possa contribuir à resistência aeróbica desses atletas. Objetivo: Avaliar o efeito do treinamento intervalado sobre a capacidade cardiorrespiratória dos nadadores. Métodos: Vinte nadadores voluntários foram divididos aleatoriamente em dois grupos durante 7 semanas. Foram 4 horas de aula por semana, totalizando 28 horas de treino. Na etapa de treinamento formal, o grupo experimental realizou essencialmente o treinamento de intensidade intermediária, enquanto o grupo de controle permaneceu executando o treinamento tradicional da equipe de natação. Os indicadores experimentais pertinentes aos atletas avaliados foram coletados, testados e analisados antes e depois do experimento. Resultados: O VO2 dos atletas do grupo experimental aumentou de 3,90±0,67L/min antes do experimento para 4,06±0,73L/min após o experimento; o VE aumentou de 156,08±35,76L antes do experimento para 180,08±39,42L após o experimento; o tempo de resistência subaquática aumentou de 46,80±8,43s antes do experimento para 55,49±7,60s após o experimento. Conclusão: O treinamento intermitente contribui para melhorar a aptidão física e a capacidade esportiva dos atletas, sendo um método eficaz no aprimoramento da função cardiopulmonar. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: La función cardiopulmonar está directamente relacionada con la capacidad del organismo para realizar el metabolismo en condiciones aeróbicas. Es una característica clave para los entrenamientos de los nadadores profesionales y se cree que la adición del entrenamiento interválico en los entrenamientos tradicionales puede contribuir a la resistencia aeróbica de estos atletas. Objetivo: Evaluar el efecto del entrenamiento por intervalos sobre la capacidad cardiorrespiratoria de los nadadores. Métodos: Veinte nadadores voluntarios fueron divididos aleatoriamente en dos grupos durante 7 semanas. Se impartieron 4 horas de clase a la semana, totalizando 28 horas de entrenamiento. En la etapa de entrenamiento formal, el grupo experimental realizó esencialmente un entrenamiento de intensidad intermedia, mientras que el grupo control permaneció realizando el entrenamiento tradicional del equipo de natación. Los indicadores experimentales pertinentes a los atletas evaluados fueron recogidos, testados y analizados antes y después del experimento. Resultados: El VO2 de los atletas del grupo experimental aumentó de 3,90±0,67L/min antes del experimento a 4,06±0,73L/min después del experimento; el VE aumentó de 156,08±35,76L antes del experimento a 180,08±39,42L después del experimento; el tiempo de resistencia subacuática aumentó de 46,80±8,43s antes del experimento a 55,49±7,60s después del experimento. Conclusión: El entrenamiento por intervalos contribuye a mejorar la forma física y la capacidad deportiva de los atletas, siendo un método eficaz para mejorar la función cardiopulmonar. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Lilian Harrison y la travesía del Río de la Plata (1923): repercusión en la prensa uruguaya / Lilian Harrison e a travessia do Rio da Prata (1923): repercussão na imprensa uruguaia / Lilian Harrison and the crossing of the River Plate (1923): repercussion in the Uruguayan press

RESUMEN Lilian Harrison fue la primera persona en completar la travesía del Río de la Plata a nado, entre Colonia (Uruguay) y Punta Lara (Argentina) en 1923. La prensa argentina de la época coronó la victoria como un logro de toda la nación, a despecho de las apelaciones sexistas de los reportajes. Este artículo pretende analizar los discursos de la prensa uruguaya sobre la hazaña de la nadadora, utilizando las principales publicaciones periódicas de la época. El análisis de los reportajes permite concluir que, además de los artículos sexistas, que disminuían los logros de la atleta en comparación con sus compañeros masculinos, había cierto nivel de contrariedad en los reportajes, lo que indicaba el desagrado de la prensa hacia los propios nadadores del país.

ABSTRACT Lilian Harrison was the first person to complete the crossing of the River Plate by swimming between Colonia (Uruguay) and Punta Lara (Argentina) in 1923. The Argentine press of the time crowned the victory as an achievement of the whole nation, despite the sexist appeals of the reports. This article aims to analyse the discourses of the Uruguayan press about the swimmer's achievement, using the main periodicals published at the time. An analysis of the reports allows us to conclude that, in addition to the sexist articles, which also diminished the athlete's achievements compared to her male companions, there was some level of contrariness in the reports, signalling the displeasure of the press towards the country's swimmers.

RESUMO Lilian Harrison foi a primeira pessoa a completar a Travessia do Rio da Prata à nado, entre Colônia (Uruguay) e Punta Lara (Argentina) no ano de 1923. A imprensa argentina da época coroou a vitória como uma conquista de toda a nação, em que pesem os apelos sexistas das reportagens. Esse artigo tem como objetivo analisar os discursos da imprensa Uruguaya sobre o feito da nadadora, utilizando os principais periódicos publicados na época. Uma análise das reportagens permite concluir que, para além das matérias sexistas, que também diminuíram os feitos da atleta frente aos companheiros do gênero masculino, houve algum nível de contrariedade nas reportagens, sinalizando o desagrado da imprensa em relação aos próprios nadadores do país.