ABSTRACT
In this study, a surface electromyography (sEMG) and blood oxygen signal real-time monitoring system is designed to explore the changes of physiological signals during muscle fatigue, so as to detect muscle fatigue. The analysis method of sEMG and the principle of blood oxygen detection are respectively introduced, and the system scheme is expounded. The hardware part of the system takes STM32 as the core. Conditioning module composition; blood oxygen signal acquisition is based on near infrared spectroscopy (NIRS), specifically including light source, light source driving, photoelectric conversion, signal conditioning and other modules. The system software part is based on the real-time uC/OS-III software system. The characteristic parameters of sEMG were extracted by isometric contraction local muscle fatigue experiment; the relative changes of oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) were calculated in the forearm blocking experiment, thereby verifying that the system collects two signals effectiveness.
Subject(s)
Muscle, Skeletal , Oxygen , Electromyography , Muscle Fatigue/physiology , ComputersABSTRACT
Based on the joint analysis of EMG spectrum and amplitude method (JASA), a study on muscle fatigue assessment of spinal surgical instruments based on surface EMG signals was carried out, and a comparative evaluation of the operating comfort before and after the optimization of spinal surgical instruments was completed. A total of 17 subjects were recruited to collect the surface EMG signals of their brachioradialis and biceps. Five surgical instruments before and after optimization were selected for data comparison, and the operating fatigue time proportion of each group of instruments under the same task was calculated based on the RMS and MF eigenvalues. The results showed that when completing the same operation task, the operation fatigue time of the surgical instruments before optimization was significantly higher than that after optimization (P<0.05); there was no significant difference in the fatigue status of brachioradialis and biceps when operating the same instrument (P>0.05). These results provide objective data and reference for the ergonomic design of surgical instruments and fatigue damage protection.
Subject(s)
Humans , Muscle Fatigue/physiology , Muscle, Skeletal , Electromyography , ErgonomicsABSTRACT
ABSTRACT Introduction: Skiing is a sport that demands the high performance of motor coordination with high energy consumption, factors that strongly influence muscle fatigue. Athletes who experience this phenomenon tend to present a decline in performance, generating psychological irritability and impairment in concentration. Diet is closely related to athletic performance, but the proper prescription for skiing athletes still lacks studies. Objective: To explore the methods of recovery from sports fatigue in skiers by providing up-to-date perspectives for effective nutritional intervention during the recovery stage. Methods: Seven young male skiers were selected as research subjects, and caloric intake, among other conditions, was recorded in detail. After three weeks, indices of body weight, body fat rate, serum metabolism, cardiopulmonary capacity, and energy metabolism, among other relevant information, were duly recorded and compared. Results: The intervention did not significantly impact lean body mass indices (p>0.05). The athletes' body weight decreased significantly, and the body fat rate decreased significantly after the nutritional intervention; The analyzed biomarkers were positively impacted, except the urea nitrogen concentration that showed a tendency to increase after the nutritional intervention, an effect that may be linked to the proportional increase of protein intake. Conclusion: The proposed nutritional intervention positively impacted the skiers' energy metabolism, directly impacting the athletes' recovery from sports fatigue. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.
RESUMO Introdução: O esqui é um esporte que exige alto desempenho de coordenação motora com um elevado consumo de energia, fatores que influenciam fortemente a fadiga muscular. Atletas que experienciam esse fenômeno, tendem a apresentar um declínio no nível do desempenho, gerando irritabilidade psicológica e prejuízos na concentração. A dieta está intimamente relacionada ao desempenho atlético, porém a receita adequada para os atletas em esqui ainda carece de estudos. Objetivo: Explorar os métodos de recuperação da fadiga esportiva nos esquiadores fornecendo perspectivas atualizadas para uma intervenção nutricional eficaz durante a etapa de recuperação. Métodos: Sete jovens esquiadores do sexo masculino foram selecionados como sujeitos da pesquisa, e a ingestão calórica, entre outras condições foram detalhadamente registradas. Após três semanas, índices de peso corporal, taxa de gordura corporal, metabolismo sérico, capacidade cardiopulmonar, metabolismo energético, entre outras informações relevantes foram devidamente registradas e comparadas. Resultados: A intervenção não impactou significativamente nos índices de massa magra corporal (p>0,05). O peso corporal dos atletas diminuiu significativamente e a taxa de gordura corporal diminuiu significativamente após a intervenção nutricional; os biomarcadores analisados foram positivamente impactados, a exceção da concentração de nitrogênio ureico que apresentou tendência de alta após a intervenção nutricional, efeito que pode estar atrelado ao aumento proporcional da ingesta proteica. Conclusão: A proposta de intervenção nutricional apresentou impactos positivos no metabolismo energético dos esquiadores, impactando diretamente na recuperação da fadiga esportiva dos atletas. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.
RESUMEN Introducción: El esquí es un deporte que exige un alto rendimiento de coordinación motora con un elevado consumo de energía, factores que influyen fuertemente en la fatiga muscular. Los deportistas que experimentan este fenómeno, tienden a presentar un descenso en el nivel de rendimiento, generando irritabilidad psicológica y daños en la concentración. La dieta está estrechamente relacionada con el rendimiento deportivo, pero la prescripción adecuada para los atletas de esquí aún carece de estudios. Objetivo: Explorar los métodos de recuperación de la fatiga deportiva en los esquiadores proporcionando perspectivas actualizadas para una intervención nutricional eficaz durante la etapa de recuperación. Métodos: Se seleccionaron siete jóvenes esquiadores varones como sujetos de investigación, y se registró detalladamente la ingesta calórica, entre otras condiciones. Al cabo de tres semanas, se registraron y compararon debidamente los índices de peso corporal, el índice de grasa corporal, el metabolismo sérico, la capacidad cardiopulmonar y el metabolismo energético, entre otros datos relevantes. Resultados: La intervención no tuvo un impacto significativo en los índices de masa corporal magra (p>0,05). El peso corporal de los atletas disminuyó significativamente y el índice de grasa corporal disminuyó significativamente después de la intervención nutricional. Los biomarcadores analizados tuvieron un impacto positivo, con la excepción de la concentración de nitrógeno ureico que mostró una tendencia a aumentar después de la intervención nutricional, efecto que puede estar relacionado con el aumento proporcional de la ingesta de proteínas. Conclusión: La propuesta de intervención nutricional presentó impactos positivos en el metabolismo energético de los esquiadores, impactando directamente en la recuperación de la fatiga deportiva de los atletas. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.
Subject(s)
Humans , Male , Young Adult , Skiing/physiology , Muscle Fatigue/physiology , Nutrition Therapy/methods , Athletic Performance/physiology , Recommended Dietary AllowancesABSTRACT
ABSTRACT Resistance training protocols performed to muscle failure (MF) have been employed in an attempt to maximize activation and neuromuscular fatigue. Therefore, the aim of this study was to compare the surface electromyography amplitude (EMGRMS) and frequency (EMGFREQ) of the pectoralis major between protocols performed to MF and non muscle failure (NMF). Seven trained men performed three sets at 60% of a repetition maximum, with a 3 min rest period and a 6s repetition duration. MF protocol was performing with maximum number of repetitions in all sets, while in NMF protocol subjects performed 6 repetitions in 3 sets. For data analysis two two-way repeated measures ANOVAs (Protocol x Repetition) were used and when necessary, Bonferroni post hoc was performed. The EMGRMS was higher in the protocol MF compare to NMF, but there was no difference in EMGFREQ between protocols. Although there were no significant differences in the frequency domain between protocols, perform repetitions to MF was a determining factor to generate higher amplitude of the electromyography signal. Thus, perform repetitions to MF could be considered an effective strategy to increase muscle activation in trained individuals, however, with similar neuromuscular fatigue.
RESUMO Protocolos de treinamento realizados até a falha muscular (FM) têm sido realizados na tentativa de maximizar a ativação e a fadiga neuromuscular. Portanto, o objetivo deste estudo foi comparar a amplitude do sinal eletromiografico (EMGRMS) e a frequência (EMGFREQ) do peitoral maior entre os protocolos realizados até a FM e sem falha muscular (SFM). Sete homens treinados realizaram três séries com 60% de uma repetição máxima, com um período de descanso de 3 min e uma duração da repetição de 6s. O protocolo FM foi realizado com o número máximo de repetições em todas as séries, enquanto no protocolo SFM os indivíduos realizaram 6 repetições em 3 séries. Para análise dos dados, foram utilizadas duas ANOVAs two-way com medidas repetidas (Protocolo x Repetição) e, quando necessário, foi realizado o post hoc de Bonferroni. Como resultado, a EMGRMS foi maior no protocolo FM comparado ao SFM, mas não houve diferença na EMGFREQ entre os protocolos. Embora não houvesse diferenças significativas no domínio da frequência entre os protocolos, a realização de repetições até a FM foi um fator determinante para gerar maior amplitude do sinal eletromiográfico. Assim, a realização de repetições até a FM pode ser considerada uma estratégia eficaz para aumentar a ativação muscular em indivíduos treinados, porém com fadiga neuromuscular semelhante.
Subject(s)
Humans , Male , Adult , Pectoralis Muscles/physiology , Morbidity , Muscle Fatigue/physiology , Men , Supination/physiology , Range of Motion, Articular/physiology , Electromyography , Resistance Training/instrumentation , Mentoring/methodsABSTRACT
Abstract Aim: To verify the acute effect of sodium bicarbonate (NaHCO3) supplementation on performance during CrossFit® workout. Methods: Nine experienced males (30.8 ± 3.5 years; 84.4 ± 9.5 kg; 177.5 ± 4.03 cm; 2.2 ± 1.0 years) in CrossFit® participated in this study. They were allocated to two conditions: a) supplementation with 0.3 g.kg-1 of body weight of NaHCO3 and b) supplementation with 0.045 g.kg-1 of body weight of sodium chloride (NaCl). Blood lactate was analyzed at two different moments: before (lac-pre) and after the training protocol (lac-post). The heart rate (HR) and the rating of perceived exertion (RPE) were also collected every two minutes during the execution of the training protocol, and the RPE was also collected after it was finished. At the end of the training protocol, a questionnaire to measure gastrointestinal side effects (GSE) was answered by the participants. Repetitions performed in the training protocol was computed to evaluate the performance during the workout. Results: The results showed that there were no differences found when comparing the conditions for all parameters. HR and RPE were different in the first few minutes (< 4-6 minutes) when compared to the final minutes (> 14 minutes) of the workout. The area under the curve of HR and RPE was significantly lower in the NaHCO3 condition. Conclusion: Acute NaHCO3 supplementation did not improve performance during workout 'Cindy' in experienced men. Supplementation also did not alter hemodynamic and perceptual parameters, nor did it cause any GSE. However, responses as a function of time were reduced with NaHCO3 supplementation.
Subject(s)
Humans , Exercise/physiology , Sodium Bicarbonate/administration & dosage , Muscle Fatigue/physiology , Lactic Acid/blood , Surveys and QuestionnairesABSTRACT
Abstract Aim: To compare two different randori structure (high volume and short pauses - TRAD training vs low volume with long pauses - COMP training) in the neuromuscular and metabolic responses of elite judo athletes. Methods: The first situation (TRAD) consisted of 12 randoris of 5 minutes with 45 seconds rest, and the other situation (COMP), consisted of 6 randoris of 5 minutes with 10 minutes between them. Physiological (Blood Lactate and Creatine Kinase), neuromuscular (Countermovement Jump and Medicine Ball Throws) and perceptive variables (Rating Perceived Exertion) were measured before and at the end of the sessions. Results: The subjective perception of effort at the end of the training was significantly higher in the TRAD training type (TRADpost: 8.1 ± 0.9 AU; COMPpost: 6.6 ± 1.5 AU, p <0.001). Blood lactate concentration (TRADpost: 6.4 ± 2.2 mmol/L; COMPpost: 8.1 ± 2.9 mmol/L; p <0.001), CMJ height (TRADpost: 36.2 ± 4.6 cm; COMPpost: 35.9 ± 4.3 cm, p = 0.012) and upper limb power performance (TRADpost: 6.4 ± 0.9 m; COMPpost: 6.3 ± 0.9 m p = 0.03) were significantly higher at the end of the two training sessions compared to their start, but there are no group effect. There is group effect in CK (TRADpost: 490.7 ± 273.5 U/L; COMPpost: 357.4 ± 203.8 U/L; p <0.001). Conclusions: This study demonstrated that TRAD and COMP Judo training induced similar physical demands, and both seem to not be enough to reach higher intensities, which made them distant methods of competitive reality.
Subject(s)
Humans , Exercise/physiology , Martial Arts/physiology , Muscle Fatigue/physiology , Neuromuscular Manifestations , AthletesABSTRACT
ABSTRACT Fatigue is one of the most frequent and disabling symptoms in multiple sclerosis (MS). Central, psychological, and peripheral factors may contribute to the occurrence of fatigue. Objectives: The current study aimed to evaluate potential fatigue determinants in patients with relapsing-remitting MS with a low functional impairment. Methods: We compared inflammatory markers, respiratory pressures, disability, and quality of life in 39 relapsing-remitting MS patients with and without fatigue. Results: Patients with relapsing-remitting MS with fatigue had higher Expanded Disability Status Scale scores (p = 0.002). We observed a significant association between the results of the Guy Neurological Disability Scale, the Functional Assessment of MS Quality of Life Rating Scale and the presence of fatigue (p < 0.05). Conclusions: The degree of functional impairment is a determinant for the presence of fatigue in MS patients, but respiratory function and inflammatory markers are not.
RESUMO A fadiga é um dos sintomas mais frequentes e incapacitantes na esclerose múltipla (EM). Fatores centrais, psicológicos e periféricos podem contribuir para a ocorrência de fadiga. Objetivos: O presente estudo teve como objetivo avaliar potenciais determinantes de fadiga em pacientes com EM remitente-recorrente (EMRR) com baixo nível de incapacidade funcional. Métodos: Foram comparados marcadores inflamatórios, pressões respiratórias, incapacidade e qualidade de vida em 39 pacientes com EMRR com e sem fadiga. Resultados: Pacientes com EMRR com fadiga apresentaram maior Escala de Incapacidade Funcional Expandida (p = 0,002). Observamos uma associação significativa entre os resultados da Escala de Incapacidade Neurológica de Guy e Escala de Avaliação da Qualidade de Vida Funcional com a presença de fadiga (valores de p < 0,05). Conclusão: O grau de comprometimento funcional, mas não a função respiratória e os marcadores inflamatórios, são determinantes para a presença de fadiga em pacientes com EM.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Young Adult , Muscle Fatigue/physiology , Multiple Sclerosis, Relapsing-Remitting/complications , Multiple Sclerosis, Relapsing-Remitting/physiopathology , Fatigue/complications , Fatigue/physiopathology , Psychiatric Status Rating Scales , Quality of Life , Respiration , Severity of Illness Index , Multivariate Analysis , Interleukin-6/blood , Tumor Necrosis Factor-alpha/blood , Statistics, Nonparametric , Disability Evaluation , Maximal Respiratory PressuresABSTRACT
Aim: To investigate the neuromuscular fatigue and recovery after an intermittent isometric handgrip exercise (IIHE) executed until failure with different blood flow restriction (BFR) conditions (free flow, partial and total vascular restriction). Methods: Thirteen healthy men carried out an IIHE at 45% of maximum voluntary isometric force (MVIF) until failure with total restriction (TR), partial restriction (PR) or free flow (FF). The rate of force development (RFD) was extracted from the MIVF over the time intervals of 0-30, 0-50, 0-100, and 0-200ms and normalized by MVIF [relative RFD (RFDr)]. Results: The RFDr decreased significantly (p<0.01) after the IIHE in all BFR conditions and time intervals studied, remaining lower for five minutes. The medians of the RFDr in FF condition were significantly lower (p=0.01) at 30ms (1.56 %MVIF·s-1) and 50ms (1.70 %MVIF·s-1) when compared to TR at 30ms (2.34 %MVIF·s-1) and 50ms (2.63 %MVIF·s-1) in minute 1 post failure. Conclusions: These results show that, regardless of the blood flow restriction level, there is no RFD recovery five minutes after an exhaustive IIHE. When the task was executed with FF, the reduction of the RFD was greater when compared with the TR condition.(AU)
Subject(s)
Humans , Male , Adult , Young Adult , Regional Blood Flow/physiology , Exercise , Muscle Fatigue/physiology , Muscle Strength , Restraint, Physical/methods , HypertrophyABSTRACT
ABSTRACT Motor and non-motor manifestations are common and disabling features of hereditary spastic paraplegia (HSP). Botulinum toxin type A (Btx-A) is considered effective for spasticity and may improve gait in these patients. Little is known about the effects of Btx-A on non-motor symptoms in HSP patients. Objective To assess the efficacy of Btx-A on motor and non-motor manifestations in HSP patients. Methods Thirty-three adult patients with a clinical and molecular diagnosis of HSP were evaluated before and after Btx-A injections. Results Mean age was 41.7 ± 13.6 years and there were 18 women. Most patients had a pure phenotype and SPG4 was the most frequent genotype. The Btx-A injections resulted in a decrease in spasticity at the adductor muscles, and no other motor measure was significantly modified. In contrast, fatigue scores were significantly reduced after Btx-A injections. Conclusion Btx-A injections resulted in no significant functional motor improvement for HSP, but fatigue improved after treatment.
RESUMO Manifestações motoras e não motoras são comuns e incapacitantes nas paraparesias espásticas hereditárias (PEH). Toxina botulínica do tipo A (TB-A) é considerada eficaz no tratamento da espasticidade e pode melhorar a marcha nesses pacientes. Pouco se sabe sobre os efeitos da TB-A sobre sintomas não-motores. Objetivo avaliar a eficácia da TB-A sobre manifestações motoras e não-motoras nas PEH. Método trinta e três pacientes adultos com PEH foram avaliados antes e depois das aplicações de TB-A. Resultados A média de idade foi 41,7 ± 13,6 anos e havia 18 mulheres. A maioria dos pacientes portava a forma pura e o genótipo mais comum foi SPG4. Houve diminuição da espasticidade dos músculos adutores da coxa sem melhora da marcha. A pontuação da fadiga reduziu após as injeções. Conclusão As aplicações de TB-A não melhoraram a marcha nos pacientes mas a redução da fadiga foi significativa após o tratamento.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Spastic Paraplegia, Hereditary/physiopathology , Spastic Paraplegia, Hereditary/drug therapy , Botulinum Toxins, Type A/therapeutic use , Motor Disorders/physiopathology , Motor Disorders/drug therapy , Neuromuscular Agents/therapeutic use , Reproducibility of Results , Treatment Outcome , Age of Onset , Muscle Fatigue/drug effects , Muscle Fatigue/physiology , Gait/drug effects , Gait/physiology , Injections, Intramuscular , Muscle Spasticity/drug therapyABSTRACT
RESUMO Objetivo O principal objetivo deste estudo foi investigar o efeito do tempo de contração e repouso na atividade dos músculos masseter e temporal. Métodos 49 sujeitos do sexo feminino com idade entre 18 e 30 anos foram divididos em grupos DTM (n: 26) e controle (n: 23). A eletromiografia de superfície foi utilizada para avaliar os músculos temporal anterior e masseter durante protocolos de contração e repouso muscular. Foram analisados os parâmetros eletromiográfico raiz quadrada da média, frequência mediana e o coeficiente da inclinação da reta de regressão linear. Resultados Foi encontrado efeito significativo do tempo no protocolo de contração e de repouso muscular. No protocolo de contração, sujeitos com DTM apresentaram significativa diminuição da frequência mediana no masseter direito e do coeficiente de inclinação do músculo temporal direito comparados ao grupo controle. Conclusão Apesar de os sujeitos com DTM apresentarem maior suscetibilidade à fadiga, comparados aos controles, ambos os grupos devem respeitar o tempo máximo de 5 s de contração voluntária máxima e no mínimo 30 s de repouso entre sucessivas contrações da musculatura mastigatória durante protocolos de avaliação clínica ou de pesquisa.
ABSTRACT Purpose The main objective of this study was to investigate the effect of time of contraction and rest on the masseter and temporal muscles activity. Methods 49 female subjects between 18 and 30 years of age were divided into TMD (n: 26) and control groups (n: 23). Surface electromyograph was used to evaluate the anterior temporal and masseter muscles during contraction and rest protocols. The root means square, median frequency and slope coefficient of the linear regression line parameters were analyzed. Results A significant effect of time in the contraction and rest muscle protocols was found. TMD patients showed a significant decrease in median frequency in the right masseter muscle and the slope coefficient in the right temporal muscle during the contraction protocol to control subjects. Conclusion Despite the TMD patients presented with higher fatigue susceptibility compared to the control group, both groups must meet the maximum time of 5 s of maximum voluntary contraction and at least 30 s rest between successive contractions of masticatory muscles during clinical or research assessment protocols.
Subject(s)
Humans , Female , Adolescent , Adult , Young Adult , Temporal Muscle/physiopathology , Temporomandibular Joint Disorders/physiopathology , Masseter Muscle/physiopathology , Muscle Contraction/physiology , Muscle Relaxation/physiology , Reference Values , Time Factors , Case-Control Studies , Cross-Sectional Studies , Analysis of Variance , Statistics, Nonparametric , Muscle Fatigue/physiology , Electromyography , Mastication/physiologyABSTRACT
Abstract Background: Prolonged aerobic exercise, such as running a marathon, produces supraphysiological stress that can affect the athlete's homeostasis. Some degree of transient myocardial dysfunction ("cardiac fatigue") can be observed for several days after the race. Objective: To verify if there are changes in the cardiopulmonary capacity, and cardiac inotropy and lusitropy in amateur marathoners after running a marathon. Methods: The sample comprised 6 male amateur runners. All of them underwent cardiopulmonary exercise testing (CPET) one week before the São Paulo Marathon, and 3 to 4 days after that race. They underwent echocardiography 24 hours prior to and immediately after the marathon. All subjects were instructed not to exercise, to maintain their regular diet, ingest the same usual amount of liquids, and rest at least 8 hours a day in the period preceding the CPET. Results: The athletes completed the marathon in 221.5 (207; 250) minutes. In the post-marathon CPET, there was a significant reduction in peak oxygen consumption and peak oxygen pulse compared to the results obtained before the race (50.75 and 46.35 mL.kg-1 .min-1; 19.4 and 18.1 mL.btm, respectively). The echocardiography showed a significant reduction in the s' wave (inotropic marker), but no significant change in the E/e' ratio (lusitropic marker). Conclusions: In amateur runners, the marathon seems to promote changes in the cardiopulmonary capacity identified within 4 days after the race, with a reduction in the cardiac contractility. Such changes suggest that some degree of "cardiac fatigue" can occur.
Resumo Fundamento: O exercício aeróbico prolongado, como correr uma maratona, produz um estresse suprafisiológico que pode ter impacto na homeostase do atleta. Algum grau de disfunção miocárdica transitória ("fadiga cardíaca") pode ser observado ao longo de vários dias após a prova. Objetivos: Verificar se ocorrem alterações na capacidade cardiopulmonar, no inotropismo e no lusitropismo cardíaco de maratonistas amadores após a realização de uma maratona. Métodos: A amostra foi composta por 6 corredores amadores masculinos. Todos realizaram teste cardiopulmonar de exercício (TCPE) uma semana antes da Maratona de São Paulo e 3 a 4 dias após a mesma. Realizaram ecocardiograma 24 horas antes e imediatamente após a prova. Todos foram orientados a não se exercitar, manter dieta regular, ingerir a mesma quantidade habitual de líquidos e descansar pelo menos 8 horas ao dia no período anterior ao TCPE. Resultados: Os atletas completaram a maratona em 221,5 (207; 250) minutos. No TCPE pós-maratona, ocorreu redução significativa no consumo de oxigênio e no pulso de oxigênio de pico em relação àqueles obtidos antes da prova (50,75 e 46,35 ml.kg-1.min-1; 19,4 e 18,1 ml.btm, respectivamente). Ao ecocardiograma, encontramos redução significativa na onda s' (marcador do inotropismo). A relação E/e' não apresentou alteração significativa após a maratona (marcador do lusitropismo). Conclusões: Em atletas amadores, a maratona parece promover alterações na capacidade cardiopulmonar identificadas pelo menos em até 4 dias após a prova, com redução na contratilidade e, portanto, no inotropismo cardíaco. Tais modificações sugerem que algum grau de "fadiga cardíaca" possa ocorrer.
Subject(s)
Humans , Male , Adult , Middle Aged , Heart/physiology , Muscle Fatigue/physiology , Oxygen Consumption/physiology , Running/physiology , Echocardiography , Exercise Test , Myocardial Contraction/physiology , Reference Values , Statistics, Nonparametric , Time Factors , Ventricular FunctionABSTRACT
O objetivo deste estudo foi avaliar o limiar de dor a pressão (LDP) e a percepção de dor orofacial através do teste de fadiga mastigatória após um período de inatividade da mastigação. Estudo caracterizado como de coorte, prospectivo e observacional. Composto por 30 indivíduos obesos mórbidos, divididos em dois grupos. Experimental (GE) (n=15) que foram submetidos a cirurgia bariátrica e Controle (GC) (n=15) que se apresentavam na fase pré cirúrgica. O Limiar de Dor a Pressão e a Escala de Análise Visual (EAV) foram adotados como testes para compor a avaliação de fadiga mastigatória. Os dados foram registrados em dois tempos distintos para ambos os grupos, com um intervalo de 37 dias entre as coletas. No entanto, apenas o GE foi submetido a inatividade mastigatória. Empregou-se o teste de Shapiro-Wilk para avaliar a normalidade dos dados e adotou-se ANOVA mista de medidas repetidas (dados paramétricos) e o teste de Friedman (dados não paramétricos) para identificar diferenças intragrupos e para comparar os valores de LDP observados antes e depois da cirurgia bariátrica foram empregados o teste t de Student para amostras pareadas (dados paramétricos) e o teste de Wilcoxon pareado (dados não paramétricos) considerando-se uma probabilidade de erro do tipo I () de 0,05. Para o GE, os níveis do LDP apresentaram uma redução significativa e a percepção de dor aumentou durante o teste de fadiga mastigatória quando avaliado após o período de inatividade da mastigação. Outro dado observado foi a não recuperação dos níveis do LDP e EAV após a o teste de fadiga, no qual os níveis não retornaram aos registros iniciais como no período pré cirúrgico. Diante dos dados avaliados no teste de fadiga mastigatória, o Limiar de Dor a Pressão apresentou reduções significativas, caracterizando o aumento da sensibilidade à palpação nos músculos avaliados, após o período de inatividade mastigatória de 37 dias. Ao passo que houve aumento na percepção de dor orofacial dos pacientes obesos mórbidos no mesmo período de avaliação.(AU)
The aim of this study was to evaluate the pressure pain threshold (PPT) and the perception of orofacial pain through masticatory fatigue test after a period of inactivity of mastication. Study characterized as a cohort, prospective, observational. Composed of 30 morbid obese subjects, separated into two groups: Experimental (EG) (n = 15) were submitted to bariatric surgery and Control (CG) (n = 15) pre surgical procedure. The Pressure Pain Threshold and Visual Analysis Scale (VAS) have been adopted as testing to compose the evaluation of masticatory fatigue. Data were recorded at two different times for both groups, with an interval of 37 days between the analyses. However only the EG was subjected to masticatory inactivity. The Shapiro-Wilk test was employed to assess the normality of the data and adopted mixed repeated measures ANOVA (parametric data) and the Friedman test (nonparametric data) to identify intergroup differences and to compare the PPT values observed before and after bariatric surgery were used the Student t test for paired samples (parametric data) and Wilcoxon test (nonparametric data) considering a probability of error type I () of 0.05. For EG, the PPT levels showed a significant reduction and the perception of pain increased during the masticatory fatigue test when evaluated after a period of inactivity of mastication. Another fact observed was the non-recovery of the PPT and VAS levels after the fatigue test, in which the levels did not return to the original records as the surgical pre surgical procedure. According the data evaluated in the masticatory fatigue test, the pain threshold to pressure showed significant reductions, featuring increased tenderness to palpation in the muscles evaluated after masticatory inactivity period of 37 days. Whereas there was an increase in the perception of orofacial pain of morbidly obese patients in the same period of evaluation.(AU)
Subject(s)
Humans , Male , Female , Bariatric Surgery , Facial Pain/physiopathology , Mastication/physiology , Masticatory Muscles/physiopathology , Muscle Fatigue/physiology , Obesity, Morbid/surgery , Pain Threshold/physiology , Analysis of Variance , Obesity, Morbid/physiopathology , Observational Study , Pain Measurement , Postoperative Period , Preoperative Period , Prospective Studies , Statistics, Nonparametric , Time FactorsABSTRACT
This study aimed to identify useful electronic grip dynamometry parameters to track differences between trained (TR) and untrained (UT) participants, and between dominant (DO) and non-dominant (ND) limbs as a consequence of upper limbs muscle fatigue following 10 RM tests of the brachial biceps. This experimental study with transversal design involved 18 young adult males, of whom 9 were untrained and 9 were experienced in resistance training. Isometric grip force was evaluated (30 seconds long) previous and after 10RM tests by means of a G200 Model grip dynamometer with precision load cell (Biometrics(r)). Significant differences between initial and final measurements were found only for trained participants: Peak force for TR-DO (67.1 vs 55.5 kgf, p = .0277); Raw average for TR-DO (46.96 vs 42.22 kgf, p = .0464), and for TR-ND (40.34 vs 36.13 kgf, p = .0277). Electronic grip dynamometry efficiently identified upper limbs fatigue in trained participants, being raw average measurements the best parameter.
Objetivou-se identificar parâmetros da dinamometria eletrônica de preensão palmar úteis para monitorar diferenças entre indivíduos treinados (TR) e não treinados (UT) e entre membros dominantes (DO) e não dominantes (ND) após indução de fadiga pelo teste de 10RM para bíceps braquial. Tratou-se de estudo experimental, transversal, envolvendo 18 homens adultos jovens, 9 não treinados e 9 experientes em treinamento resistido. Avaliou-se a força isométrica de preensão palmar (por 30 segundos) antes e após o teste de 10 RM por dinamômetro de preensão com célula de carga de precisão modelo G200 (Biometrics(r)). Houve diferença significativa entre valores iniciais e finais somente para treinados: Pico de força para TR-DO (67,1 vs 55,5 kgf, p = 0,0277); média bruta para TR-DO (46,96 vs 42,22 kgf, p = 0,0464) e para TR-ND (40,34 vs 36,13 kgf, p = 0,0277). A dinamometria eletrônica mostrou-se eficaz em identificar a fadiga de membros superiores nos participantes treinados, sendo a média bruta o melhor parâmetro.
El objetivo fue identificar los parámetros en la dinamometría electrónica de presión palmar para comprobar las diferencias en individuos entrenados (TR) y no entrenados (UT) y en miembros dominantes (DO) y no dominantes (ND) después de la fatiga inducida por la prueba de 10RM para bíceps braquial. Fue estudio experimental, transversal que incluyó 18 hombres adultos jóvenes, 9 no entrenados y 9 con experiencia en entrenamiento resistido. La fuerza isométrica de presión palmar (durante 30 segundos) después de la prueba de 10RM fue evaluada por dinamómetro de presión con célula de carga de precisión modelo G200 (Biometrics(r)). Fue encontrada significativa entre los valores iniciales y finales sólo para el grupo entrenados: fuerza máxima para TR-DO (67,1 vs 55,5 kgf, p = 0,0277); promedio bruto para TR-DO (46,96 vs 42,22 kgf, p = 0,0464) y para TR-ND (40,34 vs 36,13 kgf, p = 0,0277). El dinamómetro electrónico fue eficaz en la identificación de la fatiga de los miembros superiores en los participantes entrenados, con el mejor parámetro promedio bruto.
Subject(s)
Humans , Male , Adult , Muscle Strength Dynamometer , Muscle Fatigue/physiology , Hand Strength/physiology , Resistance TrainingABSTRACT
The purpose of this study was to determine the effect of respiratory muscle fatigue on intercostal and forearm muscle perfusion and oxygenation in patients with heart failure. Five clinically stable heart failure patients with respiratory muscle weakness (age, 66±12 years; left ventricle ejection fraction, 34±3%) and nine matched healthy controls underwent a respiratory muscle fatigue protocol, breathing against a fixed resistance at 60% of their maximal inspiratory pressure for as long as they could sustain the predetermined inspiratory pressure. Intercostal and forearm muscle blood volume and oxygenation were continuously monitored by near-infrared spectroscopy with transducers placed on the seventh left intercostal space and the left forearm. Data were compared by two-way ANOVA and Bonferroni correction. Respiratory fatigue occurred at 5.1±1.3 min in heart failure patients and at 9.3±1.4 min in controls (P<0.05), but perceived effort, changes in heart rate, and in systolic blood pressure were similar between groups (P>0.05). Respiratory fatigue in heart failure reduced intercostal and forearm muscle blood volume (P<0.05) along with decreased tissue oxygenation both in intercostal (heart failure, -2.6±1.6%; controls, +1.6±0.5%; P<0.05) and in forearm muscles (heart failure, -4.5±0.5%; controls, +0.5±0.8%; P<0.05). These results suggest that respiratory fatigue in patients with heart failure causes an oxygen demand/delivery mismatch in respiratory muscles, probably leading to a reflex reduction in peripheral limb muscle perfusion, featuring a respiratory metaboreflex.
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Heart Failure/physiopathology , Intercostal Muscles/metabolism , Muscle Fatigue/physiology , Muscle, Skeletal/metabolism , Oxygen Consumption/physiology , Reflex/physiology , Respiratory Muscles/metabolism , Blood Flow Velocity/physiology , Blood Pressure/physiology , Blood Volume/physiology , Forearm , Heart Rate/physiology , Physical Exertion , Respiratory Muscles/physiopathologyABSTRACT
This study aimed to determine and analyze the neuromuscular fatigue onset by median frequency (MDF) and the root mean square (RMS) behavior of an electromyographic signal (EMG). Eighteen healthy men with no prior knee problems initially performed three maximum voluntary isometric contractions (MVIC). After two days of MVIC test, participants performed a fatiguing protocol in which they performed submaximal knee-extension contractions at 20% and 70% MVIC held to exhaustion. The MDF and RMS values from the EMG signals were recorded from the vastus medialis (VM) and the vastus lateralis (VL). Analysis of the MDF and RMS behavior enabled identification of neuromuscular fatigue onset for VM and VL muscles in 20% and 70% loads. Alterations between the VM and VL in the neuromuscular fatigue onset, at 20% and 70% MVIC, were not significant. These findings suggest that the methodology proposal was capable of indicating minute differences sensible to alterations in the EMG signals, allowing identification of the moment when the MDF and the RMS showed significant changes in behavior. The methodology used was also a viable one for describing and identifying the neuromuscular fatigue onset by means of the analysis of EMG signals...
Este estudo teve como objetivo determinar e analisar o início da fadiga neuromuscular pelo comportamento do sinal de eletromiográfico (EMG) da frequência mediana (FM) e do root mean square (RMS). Dezoito homens saudáveis, sem problemas no joelho, realizaram inicialmente três contrações isométricas voluntárias máximas (CVMs). Após dois dias de CVM os sujeitos realizaram um protocolo de fadiga em que realizaram contrações submáximas de extensão do joelho em 20% e 70% da CVM até a exaustão. Os valores dos sinais de FM e RMS foram registrados a partir do vasto medial (VM) e vasto lateral (VL). A análise do comportamento da FM e RMS permitiu a identificação do início da fadiga neuromuscular para os músculos VM e VL em 20% e 70% da carga máxima. Alterações entre o VM e VL no início da fadiga neuromuscular, com 20% e 70% do MVIC, não foram significativas. Estes resultados sugerem que a metodologia proposta foi capaz de indicar diferenças mínimas sensíveis a alterações nos sinais EMG, permitindo a identificação do momento em que a FM e o RMS apresentaram mudanças significativas no seu comportamento. A metodologia utilizada também foi viável para descrever e identificar o aparecimento da fadiga neuromuscular por meio de análise de sinais de EMG...
Este estudio tieve como objetivo determinar y analizar la aparición de fatiga neuromuscular por la frecuencia media (FM) y la media de la raíz cuadrada (RMS) de lo señal electromiográfico (EMG). Dieciocho hombres saludables que no tienen problemas de rodilla previas inicialmente realizaron tres contracciones máximas voluntarias (CVM). Después de dos días de CVM los sujetos realizaron un protocolo de fatiga en la que se presentaron submáximas de extensión de rodilla en 20% y el 70% CVM hasta el agotamiento. Los valores de FM y RMS de las señales EMG se registraron desde el vasto medial (VM) y el vasto lateral (VL). Análisis del comportamiento de FM y RMS activado identificación de inicio fatiga neuromuscular para VM y músculos VL y 20% y el 70 % de la carga maxima. Las alteraciones entre el VM y VL en el inicio de la fatiga neuromuscular, en el 20% y el 70% de la CVM, no fueron significativas. Estos hallazgos sugieren que la propuesta de metodología fue capaz de indicar las diferencias minutos sensibles a las alteraciones en las señales de EMG, que permitan identificar el momento en que el FM y el RMS mostraron cambios significativos en el comportamiento. La metodología utilizada fue también una opción viable para la descripción y la identificación de la aparición de fatiga neuromuscular por medio del análisis de las señales de EMG...
Subject(s)
Humans , Male , Adult , Muscle Fatigue/physiology , Isometric Contraction , Quadriceps Muscle/physiology , Electromyography/methodsABSTRACT
OBJECTIVE: This study sought to analyze the effect of muscle fatigue induced by active isotonic resistance training at a moderate intensity by measuring the knee extension motion during the stabilometric response in a single-leg stance among healthy university students who perform resistance training on a regular basis. METHOD: Eleven healthy university students were subjected to a one-repetition maximum (1RM) test. In addition, stabilometric assessment was performed before and after the intervention and consisted of a muscle fatiguing protocol, in which knee extension was selected as the fatiguing task. The Shapiro-Wilk test was used to investigate the normality of the data, and the Wilcoxon test was used to compare the stabilometric parameters before and after induction of muscle fatigue, at a significance level of p≤0.05. Descriptive statistics were used in the analysis of the volunteers' age, height, body mass, and body mass index (BMI). RESULTS: The sample population was 23.1±2.7 years of age, averaged 1.79.2±0.07 m in height and 75.6±8.0 Kg in weight, and had a BMI of 23.27±3.71 Kg.m-2. The volunteers performed exercises 3.36±1.12 days/week and achieved a load of 124.54±22.07 Kg on 1RM and 74.72±13.24 Kg on 60% 1RM. The center of pressure (CoP) oscillation on the mediolateral plane before and after fatigue induction was 2.89±0.89 mm and 4.09±0.59 mm, respectively, while the corresponding values on the anteroposterior plane were 2.5±2.2 mm and 4.09±2.26 mm, respectively. The CoP oscillation amplitude on the anteroposterior and mediolateral planes exhibited a significant difference before and after fatigue induction (p=0.04 and p=0.05, respectively). CONCLUSIONS: The present study showed that muscle fatigue affects postural control, particularly with the mediolateral and anteroposterior CoP excursion. .
OBJETIVO: Analisar o efeito da fadiga muscular induzida por exercício isotônico ativo-resistido de extensão de joelhos em intensidade moderada na resposta estabilométrica em apoio unipodal em universitários saudáveis, praticantes de treinamento resistido. MÉTODO: Para tanto, 11 jovens universitários saudáveis foram submetidos ao teste de 1-RM, avaliação estabilométrica pré e pós-intervenção e protocolo de indução à fadiga muscular utilizando a extensão do joelho como tarefa fatigante. Utilizou-se o teste de Shapiro-Wilk para verificação da normalidade dos dados e o teste de Wilcoxon para as comparações entre os parâmetros estabilométricos pré e pós-indução à fadiga muscular com nível de significância estipulado em p≤0,05, enquanto a estatística descritiva foi aplicada para caracterizar a idade, estatura, massa corporal e o índice de massa corporal (IMC). RESULTADOS: O grupo apresentou 23,1±2,7 anos; 1,79,2±0,07 m; 75,6±8,0 Kg; 23,27±3,71 Kg.m-2; 3,36±1,12 número de dias de atividade/semana; 1RM: 124,54± 22,07 kg; 60% de 1-RM: 74,72±13,24 Kg. A oscilação do centro de pressão (CP) médio-lateral pré e pós-fadiga, respectivamente, foi de 2,89±0,89 mm e 4,09±0,59 mm, enquanto a oscilação ântero-posterior foi de 2,5±2,2 mm e 4,09±2,26 mm. Encontrou-se diferença na largura de oscilação do CP nas direções ântero-posterior e médio-lateral entre as condições pré e pós-fadiga, p=0,04 e p=0,05, respectivamente. CONCLUSÕES: Portanto, o estudo demonstrou que a fadiga muscular altera o controle postural, especialmente na excursão médio-lateral e ântero-posterior do CP. .
Subject(s)
Humans , Male , Young Adult , Leg/physiology , Muscle Fatigue/physiology , Postural Balance/physiology , Resistance TrainingABSTRACT
O objetivo deste estudo foi analisar o número de repetições sustentadas até a falha concêntrica, em séries múltiplas de exercícios com pesos. Três séries a 70% de 1-RM foram executadas por 17 homens (28,0 ± 5,1 anos), nos exercícios supino em banco horizontal, agachamento, rosca direta, cadeira extensora e mesa flexora, com dois minutos de recuperação entre as séries e cinco minutos entre os exercícios. Um maior número total de repetições (p < 0,05) foi identificado nos exercícios multiarticulares (33 repetições) em relação aos exercícios monoarticulares (24 a 28 repetições). Uma redução significante no desempenho (p < 0,05) foi encontrada entre a primeira e a segunda série (28 a 35%) e entre a segunda e a terceira série (22 a 36%). Os resultados sugerem que o desempenho motor não é sustentado em séries múltiplas a 70% de 1-RM em exercícios monoarticulares e multiarticulares, com intervalos de recuperação de dois minutos.
The aim of this study was to analyze the number of repetitions to concentric failure sustained in multiple sets of weight exercises. Three sets of 1-RM were performed by 17 men (28.0 ± 5.1 years) in bench press, squat, arm curl, leg extension, and leg curl exercises, with rest period of 2-min between sets and 5-min between exercises. A larger number of total repetitions (p < 0.05) was identified in multiple-joint (33 repeats) compared to single-joint exercises (24 to 28 repetitions). A significant reduction in performance (p < 0.05) was found between the first and second set (28 to 35) and between the second and third set (22 to 36). The results suggest that the motor performance is not sustained in multiple sets the 70% of 1-RM in single- and multiple-joint exercises, with rest periods of 2-min.
El objetivo de este estudio fue analizar el número de repeticiones sostenidas hasta la falla concéntrica en series múltiples de ejercicios con pesas. Tres series a 70% de 1-RM fueron ejecutadas por 17 hombres (28.0 ± 5,1 años), en los ejercicios press de banco, sentadilla, curl con barra in pie, extensión de piernas y curl de piernas tendido, con dos minutos de descanso entre as series y cinco minutos entre el ejercicios. Un mayor número de repeticiones (p < 0.05) fue identificado en el ejercicios multiarticulares (33 repeticiones) en comparación con monoarticulares (24 a 28 repeticiones). Una reducción significativa en el desempeño (p < 0.05) fue encontrado entre la primera y segunda serie (28 a 35) y entre la segunda y tercera serie (22 a 36). Los resultados sugieren que el desempeño motor no se sustenta en series múltiples a 70% de 1-RM en ejercicios monoarticulares y multiarticulares, con intervalos de dos minutos de recuperación.
Subject(s)
Humans , Male , Adult , Motor Activity/physiology , Muscle Fatigue/physiology , Muscle StrengthABSTRACT
Objetivo: Analisar os efeitos do esforço físico de partida de futebol na capacidade funcional e estabilidade dos membros inferiores em jovens jogadores de futebol. Métodos: foram analisados 10 atletas jogadores de futebol submetidos a avaliação da capacidade funcional dos membros inferiores através de um protocolo de Hop Test e avaliação do nível de estabilidade postural através do Biodex Stability System (Biodex, Inc., Shirley, Nova Iorque), antes e imediatamente após um tempo de jogo amistoso de futebol de campo com duração de 45 minutos. Resultados: após a partida, ocorreu uma diminuição no índice de estabilidade global (F(1,23) = 7,29 P = .024) e índice anteroposterior (APSI) (F(1,23) = 5,53 P = .043). A fadiga no membro dominante foi a responsável pelo déficit significativo no OSI (F(1,23) = 3.16, P = .047) e APSI (F(1,23) = 3.49, P = .029), enquanto o membro não-dominante não gerou qualquer alteração na condição pré e pós- jogo. Conclusão: uma partida de futebol pode causar diminuição da estabilidade e capacidade funcional dos membros inferiores em jovens jogadores. Nível de Evidência III, Pré-teste e Pós-teste (Caso-controle).
Objective: Analyze the effects of physical exertion during a soccer match on the functional capacity and stability of the lower limbs of young soccer players. Methods: we analyzed 10 soccer players who underwent functional capacity assessment of the lower limbs by a Hop Test protocol and evaluation of the level of postural stability in the Biodex Stability System (Biodex, Inc., Shirley, NY) before and immediately after a friendly game lasting 45 minutes. Results: after the match, there was a decrease in overall stability index (F (1,23) = 7.29 P = .024) and anterior posterior index (APSI) (F(1,23) = 5.53 P = .043). Fatigue in the dominant limb was responsible for the significant deficit in OSI F(1,23) = 3.16, P = .047)and APSI (F(1,23) = 3:49, P = .029), while the non-dominant limb did not cause any change in the pre and post-game. Conclusion: a football match can cause decreased stability and functional capacity of the lower limbs in young players. Level of Evidence III, Pre-test and Post-test Study (Case-control).
Subject(s)
Humans , Male , Athletic Injuries , Postural Balance/physiology , Lower Extremity/injuries , Muscle Fatigue/physiology , Soccer/injuries , Analysis of Variance , Surveys and Questionnaires , Data Interpretation, StatisticalABSTRACT
OBJETIVO: Avaliar o efeito de dois Intervalos de Recuperação (IR) no pico de torque (PT) e no trabalho total (TT) isocinético em mulheres jovens. MÉTODOS: 17 mulheres, destreinadas, (27,2 ± 4,1 anos; 56,8 ± 6,9 kg; 162,6 ± 7,0 cm) realizaram três séries de 10 extensões isocinéticas do joelho a 60° e 180°/s, com um e dois minutos de IR. A análise estatística foi a ANOVA dois x três [IR (um e dois minutos) x série (1ª, 2ª e 3ª)] com α < 0.05. RESULTADOS: Um minuto de IR não foi suficiente para manter o PT e o TT ao longo das séries (p<0,05) a 60º (redução de 15,7% no PT e 19,8% no TT) e 180º/s (redução de 3,6% no PT e de 5,6% no TT). Dois minutos foram suficientes apenas a 180º/s. Contudo, a 60°/s, dois minutos de IR possibilitou um maior PT na segunda e na terceira série em relação a um minuto (p<0,05). CONCLUSÃO: Dois minutos são suficientes para manutenção do PT em um protocolo de treinamento isocinético a 180º/s, mas não a 60º/s em mulheres jovens.
OBJECTIVE: To examine the effect of two rest interval (RI) on isokinetic Peak Torque (PT) and total work (TW) produced by young women. METHODS: 17 untrained women (27.2 ± 4.1 yrs; 56.8 ± 6.9 kg; 162.6 ± 7.0 cm) performed three sets of 10 unilateral isokinetic knee extension repetitions at 60° and 180°/s with one and two minutes of RI. Statistical evaluation was performed using a two x three ANOVA [RI (one and two minutes) x set (1st, 2nd, 3rd)] with α < 0.05. RESULTS: One minute was not enough to keep PT and TW between sets (p<0.05) at 60º (reduction of 15.7% in PT and 19.8% in TW) and 180º/s (reduction of 3.6% in PT and 5.6% in TT). Two minutes was enough only at 180º/s. However, two minutes of RI was greater (p<0.05) than one minutes at 60°/s for PT during the 2nd and 3rd sets. CONCLUSION: Two minutes is sufficient to keep PT within typical isokinetic resistance training protocols at 180º/s, but not at 60º/s in young women.
Subject(s)
Humans , Male , Adult , Knee Joint/physiology , Isometric Contraction/physiology , Muscle Fatigue/physiology , Muscle Strength/physiology , TorqueABSTRACT
Determinou-se o limiar anaeróbico (V4) de 23 cavalos Crioulos hígidos em treinamento. Os animais selecionados foram submetidos a testes de desempenho, composto por três etapas de velocidade progressiva de 6m/s, 8m/s e 10m/s, com duração de cinco minutos cada etapa, até que fosse atingida a concentração de 4mmol/dL de lactato sanguíneo. As concentrações de lactato sanguíneo elevaram-se a partir da velocidade de exercício de 6,0m/s, sendo que 20 animais (90%) atingiram 4mmol/L de lactato na velocidade entre 6 - 8m/s, com média de frequência cardíaca que variou de 121 a 140bpm. Concluiu-se que a V4 do cavalo Crioulo está entre as velocidades de 6 - 8m/s e a frequência cardíaca entre 121 - 140bpm.
The anaerobic threshold (V4) while running on a track is used in many breeds to evaluate physical conditioning and to establish a training regimen, but these data have not been obtained for the Crioulo breed. This study evaluated 23 healthy Crioulo horses to determine the anaerobic threshold (V4) during training. The selected animals were subjected to a performance test on a track. The test consisted of three five minute stages with increasing speeds of 6m/s, 8 m/s and 10m/s until the blood lactate concentration reached 4mmol/dL. Blood lactate concentrations began to increase at the exercise speed of 6m/s, and 90% (n=20) of the animals reached 4mmol/dL lactate between 6-8m/s, with an average heart rate ranging from 121 to 140bpm at these speeds. Our results demonstrate that the V4 of the Crioulo horse is between 6-8m/s at a heart rate between 121 and 140bpm.