RESUMEN
BACKGROUND/OBJECTIVES: The oral administration of hydrolyzed collagen peptides is a scientifically validated intervention for enhancing skeletal muscle health and performance. This integrative review consolidates the evidence supporting the use of low molecular weight collagen peptides (2000-3500 daltons) for their superior bioavailability and absorption. Our objective was to review the effects of collagen peptide or hydrolyzed collagen supplementation on muscle damage, recovery, and construction related to physical exercise. METHODS: A bibliographic search was conducted in major English-language databases, including PubMed/Medline, using terms like "Peptides Collagen and Damage" and "collagen peptides AND Soreness Muscle". This review followed PRISMA guidelines, with bias risk assessed via the PEDro scale. The inclusion criteria were (a) randomized clinical trials, (b) randomized studies in humans with a control or placebo group, (c) studies assessing muscle damage or delayed onset muscle soreness via physiological markers or strength performance tests, and (d) studies using hydrolyzed collagen or collagen peptides. RESULTS: Initially, 752 articles were identified. After applying the inclusion and exclusion criteria, including duplicate removal, eight articles with 286 participants were included. Of these, 130 participants received collagen peptide supplementation, while 171 received a placebo or control. CONCLUSION: This integrative review supports the potential of collagen peptide supplementation to mitigate muscle stress from acute strenuous resistance training. However, due to the methodological heterogeneity among the studies, further clinical trials are needed to clarify the mechanisms underlying muscle improvement with collagen supplementation.
Asunto(s)
Colágeno , Suplementos Dietéticos , Músculo Esquelético , Mialgia , Humanos , Músculo Esquelético/efectos de los fármacos , Mialgia/tratamiento farmacológico , Péptidos/farmacología , Péptidos/administración & dosificación , Entrenamiento de Fuerza , Fatiga Muscular/efectos de los fármacos , Ensayos Clínicos Controlados Aleatorios como Asunto , Fuerza Muscular/efectos de los fármacos , Masculino , Adulto , Femenino , Ejercicio FísicoRESUMEN
The use of creatine monohydrate (Cr) in professional soccer is widely documented. However, the effect of low doses of Cr on the physical performance of young soccer players is unknown. This study determined the effect of a low dose of orally administered Cr on muscle power after acute intra-session fatigue in young soccer players. Twenty-eight young soccer players (mean age = 17.1 ± 0.9 years) were randomly assigned to either a Cr (n = 14, 0.3 g·kg-1·day-1 for 14 days) or placebo group (n = 14), using a two-group matched, double-blind, placebo-controlled design. Before and after supplementation, participants performed 21 repetitions of 30 m (fatigue induction), and then, to measure muscle power, they performed four repetitions in half back squat (HBS) at 65% of 1RM. Statistical analysis included a two-factor ANOVA (p Ë 0.05). Bar velocity at HBS, time: p = 0.0006, Åp2 = 0.22; group: p = 0.0431, Åp2 = 0.12, time × group p = 0.0744, Åp2 = 0.02. Power at HBS, time: p = 0.0006, Åp2 = 0.12; group: p = 0.16, Åp2 = 0.06, time × group: p = 0.17, Åp2 = 0.009. At the end of the study, it was found that, after the induction of acute intra-session fatigue, a low dose of Cr administered orally increases muscle power in young soccer players.
Asunto(s)
Creatina , Suplementos Dietéticos , Fatiga Muscular , Fuerza Muscular , Fútbol , Humanos , Fútbol/fisiología , Creatina/administración & dosificación , Adolescente , Método Doble Ciego , Masculino , Fatiga Muscular/efectos de los fármacos , Administración Oral , Fuerza Muscular/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Rendimiento Atlético/fisiología , AtletasRESUMEN
Creatine is consumed by athletes to increase strength and gain muscle. The aim of this study was to evaluate the effects of creatine supplementation on maximal strength and strength endurance. Twelve strength-trained men (25.2 ± 3.4 years) supplemented with 20 g Creatina + 10g maltodextrin or placebo (20g starch + 10g maltodextrin) for five days in randomized order. Maximal strength and strength endurance (4 sets 70% 1RM until concentric failure) were determined in the bench press. In addition, blood lactate, rate of perceived effort, fatigue index, and mood state were evaluated. All measurements were performed before and after the supplementation period. There were no significant changing in maximal strength, blood lactate, RPE, fatigue index, and mood state in either treatment. However, the creatine group performed more repetitions after the supplementation (Cr: Δ = +3.4 reps, p = 0.036, g = 0.53; PLA: Δ = +0.3reps, p = 0.414, g = 0.06), and higher total work (Cr: Δ = +199.5au, p = 0.038, g = 0.52; PLA: Δ = +26.7au, p = 0.402, g = 0.07). Creatine loading for five days allowed the subjects to perform more repetitions, resulting in greater total work, but failed to change the maximum strength.
Asunto(s)
Creatina , Suplementos Dietéticos , Ácido Láctico , Fuerza Muscular , Resistencia Física , Humanos , Masculino , Adulto , Creatina/administración & dosificación , Creatina/farmacología , Creatina/sangre , Fuerza Muscular/efectos de los fármacos , Fuerza Muscular/fisiología , Resistencia Física/efectos de los fármacos , Resistencia Física/fisiología , Ácido Láctico/sangre , Adulto Joven , Entrenamiento de Fuerza/métodos , Fatiga Muscular/efectos de los fármacos , Fatiga Muscular/fisiología , Método Doble CiegoRESUMEN
ABSTRACT Introduction: The quest for better sports performance or simply for esthetic ends has led individuals to seek ergogenic resources indiscriminately to attain their goals. It is believed that nutritional supplements promote better strength, power, focus and better reaction time. Nutritional supplements are used to delay fatigue and increase athletic performance. Also, the anorectics, drugs derived from amphetamines and commonly sought for weight loss, act on the central nervous system by releasing substances that transmit the sensation of not being hungry. Supplements that promise quick solutions to these goals may have compounds in their formulas that compromise health. Objectives: In this study, the potential of creatine and Jack 3D® to boost physical performance and delay muscle fatigue was evaluated in animals that were given the supplements. Methods: The animals underwent 10 weeks of swim training at 80% of the maximum load and received creatine and/or Jack 3D. The muscle contractions were recorded by an electrophysiograph for analysis of muscle fatigue. Results: It was observed that the SED+CR group had significantly different values compared to the SED group and NAT+CR group showed significant differences between groups for the SED, SED+JACK, JACK, NAT and NAT+JACK groups (p <0.05). For the two last parameters, the SED group showed a significant difference in relation to the SED+CR, NAT and NAT+CR groups (p <0.05). Conclusions: These results demonstrate a possible positive influence of physical exercise associated with the use of creatine, delaying muscle fatigue and making an increase in sports performance possible. Level of Evidence III; Development of diagnostic criteria in consecutive patients (with "gold" reference standard applied) .
RESUMEN Introducción: La búsqueda por el mejor desempeño deportivo o simplemente para fines estéticos ha inducido a los individuos a buscar indiscriminadamente recursos ergogénicos para alcanzar el éxito. Se cree que la ingestión de suplementos nutricionales puede proporcionar mayor resistencia, potencia, enfoque y mejor tiempo de reacción. Los suplementos nutricionales son empleados para retardar el surgimiento de la fatiga y aumentar el desempeño atlético. También comúnmente buscados para adelgazamiento están los anorexígenos, medicamentos a base de drogas anfetamínicas, que actúan sobre el sistema nervioso central liberando sustancias que transmiten la sensación de ausencia de hambre. Los suplementos que prometen soluciones rápidas para estos objetivos pueden presentar en sus fórmulas, compuestos que comprometen la salud. Objetivo: En este estudio fue evaluado el potencial de la creatina y del Jack3D® para el desempeño físico y la fatiga muscular de los animales que recibieron la suplementación. Métodos: Los animales fueron sometidos a 10 semanas de entrenamiento de natación a 80% de la carga máxima y recibieron creatina y/o Jack3D. Las contracciones musculares fueron registradas por un electrofisiógrafo para análisis de la fatiga muscular. Resultados: Se observó que el grupo SED+CR presentó valores significativamente diferentes en comparación con el grupo SED y el grupo NAT+CR presentó diferencias significativas con relación a los grupos SED, SED+JACK, NAT y NAT+JACK (p < 0,05). En los dos últimos parámetros, el grupo SED presentó diferencia significativa con relación a los grupos SED+CR, NAT y NAT+CR (p < 0,05). Conclusión: Esos resultados demuestran una posible influencia positiva del ejercicio físico asociado al uso de la creatina, retardando la fatiga muscular y posibilitando un aumento en el desempeño deportivo. Nivel de evidencia III; Desarrollo de criterios diagnósticos en pacientes consecutivos (con estándar de referencia "oro" aplicado) .
RESUMO Introdução: A busca pelo melhor rendimento esportivo ou simplesmente para fins estéticos tem induzido indivíduos a procurarem indiscriminadamente recursos ergogênicos para atingir o êxito. Acredita-se que a ingestão de suplementos nutricionais pode proporcionar maior resistência, potência, foco e melhor tempo de reação. Os suplementos nutricionais são empregados afim de retardar o surgimento da fadiga e aumentar o desempenho atlético. Também comumente procuradas para emagrecimento estão os anorexígenos, medicamentos à base de drogas anfetamínicas, que agem sobre o sistema nervoso central liberando substâncias que transmitem a sensação de ausência de fome. Suplementos que prometem soluções rápidas para estes objetivos podem conter em suas fórmulas compostos que comprometem a saúde. Objetivos: Neste estudo foi avaliado o potencial da creatina e do Jack 3D®para o desempenho físico e fadiga muscular dos animais que receberam a suplementação. Métodos: Os animais foram submetidos a 10 semanas de treinamento de natação a 80% da carga máxima e receberam creatina e/ou Jack 3D. As contrações musculares foram registradas por um eletrofisiógrafo para análise da fadiga muscular. Resultados: Observou-se que o grupo SED+CR apresentou valores significativamente diferentes em comparação com o Grupo SED e o Grupo NAT+CR apresentou diferenças significativas com relação aos grupos SED, SED+JACK, NAT e NAT+JACK (p < 0,05). Nos dois últimos parâmetros, o Grupo SED apresentou diferença significativa com relação aos grupos SED+CR, NAT e NAT+CR (p < 0,05). Conclusão: Esses resultados demonstram uma possível influência positiva do exercício físico associado ao uso da creatina, retardando a fadiga muscular e possibilitando um aumento no desempenho esportivo. Nível de Evidência III; Desenvolvimento de critérios diagnósticos em pacientes consecutivos (com padrão de referência "ouro" aplicado) .
Asunto(s)
Animales , Masculino , Ratones , Condicionamiento Físico Animal , Natación , Fatiga Muscular/efectos de los fármacos , Suplementos Dietéticos , Creatina/administración & dosificación , Rendimiento Físico Funcional , Modelos AnimalesRESUMEN
ABSTRACT Introduction: The use of substances to enhance sports performance among professional and amateur athletes is increasing. Such substances may either be included in the group of dietary supplements or fall into pharmacological classes. Every substance used for this purpose is called an ergogenic agent. The number of ergogenic options available increases every day, favoring overuse and use without proper guidance. Among the dietary supplements, we highlight the use of creatine, a substance widespread in sports. Among the pharmacological groups, many drugs are used. Recently the use of sildenafil citrate by professional athletes from various predominantly aerobic sports modalities was reported in the media. Objective: To compare and demonstrate the responses caused by physical training associated with the use of creatine and sildenafil citrate in mice. Methods: A swim training protocol was applied and then an electrophysiograph was used in order to obtain parameters related to contraction intensity, the area under the curve and the percentage drop. Results: The responses obtained demonstrated the ergogenic action of creatine because it altered the parameters used for measurement. The use of sildenafil citrate did not yield satisfactory results to frame the drug as an ergogenic agent. Conclusion: Creatine has an ergogenic effect, reducing the percentage drop after 10 seconds, while sildenafil demonstrated no ergogenic potential and, interestingly, resulted in weaker responses when compared to the exercise groups. Evidence level II; Comparative prospective study .
RESUMEN Introducción: El uso de sustancias con el objetivo de aumentar el rendimiento deportivo entre atletas profesionales y amateurs es creciente. Tales sustancias pueden formar parte del grupo de suplementos alimentarios o integrar clases farmacológicas. Toda sustancia empleada para ese fin es denominada agente ergogénico. El número de opciones entre los agentes ergogénicos aumenta cada día, favoreciendo así su uso excesivo y sin la debida orientación. Entre los suplementos alimentarios, se destaca el uso de creatina, sustancia muy difundida en el medio deportivo. Ya entre los grupos farmacológicos, muchas sustancias son usadas. Recientemente, fue divulgado entre los medios de comunicación el uso de citrato de sildenafil por atletas profesionales, de varias modalidades deportivas, predominantemente las aeróbicas. Objetivos: Comparar y demostrar las respuestas ocasionadas por el entrenamiento físico, asociadas al uso de creatina y citrato de sildenafil en ratones. Métodos: Se aplicó un protocolo de entrenamiento de natación y, a continuación, se usó un electrofisiógrafo con el objetivo de obtener parámetros referentes a la intensidad de contracción, al área bajo la curva y a la caída porcentual. Resultados: Las respuestas obtenidas demuestran acción ergogénica de la creatina, visto que alteraron los parámetros empleados para la medición. Ya el uso de citrato de sildenafil no presentó resultados satisfactorios para encuadrar al fármaco como agente ergogénico. Conclusión: La creatina presenta efecto ergogénico porque reduce la caída porcentual después de 10 segundos, mientras que el sildenafil no presentó potencial ergogénico y, curiosamente, demostró respuestas inferiores cuando comparado a los grupos de ejercicio. Nivel de evidencia II; Estudio prospectivo comparativo .
RESUMO Introdução: O uso de substâncias com o objetivo de aumentar o rendimento esportivo entre atletas profissionais e amadores é crescente. Tais substâncias podem fazer parte do grupo de suplementos alimentares ou integrar classes farmacológicas. Toda substância empregada para esse fim é denominada de agente ergogênico. O número de opções entre os agentes ergogênicos aumenta a cada dia, favorecendo assim o uso em demasia e sem a devida orientação. Entre os suplementos alimentares, salientamos a utilização de creatina, substância muito difundida no meio esportivo. Já entre os grupos farmacológicos, muitas substâncias são utilizadas. Recentemente, foi divulgado entre os meios de comunicação o uso de citrato de sildenafila por atletas profissionais de várias modalidades esportivas, predominantemente as aeróbicas. Objetivos: Comparar e demonstrar as repostas ocasionadas pelo treinamento físico, associadas ao uso de creatina e citrato de sildenafila em camundongos. Métodos: Aplicou-se um protocolo de treinamento de natação e, a seguir, empregou-se um eletrofisiógrafo com objetivo de obter parâmetros referentes à intensidade de contração, à área sob a curva e à queda percentual. Resultados: As respostas obtidas demonstram ação ergogênica da creatina, visto que alteraram os parâmetros empregados para a mensuração. Já a utilização de citrato de sildenafila não apresentou resultados satisfatórios para enquadrar o fármaco como agente ergogênico. Conclusão: A creatina apresenta efeito ergogênico porque reduz a queda percentual após 10 segundos, já a sildenafila não apresentou potencial ergogênico e, curiosamente, demonstrou respostas inferiores quando comparado aos grupos de exercício. Nível de evidência II; Estudo prospectivo comparativo .
Asunto(s)
Animales , Masculino , Ratones , Natación , Vasodilatadores/farmacología , Fatiga Muscular/efectos de los fármacos , Creatina/farmacología , Citrato de Sildenafil/farmacología , Rendimiento Físico Funcional , Nervio Ciático/cirugía , Tendones/cirugía , Modelos Animales , Electrofisiología/instrumentaciónRESUMEN
ABSTRACT Fatigue is a comprehensive process that involves many physiological and biochemical factors. It is a normal physiological reaction when human physical or mental activities reach a certain level. In recent years, it has been verified that free radicals are closely related to exercise-induced fatigue. Cardamine bursa purified selenoprotein has good oxygen-free radical scavenging ability and anti-lipid peroxide. It could protect mitochondria, liver, and red blood cells from peroxide injury. Therefore, it was speculated that the purification of selenoprotein Cardamine may play an active role in attenuating exercise-induced fatigue by scavenging free radicals. This study cleared the selenite protein Capsella bursa (SPC) as a research object, and evaluated its structural characteristics in relieving exercise-induced fatigue. The selenoprotein index system for exercise-induced fatigue was constructed by combining two AHP methods, principal component analysis and factor analysis. Purity, subunit composition, amino acid composition and RCM content were evaluated. The corresponding RCM protein was preliminarily predicted. The results showed that SPCH could significantly prolong the swimming time (P <0.01), improve the lactate clearance capacity (P <0.01), increase the glycogen content of the liver (P <0.01), and reduce the level of the BUN (P <0.05). SPCH has a good effect in relieving exercise-induced fatigue in mice, so it can be considered for development as a nutritional supplement to alleviate exercise-induced fatigue.
RESUMO Fadiga é um processo abrangente envolvendo muitos fatores fisiológicos e bioquímicos. É uma reação fisiológica normal quando as atividades físicas ou mentais humanas atingem um certo nível. Nos últimos anos, verificou-se que os radicais livres estão intimamente relacionados com a fadiga induzida pelo exercício. A selenoproteina purificada de Cardamina bursa tem boa capacidade de depuração de radicais sem oxigénio e de peróxido anti-lípido. Poderia proteger as mitocôndrias, fígado e glóbulos vermelhos de lesões por peróxido. Por conseguinte, especulou-se que a purificação da selenoproteina de Cardamina pode desempenhar um papel activo na atenuação da fadiga induzida pelo exercício por meio de radicais livres de scavenging. Este estudo depurou a proteína selenita Capsella bursa (SPC) como objeto de pesquisa, e avaliou as suas características estruturais no alívio da fadiga induzida pelo exercício. O sistema de índice de selenoproteinas para a fadiga induzida pelo exercício foi construído por meio da combinação dos métodos de AHP, análise principal de componentes e a análise de fatores. Foram avaliados a pureza, a composição sub-unitária, a composição de aminoácidos e o conteúdo do RCM. A proteína correspondente do RCM foi prevista preliminarmente. Os resultados mostraram que o SPCH poderia prolongar significativamente o tempo de natação (P < 0.01), melhorar a capacidade de depuração do lactato (P< 0.01), aumentar o conteúdo do glicogênio do fígado (P < 0.01), e reduzir o nível do BUN (P< 0.05). o SPCH tem um bom efeito em aliviar a fadiga induzida pelo exercício em ratos, de modo que pode ser considerado para desenvolvê-lo como um suplemento nutricional para aliviar a fadiga induzida pelo exercício.
RESUMEN La fatiga es un proceso abarcador que envuelve muchos factores fisiológicos y bioquímicos. Es una reacción fisiológica normal cuando las actividades físicas o mentales humanas alcanzan un cierto nivel. En los últimos anos, se verificó que los radicales libres están íntimamente relacionados con la fatiga inducida por el ejercicio. La selenoproteína purificada de Cardamina bursa tiene buena capacidad de depuración de radicales sin oxígeno y de peróxido antilipídico. Podría proteger las mitocondrias, el hígado y los glóbulos rojos de lesiones por peróxido. Por consiguiente, se especuló que la purificación de la selenoproteína de Cardamina puede desempeñar un papel activo en la atenuación de la fatiga inducida por el ejercicio por medio de radicales libres de scavenging. Este estudio depuró la proteína selenita Capsella bursa (SPC) como objeto de investigación, y evaluó sus características estructurales en el alivio de la fatiga inducida por el ejercicio. El sistema de índice de selenoproteínas para a fatiga inducida por el ejercicio fue construido por medio de la combinación dos métodos de AHP, el análisis principal de componentes y el análisis de factores. Fueron evaluados la pureza, la composición sub-unitaria, la composición de aminoácidos y el contenido del RCM. La proteína correspondiente del RCM fue prevista preliminarmente. Los resultados mostraron que el SPCH podría prolongar significativamente el tiempo de natación (P < 0.01), mejorar la capacidad de depuración del lactato (P< 0.01), aumentar el contenido del glicógeno del hígado (P < 0.01), y reducir el nivel del BUN (P< 0.05). el SPCH tiene un buen efecto en aliviar la fatiga inducida por el ejercicio en ratones, de modo que puede ser considerado para desarrollarlo como un suplemento nutricional para aliviar la fatiga inducida por el ejercicio.
Asunto(s)
Animales , Masculino , Femenino , Ratones , Fatiga Muscular/efectos de los fármacos , Cardamine/química , Selenoproteínas/farmacología , Fatiga/prevención & control , Condicionamiento Físico Animal , Natación , Radicales Libres , Peróxidos LipídicosRESUMEN
O naproxeno, assim como outros anti-inflamatórios não esteroides (AINEs), está entre os medicamentos mais prescritos no mundo. O objetivo do presente estudo é analisar o efeito da ingestão de naproxeno em parâmetros neuromusculares e determinar seu efeito no dano muscular por meio do uso do marcador lactato. Metodologicamente, foi conduzido um estudo cruzado randomizado, duplo-cego e controlado por placebo em 11 homens treinados em resistência, que realizaram uma sessão de treinamento de força após ingerir 500 mg de naproxeno e outra sessão de treinamento após ingerir um placebo. Os participantes realizaram três séries de supino horizontal com uma carga de 90% da repetição máxima (1RM) até a falha concêntrica. As variáveis de resultado incluíram número de repetições, carga de trabalho e lactato. Os resultados mostraram que há uma correlação positiva e moderada entre as variáveis somatório de repetições e carga total e entre as variáveis lactato e carga total, no grupo naproxeno. No grupo placebo, a correlação positiva e moderada deu-se entre somatório de repetições e carga total. Na análise magnitude baseada nas interferências, as variáveis se mostraram possíveis para uma probabilidade positiva ou trivial e improvável para uma probabilidade negativa. Concluiu-se no presente estudo que o uso do naproxeno como recurso ergogênico no treinamento de força reduz a percepção de fadiga, mas não tem efeito direto no dano muscular, analisado a partir do marcador lactato, logo não interfere de maneira significativa nos parâmetros neuromusculares analisados.
Naproxen, as other non-steroidal anti-inflammatory drugs (NSAIDs), features among the most widely prescribed drugs in the world. The aim of this study is to analyze the effect of naproxen intake on neuromuscular parameters and determine its effect on muscle damage through the use of the lactate marker. In terms of methodology, a randomized, double-blind, placebo-controlled crossover study was conducted on 11 resistance-trained men who underwent a strength training session after taking 500 mg of naproxen and another training session after taking a placebo. The participants performed three sets of horizontal bench presses with a load of 90% maximum repetition (1RM) until concentric failure. Result variables included number of repetitions, workload and lactate. The results showed that there is a positive and moderate correlation between the sum of repetition and total load variables and between lactate and total load variables in the naproxen group. In the placebo group, a positive and moderate correlation was observed between sum of repetitions and total load. In the magnitude analysis, based on the interferences, the variables were shown to be possible for a positive or trivial probability and unlikely for a negative probability. It was concluded that the use of naproxen as an ergogenic resource in strength training reduces the perception of fatigue but has no direct effect on muscle damage when analyzed from the lactate marker, therefore it does not significantly interfere in the analyzed neuromuscular parameters.
Asunto(s)
Humanos , Masculino , Adulto , Antiinflamatorios no Esteroideos/farmacología , Naproxeno/farmacología , Fatiga Muscular/efectos de los fármacos , Fuerza Muscular/efectos de los fármacos , Fármacos Neuromusculares/farmacología , Supinación , Método Doble Ciego , Entrenamiento de Fuerza , Sustancias para Mejorar el Rendimiento/farmacología , Lactatos/sangre , Músculos/metabolismoRESUMEN
NEW FINDINGS: What is the central question of this study? Does creatine supplementation augment the total torque impulse accumulated above end-test torque (IET) during severe-intensity knee-extensor exercise by attenuating the rate of decrease in peak potentiated twitch torque (PT)? What is the main finding and its importance? Creatine augmented the IET and attenuated the rate of decrease in both voluntary activation and PT during severe-intensity exercise. The IET was related to the rate of decrease in PT. These findings reveal an important role for the rates of neuromuscular fatigue development as key determinants of exercise tolerance within the severe domain. ABSTRACT: This study investigated the effect of creatine supplementation on exercise tolerance, total torque impulse accumulated above end-test torque (total IET) and neuromuscular fatigue development of the knee extensors during severe-intensity intermittent isometric exercise. Sixteen men were randomly allocated into Creatine (n = 8, 20 g day-1 for 5 days) or Placebo (n = 8) groups and performed knee-extensor maximal voluntary contraction (MVC) testing, all-out testing to determine end-test torque (ET) and the finite torque impulse accumulated above end-test torque (IET'), and three submaximal tests at ET + 10%: (i) time to task failure without supplementation (Baseline); (ii) time to task failure after creatine or placebo supplementation; and (iii) time matched to Baseline after creatine (Creatine-Isotime) or placebo (Placebo-Isotime) supplementation. Creatine supplementation significantly increased the time to task failure (Baseline = 572 ± 144 s versus Creatine = 833 ± 221 s) and total IET (Baseline = 5761 ± 1710 N m s versus Creatine = 7878 ± 1903 N m s), but there were no significant differences within the Placebo group. The percentage change pre- to postexercise in MVC, voluntary activation, peak potentiated twitch torque and integrated EMG during MVC were not significantly different between Baseline and Creatine but were all significantly attenuated in Creatine-Isotime compared with Baseline. There were no significant differences in these variables within the placebo group. The total IET was significantly correlated with the rates of change in potentiated twitch torque peak (r = 0.83-0.87) and rate of torque development (r = -0.83 to -0.87) for the submaximal tests to task failure. These findings reveal an important role for the rates of neuromuscular fatigue development as key determinants of exercise tolerance during severe-intensity intermittent isometric exercise.
Asunto(s)
Creatina/administración & dosificación , Ejercicio Físico/fisiología , Contracción Isométrica/efectos de los fármacos , Fatiga Muscular/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Adulto , Suplementos Dietéticos , Tolerancia al Ejercicio/efectos de los fármacos , Humanos , Articulación de la Rodilla/efectos de los fármacos , Masculino , Contracción Muscular/efectos de los fármacos , TorqueRESUMEN
The aim of the present study was to analyze the effect of creatine (Cr) supplementation on peak torque (PT) and fatigue rate in Paralympic weightlifting athletes. Eight Paralympic powerlifting athletes participated in the study, with 25.40 ± 3.30 years and 70.30 ± 12.15 kg. The measurements of muscle strength, fatigue index (FI), peak torque (PT), force (kgf), force (N), rate of force development (RFD), and time to maximum isometric force (time) were determined by a Musclelab load cell. The study was performed in a single-blind manner, with subjects conducting the experiments first with placebo supplementation and then, following a 7-day washout period, beginning the same protocol with creatine supplementation for 7 days. This sequence was chosen because of the lengthy washout of creatine. Regarding the comparison between conditions, Cr supplementation did not show effects on the variables of muscle force, peak torque, RFD, and time to maximum isometric force (p > 0.05). However, when comparing the results of the moments with the use of Cr and placebo, a difference was observed for the FI after seven days (U3: 1.12; 95% CI: (0.03, 2.27); p = 0.02); therefore, the FI was higher for placebo. Creatine supplementation has a positive effect on the performance of Paralympic powerlifting athletes, reducing fatigue index, and keeping the force levels as well as PT.
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Creatina/administración & dosificación , Suplementos Dietéticos , Fatiga Muscular/efectos de los fármacos , Fuerza Muscular/efectos de los fármacos , Músculo Esquelético/fisiología , Paratletas , Fenómenos Fisiológicos en la Nutrición Deportiva/fisiología , Levantamiento de Peso/fisiología , Adulto , Brasil , Creatina/farmacología , Humanos , Contracción Isométrica/efectos de los fármacos , Masculino , Método Simple Ciego , Torque , Adulto JovenRESUMEN
The influence of cyclists' performance levels on caffeine-induced increases in neuromuscular fatigue after a 4-km cycling time trial (TT) was investigated. Nineteen cyclists performed a 4-km cycling TT 1 h after ingesting caffeine (5 mg·kg-1) or placebo (cellulose). Changes from baseline to after exercise in voluntary activation (VA) and potentiated 1 Hz force twitch (Qtw,pot) were used as markers of central and peripheral fatigue, respectively. Participants were classified as "high performing" (HP, n = 8) or "low performing" (LP, n = 8) in accordance with their performance in a placebo trial. Compared with placebo, caffeine increased the power, anaerobic mechanical power, and anaerobic work, reducing the time to complete the trial in both groups (p < 0.05). There was a group versus supplement and a group versus supplement versus trial interaction for Qtw,pot, in which the postexercise reduction was greater after caffeine compared with placebo in the LP group (Qtw,pot = -34% ± 17% vs. -21% ± 11%, p = 0.02) but not in the HP group (Qtw,pot = -22% ± 8% vs. -23% ± 10%, p = 0.64). There was no effect of caffeine on VA, but there was a group versus trial interaction with lower postexercise values in the LP group than in the HP group (p = 0.03). Caffeine-induced improvement in 4-km cycling TT performance seems to come at the expense of greater locomotor muscle fatigue in LP but not in HP cyclists. Novelty Caffeine improves exercise performance at the expense of a greater end-exercise peripheral fatigue in low-performing athletes. Caffeine-induced improvement in exercise performance does not affect end-exercise peripheral fatigue in high-performing athletes. High-performing athletes seem to have augmented tolerance to central fatigue during a high-intensity time trial.
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Ciclismo/fisiología , Cafeína/farmacología , Fatiga Muscular/efectos de los fármacos , Adulto , Rendimiento Atlético , Estudios Cruzados , Suplementos Dietéticos , Método Doble Ciego , Humanos , Masculino , Músculo Esquelético/fisiología , Resistencia FísicaAsunto(s)
Rendimiento Atlético/fisiología , Suplementos Dietéticos , Tolerancia al Ejercicio/efectos de los fármacos , Tolerancia al Ejercicio/fisiología , beta-Alanina/administración & dosificación , Carnosina/metabolismo , Humanos , Fatiga Muscular/efectos de los fármacos , Fatiga Muscular/fisiología , Músculo Esquelético/metabolismoRESUMEN
The study investigated the influence of ß-alanine supplementation during a high-intensity interval training (HIIT) program on repeated sprint ability (RSA) performance. This study was randomized, double-blinded, and placebo controlled. Eighteen men performed an incremental running test until exhaustion (TINC) at baseline and followed by 4-wk HIIT (10 × 1-min runs 90% maximal TINC velocity [1-min recovery]). Then, participants were randomized into two groups and performed a 6-wk HIIT associated with supplementation of 6.4 g/day of ß-alanine (Gß) or dextrose (placebo group; GP). Pre- and post-6-wk HIIT + supplementation, participants performed the following tests: 1) TINC; 2) supramaximal running test; and 3) 2 × 6 × 35-m sprints (RSA). Before and immediately after RSA, neuromuscular function was assessed by vertical jumps, maximal isometric voluntary contractions of knee extension, and neuromuscular electrical stimulations. Muscle biopsies were performed to determine muscle carnosine content, muscle buffering capacity in vitro (ßmin vitro), and content of phosphofructokinase (PFK), monocarboxylate transporter 4 (MCT4), and hypoxia-inducible factor-1α (HIF-1α). Both groups showed a significant time effect for maximal oxygen uptake (Gß: 6.2 ± 3.6% and GP: 6.5 ± 4.2%; P > 0.01); only Gß showed a time effect for total (-3.0 ± 2.0%; P = 0.001) and best (-3.3 ± 3.0%; P = 0.03) RSA times. A group-by-time interaction was shown after HIIT + Supplementation for muscle carnosine (Gß: 34.4 ± 2.3 mmol·kg-1·dm-1 and GP: 20.7 ± 3.0 mmol·kg-1·dm-1; P = 0.003) and neuromuscular voluntary activation after RSA (Gß: 87.2 ± 3.3% and GP: 78.9 ± 12.4%; P = 0.02). No time effect or group-by-time interaction was shown for supramaximal running test performance, ßm, and content of PFK, MCT4, and HIF-1α. In summary, ß-alanine supplementation during HIIT increased muscle carnosine and attenuated neuromuscular fatigue, which may contribute to an enhancement of RSA performance.NEW & NOTEWORTHY ß-Alanine supplementation during a high-intensity interval training program increased repeated sprint performance. The improvement of muscle carnosine content induced by ß-alanine supplementation may have contributed to an attenuation of central fatigue during repeated sprint. Overall, ß-alanine supplementation may be a useful dietary intervention to prevent fatigue.
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Fatiga Muscular/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , beta-Alanina/administración & dosificación , Adulto , Carnosina/metabolismo , Suplementos Dietéticos , Método Doble Ciego , Ejercicio Físico/fisiología , Prueba de Esfuerzo/métodos , Entrenamiento de Intervalos de Alta Intensidad/métodos , Humanos , Contracción Isométrica/efectos de los fármacos , Masculino , Músculo Esquelético/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Carrera/fisiologíaRESUMEN
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.
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Toxinas Botulínicas Tipo A/uso terapéutico , Trastornos Motores/tratamiento farmacológico , Trastornos Motores/fisiopatología , Fármacos Neuromusculares/uso terapéutico , Paraplejía Espástica Hereditaria/tratamiento farmacológico , Paraplejía Espástica Hereditaria/fisiopatología , Adulto , Edad de Inicio , Femenino , Marcha/efectos de los fármacos , Marcha/fisiología , Humanos , Inyecciones Intramusculares , Masculino , Persona de Mediana Edad , Fatiga Muscular/efectos de los fármacos , Fatiga Muscular/fisiología , Espasticidad Muscular/tratamiento farmacológico , Espasticidad Muscular/fisiopatología , Reproducibilidad de los Resultados , Resultado del TratamientoRESUMEN
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.
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Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Paraplejía Espástica Hereditaria/fisiopatología , Paraplejía Espástica Hereditaria/tratamiento farmacológico , Toxinas Botulínicas Tipo A/uso terapéutico , Trastornos Motores/fisiopatología , Trastornos Motores/tratamiento farmacológico , Fármacos Neuromusculares/uso terapéutico , Reproducibilidad de los Resultados , Resultado del Tratamiento , Edad de Inicio , Fatiga Muscular/efectos de los fármacos , Fatiga Muscular/fisiología , Marcha/efectos de los fármacos , Marcha/fisiología , Inyecciones Intramusculares , Espasticidad Muscular/tratamiento farmacológicoRESUMEN
The link between total work performed above critical power (CP) and peripheral muscle fatigue during self-paced exercise is unknown. We investigated the influence of caffeine on the total work done above CP during a 4-km cycling time trial (TT) and the subsequent consequence on the development of central and peripheral fatigue. Nine cyclists performed three constant-load exercise trials to determine CP and two 4-km TTs ~75 min after oral caffeine (5 mg/kg) or cellulose (placebo) ingestion. Neuromuscular functions were assessed before and 50 min after supplementation and 1 min after TT. Oral supplementation alone had no effect on neuromuscular function ( P > 0.05). Compared with placebo, caffeine increased mean power output (~4%, P = 0.01) and muscle recruitment (as inferred by EMG, ~17%, P = 0.01) and reduced the time to complete the TT (~2%, P = 0.01). Work performed above CP during the caffeine trial (16.7 ± 2.1 kJ) was significantly higher than during the placebo (14.7 ± 2.1 kJ, P = 0.01). End-exercise decline in quadriceps twitch force (pre- to postexercise decrease in twitch force at 1 and 10 Hz) was more pronounced after caffeine compared with placebo (121 ± 13 and 137 ± 14 N vs. 146 ± 13 and 156 ± 11 N; P < 0.05). There was no effect of caffeine on central fatigue. In conclusion, caffeine increases muscle recruitment, which enables greater work performed above CP and higher end-exercise peripheral locomotor muscle fatigue. NEW & NOTEWORTHY The link between total work done above critical power and peripheral fatigue during a self-paced, high-intensity exercise is unclear. This study revealed that caffeine ingestion increases muscle recruitment, which enables greater work done above critical power and a greater degree of end-exercise decline in quadriceps twitch force during a 4-km cycling time trial. These findings suggest that caffeine increases performance at the expense of greater locomotor muscle fatigue.
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Rendimiento Atlético , Cafeína/farmacología , Estimulantes del Sistema Nervioso Central/farmacología , Fatiga Muscular/efectos de los fármacos , Esfuerzo Físico/efectos de los fármacos , Adulto , Ciclismo , Ejercicio Físico , Humanos , MasculinoRESUMEN
Sodium citrate (SCit) supplementation has been studied for several years as a strategy to reduce the muscle fatigue induced by H+ ion accumulation within the skeletal muscle during high-intensity, short-duration exercise. Several investigations have been published on this matter, and appear to indicate that SCit is not effective as an ergogenic aid, despite its ability to increase extracellular buffering capacity. In this short report, we briefly discuss the SCit results previously published in the literature and consider them in light of new and promising findings, which appear to address issues associated with previous study designs. We also suggest possible reasons for the current lack of reported ergogenic effects from this nutritional strategy and make recommendations that may re-define research in this area.
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Citratos/farmacología , Suplementos Dietéticos , Fatiga Muscular/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Sustancias para Mejorar el Rendimiento/farmacología , Humanos , Músculo Esquelético/fisiología , Citrato de SodioRESUMEN
BACKGROUND: The practice of prolonged exercise with high intensity, as seen in triathlon training, can cause physiological imbalances that might result in muscle fatigue, muscle damage and changes in systemic inflammatory response, thus reduce the athletes' physical performance, therefore, both adequate total caloric and macronutrient intake also the use of a specific ergogenic aid, as taurine supplementation would be an alternative to prevent inflammation and muscle damage. In order to verify the effects of 8 weeks of taurine and chocolate milk supplementation, markers of muscle damage, inflammation, and aerobic capacity were quantified in triathletes. METHODS: A double-blind, crossover, randomized study was conducted with 9 male long-distance triathletes, aged 25-35 years. Supplementation of 3 g of taurine (TAU) or placebo (PLA) associated with 400 mL low fat chocolate milk was performed during an 8-week period. In order to verify the effects of the supplementation protocol markers of muscle damage as lactate dehydrogenase (LDH) and creatine kinase (CK), and inflammatory markers tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were quantified, also triathletes' performance was evaluated by exhaust test on a treadmill. RESULTS: It was observed a significant increase in taurine and CK plasma levels after TAU supplementation (P=0.02 and P=0.01, respectively). However, LDH concentrations did not differ significantly after the supplementations performed, and there were no changes in physical performance parameters; anaerobic threshold, perceived exertion, heart rate, and the concentrations of IL-6 and TNF-α. CONCLUSIONS: Taurine supplementation did not provide benefits on performance and muscle damage in triathletes.
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Ciclismo , Suplementos Dietéticos , Tolerancia al Ejercicio/efectos de los fármacos , Fatiga Muscular/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Carrera , Natación , Taurina/administración & dosificación , Adulto , Rendimiento Atlético/fisiología , Biomarcadores/sangre , Creatina Quinasa/sangre , Estudios Cruzados , Método Doble Ciego , Humanos , Inflamación , Interleucina-6/sangre , L-Lactato Deshidrogenasa/sangre , Masculino , Taurina/sangre , Factor de Necrosis Tumoral alfa/sangre , Adulto JovenRESUMEN
People seek a greater quality of life and healthy aging that culminates in improved self-esteem and vitality in the performance of daily activities; this is generating a growing number of people enrolled in gyms in search of quick results. However, this training can result in physical and metabolic damage. During physical exercise, under conditions of oxidative stress, changes take place that lead to the onset of fatigue. The Agaricus brasiliensis mushroom is native to Brazil and has therapeutic potential, with widely studied antioxidant and immunomodulatory capabilities. However, little is known about its potential benefits regarding muscular strength. Therefore, this study evaluated the possible effects of supplementation with this mushroom with respect to strength performance before and after a resistance training session. A blinded randomized trial was performed with male volunteers (n = 5) randomly divided into 2 groups (placebo and treatment with A. brasiliensis). Perceptions of muscle soreness and performance were assessed before and after high-intensity resistance training sessions. The study was executed over a 24-day period. Promising results were found related to intrasession rapid strength, most likely a result of antioxidant action and redox balance. The bioactive compounds in A. brasiliensis revealed the potential to improve conditions of muscle fatigue without altering other parameters. Thus, this mushroom has become a target of great expectations in the fields of fitness and athletics.
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Agaricus , Antioxidantes/uso terapéutico , Suplementos Dietéticos , Factores Inmunológicos/uso terapéutico , Fatiga Muscular/efectos de los fármacos , Humanos , Masculino , Estrés Oxidativo/efectos de los fármacos , Acondicionamiento Físico Humano , Calidad de VidaRESUMEN
The effects of citrulline malate (CM) on muscle recovery from resistance exercise remains unknown. We aimed to determine if citrulline malate supplementation improves muscle recovery after a single session of high-intensity resistance exercise (RE) in untrained young adult men. Nine young adult men (24.0 ± 3.3 years) participated in a double-blind crossover study in which they received 6 g of CM and placebo (PL) on two occasions, separated by a seven-day washout period. Each occasion consisted of a single session of high-intensity RE (0 h) and three subsequent fatigue tests sessions (at 24, 48, and 72 h) to assess the time course of muscle recovery. During the tests sessions, we assessed the following variables: number of maximum repetitions, electromyographic signal (i.e., root mean square (RMS) and median frequency (MF)), muscle soreness and perceived exertion, as well as blood levels of creatine kinase (CK), lactate, insulin, and testosterone:cortisol ratio. CK levels increased at 24 h post-exercise and remained elevate at 48 and 72 h, with no difference between CM and PL conditions. Muscle soreness increased at 24 h post-exercise, which progressively returned to baseline at 72 h in both conditions. Lactate levels increased immediately post-exercise and remained elevated at 24, 48, and 72 h in both conditions. No significant treatment × time interaction was found for all dependents variables (maximum repetitions, perceived exertion, CK, lactate, RMS, MF, and testosterone:cortisol ratio) during the recovery period. In conclusion, our data indicate that CM supplementation (single 6 g dose pre-workout) does not improve the muscle recovery process following a high-intensity RE session in untrained young adult men.
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Citrulina/análogos & derivados , Suplementos Dietéticos , Malatos/uso terapéutico , Contracción Muscular , Fatiga Muscular/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Entrenamiento de Fuerza , Adulto , Biomarcadores/sangre , Citrulina/efectos adversos , Citrulina/uso terapéutico , Creatina Quinasa/sangre , Estudios Cruzados , Suplementos Dietéticos/efectos adversos , Método Doble Ciego , Humanos , Hidrocortisona/sangre , Ácido Láctico/sangre , Malatos/efectos adversos , Masculino , Músculo Esquelético/metabolismo , Recuperación de la Función , Testosterona/sangre , Factores de Tiempo , Resultado del Tratamiento , Adulto JovenRESUMEN
AIMS: The current study tested the hypotheses that 1) an acute bout of aerobic exercise impairs isolated skeletal muscle contractile properties and 2) N-acetylcysteine (a thiol antioxidant; NAC) administration can restore the impaired muscle contractility after exercise. MAIN METHODS: At rest or immediately after an acute bout of aerobic exercise, extensor digitorum longus (EDL) and soleus muscles from male Wistar rats were harvested for ex vivo skeletal muscle contraction experiments. Muscles from exercised animals were incubated in Krebs Ringer's buffer in absence or presence of 20mM of NAC. Force capacity and fatigue properties were evaluated. KEY FINDINGS: Exercised EDL and soleus displayed lower force production across various stimulation frequencies (p<0.001), indicating that skeletal muscle force production was impaired after an acute bout of exercise. However, NAC treatment restored the loss of force production in both EDL and soleus after fatiguing exercise (p<0.05). Additionally, NAC treatment increased relative force production at different time points during a fatigue-induced protocol, suggesting that NAC treatment mitigates fatigue induced by successive contractions. SIGNIFICANCE: NAC treatment improves force capacity and fatigue properties in ex vivo skeletal muscle from rats submitted to an acute bout of aerobic exercise.