The present study investigated the hypothesis that maximal voluntary contractions (MVC) peak torque, VJ, muscle tenderness, and plasma creatine activity would be significantly less for the condition that subjects were exposed to hypoxic (H) condition for 4 hours after eccentric exercise compared with the normoxic (N) condition.

The aims of the studies undertaken were to investigate the physiological and serum biochemical changes associated with muscle damage, and to test possible treatments for this condition. Initial studies examined the effects of walking 37 km daily for 4 days and of running 21.1 km and 25.6 km road race events in different groups of subjects. Prolonged walking produced little soreness, but daily increases in serum creatine kinase (CK) activity were recorded. In the two running studies, delayed increases in the serum activity of the enzymes CK, lactate dehydrogenase (LD) and aspartate transaminase (AST) were observed, as were changes in the CK and LD isoenzyme pattern. In a further study, the CK-MM isoform response to a maximal eccentric arm exercise was studied in 8 subjects. Although total CK activity continued to increase for 5 days after exercise, the CK MM1:MM3 ratio peaked at 48 h after exercise, when muscle soreness also peaked. Two non-steroidal anti-inflammatory drugs were assessed for their effectiveness in the muscle soreness condition. Diclofenac and ibuprofen were tested in double-blind crossover studies in which drug or placebo were administered before and after two bouts of 45 minutes downhill running. Neither drug proved effective in reducing muscle soreness or serum enzyme changes after the eccentric exercise. The effect of prior vitamin C supplementation on the same parameters was assessed, but this treatment also proved ineffective. A final study examined the effect of exercise during the period of muscle soreness and damage. In this study, a light eccentric exercise bout was performed 24 h after a heavy eccentric bout, using the same arm muscles. Performance of the light bout did not alter the symptoms of muscle soreness, but did effect serum CK activity changes and resistance to muscle fatigue during later eccentric exercise.

No description available.

Intermittent Pneumatic Compression (IPC) use as a tool for recovery after exercise has recently become widespread among athletes. While there is strong anecdotal support for IPC, little research has been done to show its effectiveness in recovery. Eight collegiate football athletes were recruited and subjected to IPC or control conditions in a randomized crossover manner during off-season training. Countermovement jump (CMJ) and 10m sprint were evaluated before training, at 3 and 24 hours following training. Self-reported soreness, blood markers of inflammation [interleukin-6, interleukin-10, and monocyte chemoattractant protein-1 (MCP-1)] and muscle damage (myoglobin) were measured before training, post-training, post-recovery and at 3 and 24 hours post-training. Significant time effects were observed in MCP-1 and myoglobin (p < 0.05) indicating an inflammatory response and muscle damage. No group differences (p > 0.05) were observed between recovery interventions for all measures, suggesting that the IPC protocol used was not effective in this population. / February 2017

INTRODUÇÃO: O dano muscular induzido pelo exercício (DMIE) em humanos ocorre quando o indivíduo realiza exercícios não-habituais, muito intensos ou de longa duração. Muitos protocolos experimentais têm se dedicado ao estudo do DMIE, porém poucos deles, principalmente aqueles com ações excêntricas, reproduzem uma situação real de treinamento físico. OBJETIVO: O objetivo geral desta pesquisa é verificar e comparar a ocorrência de dano muscular nos flexores do cotovelo induzido pelo sistema de treinamento de cargas descendentes em exercício resistido em duas diferentes intensidades por meio de marcadores indiretos de dano muscular: creatina quinase (CK), mioglobina (Mio), dor e torque muscular. MÉTODO: Foram voluntários 9 indivíduos do gênero masculino com idade média (\'+ OU -\' desvio padrão) de 26,78 \'+ OU -\' 4,32 anos, peso médio 84,02 \'+ OU -\' 13,88 quilos e altura média 181,33 \'+ OU -\' 8,46 centímetros. Os indivíduos realizaram dois protocolos de exercício resistido com ações concêntricas e excêntricas dos flexores do cotovelo nos exercícios rosca Scott e rosca direta com cargas descendentes em diferentes intensidades, uma iniciada em 90% de 1-RM (PROTOCOLO 90%) e outra iniciada em 75% de 1-RM (PROTOCOLO 75%). Os marcadores de dano muscular CK, Mio, dor e torque muscular foram avaliados previamente ao exercício, imediatamente após o exercício, 24, 48, 96 e 168 horas após o exercício. RESULTADOS: O pico de concentração de CK ocorreu 24 horas após a sessão de exercício dos PROTOCOLOS 75% e 90%, sem diferenças significativa entre os valores (p < 0,05). O pico de concentração de Mio ocorreu imediatamente após a sessão de exercício dos PROTOCOLOS 75% e 90%, sem diferenças significativa entre os valores (p < 0,05). O pico de dor ocorreu 24 horas após a sessão de exercício do PROTOCOLO 75% e permaneceu com o mesmo valor 48 horas após, com percepção referente à \"dor um pouco forte\" indicada na escala de Borg e no PROTOCOLO 90% obteve o pico imediatamente após o esforço com percepção referente à \"dor moderada\". A maior diminuição do torque muscular ocorreu imediatamente após a sessão de exercício dos PROTOCOLOS 75% e 90% sem diferenças significativa entre os valores (p < 0,05). CONCLUSÃO: Foi possível sugerir a ocorrência do dano muscular e ambos os protocolos pelas variáveis investigadas. O torque muscular demonstrou ser o melhor marcador do dano muscular por avaliar de forma não-invasiva a funcionalidade e restabelecimento das estruturas do músculo. O PROTOCOLO 90% parece ser mais vantajoso praticamente por demonstrar as mesmas características nas variáveis CK, Mio e torque muscular com menor percepção de dor. Porém, pesquisas com adaptações ao treinamento crônico são necessárias para fortalecer estas afirmações. / INTRODUCTION: Exercise-induced muscle damage (EIMD) in humans occurs after unaccustomed or vigorous exercise. Various experimental models was dedicated to EIMD, however few studies, essential those with eccentric action, replicated action that commonly occur during real physical training. PURPOSE: The general purpose of this research was to verify and to compare changes in indirect markers of muscle damage (Creatine Kinase (CK), myoglobin (Myo), pain and muscle torque) on the elbow flexors following training system of drop set in resistance exercise in two different intensities. METHODS: 9 young men (age: 26,78 \'+ OU -\' 4,32 years, height: 181,33 \'+ OU -\' 8,46 cm, body mass: 84,02 \'+ OU -\' 13,88 Kg) performed two exercise protocols of drop set resistance exercise with actions concentric and eccentric of the elbow flexors in Scott arm curl and direct arm curl of 90% (PROTOCOL 90%) and 75% (PROTOCOL 75%) of one maximal repeated. The indirect markers was obtained before, immediately after, and 24, 48, 96 and 168 hours after exercise. RESULTS: The CK\'s concentration peak occurs 24 hours after exercise in both protocols, without significant differences (p < 0.05). The Myo\'s concentration peak occurs 24 immediately after the exercise in both protocols, without any significant differences (p < 0.05). The pain peak 24 hours after the exercise of PROTOCOL 75% and continued in the same value 48 hours later, with pain perception of \"pain a little strong\", indicated in Borg\'s Scale. In the PROTOCOL 90% obtained a peak immediately after exercise with perception of \"moderate pain\". The greater reduction of the muscle torque occurs immediately after the exercise in both protocols, without any significant difference (p < 0.05). CONCLUSION: It was possible suggest, through of indirect markers, that both protocols induced a muscle damage. The muscle torque shown to be a better marker of muscle damage because is a non-invasive way to evaluate the functionality of muscle structure. The PROTOCOL 90% seem to be more profitable in the practice because of magnitude pain perception.

INTRODUÇÃO: O dano muscular induzido pelo exercício (DMIE) em humanos ocorre quando o indivíduo realiza exercícios não-habituais, muito intensos ou de longa duração. Muitos protocolos experimentais têm se dedicado ao estudo do DMIE, porém poucos deles, principalmente aqueles com ações excêntricas, reproduzem uma situação real de treinamento físico. OBJETIVO: O objetivo geral desta pesquisa é verificar e comparar a ocorrência de dano muscular nos flexores do cotovelo induzido pelo sistema de treinamento de cargas descendentes em exercício resistido em duas diferentes intensidades por meio de marcadores indiretos de dano muscular: creatina quinase (CK), mioglobina (Mio), dor e torque muscular. MÉTODO: Foram voluntários 9 indivíduos do gênero masculino com idade média (\'+ OU -\' desvio padrão) de 26,78 \'+ OU -\' 4,32 anos, peso médio 84,02 \'+ OU -\' 13,88 quilos e altura média 181,33 \'+ OU -\' 8,46 centímetros. Os indivíduos realizaram dois protocolos de exercício resistido com ações concêntricas e excêntricas dos flexores do cotovelo nos exercícios rosca Scott e rosca direta com cargas descendentes em diferentes intensidades, uma iniciada em 90% de 1-RM (PROTOCOLO 90%) e outra iniciada em 75% de 1-RM (PROTOCOLO 75%). Os marcadores de dano muscular CK, Mio, dor e torque muscular foram avaliados previamente ao exercício, imediatamente após o exercício, 24, 48, 96 e 168 horas após o exercício. RESULTADOS: O pico de concentração de CK ocorreu 24 horas após a sessão de exercício dos PROTOCOLOS 75% e 90%, sem diferenças significativa entre os valores (p < 0,05). O pico de concentração de Mio ocorreu imediatamente após a sessão de exercício dos PROTOCOLOS 75% e 90%, sem diferenças significativa entre os valores (p < 0,05). O pico de dor ocorreu 24 horas após a sessão de exercício do PROTOCOLO 75% e permaneceu com o mesmo valor 48 horas após, com percepção referente à \"dor um pouco forte\" indicada na escala de Borg e no PROTOCOLO 90% obteve o pico imediatamente após o esforço com percepção referente à \"dor moderada\". A maior diminuição do torque muscular ocorreu imediatamente após a sessão de exercício dos PROTOCOLOS 75% e 90% sem diferenças significativa entre os valores (p < 0,05). CONCLUSÃO: Foi possível sugerir a ocorrência do dano muscular e ambos os protocolos pelas variáveis investigadas. O torque muscular demonstrou ser o melhor marcador do dano muscular por avaliar de forma não-invasiva a funcionalidade e restabelecimento das estruturas do músculo. O PROTOCOLO 90% parece ser mais vantajoso praticamente por demonstrar as mesmas características nas variáveis CK, Mio e torque muscular com menor percepção de dor. Porém, pesquisas com adaptações ao treinamento crônico são necessárias para fortalecer estas afirmações. / INTRODUCTION: Exercise-induced muscle damage (EIMD) in humans occurs after unaccustomed or vigorous exercise. Various experimental models was dedicated to EIMD, however few studies, essential those with eccentric action, replicated action that commonly occur during real physical training. PURPOSE: The general purpose of this research was to verify and to compare changes in indirect markers of muscle damage (Creatine Kinase (CK), myoglobin (Myo), pain and muscle torque) on the elbow flexors following training system of drop set in resistance exercise in two different intensities. METHODS: 9 young men (age: 26,78 \'+ OU -\' 4,32 years, height: 181,33 \'+ OU -\' 8,46 cm, body mass: 84,02 \'+ OU -\' 13,88 Kg) performed two exercise protocols of drop set resistance exercise with actions concentric and eccentric of the elbow flexors in Scott arm curl and direct arm curl of 90% (PROTOCOL 90%) and 75% (PROTOCOL 75%) of one maximal repeated. The indirect markers was obtained before, immediately after, and 24, 48, 96 and 168 hours after exercise. RESULTS: The CK\'s concentration peak occurs 24 hours after exercise in both protocols, without significant differences (p < 0.05). The Myo\'s concentration peak occurs 24 immediately after the exercise in both protocols, without any significant differences (p < 0.05). The pain peak 24 hours after the exercise of PROTOCOL 75% and continued in the same value 48 hours later, with pain perception of \"pain a little strong\", indicated in Borg\'s Scale. In the PROTOCOL 90% obtained a peak immediately after exercise with perception of \"moderate pain\". The greater reduction of the muscle torque occurs immediately after the exercise in both protocols, without any significant difference (p < 0.05). CONCLUSION: It was possible suggest, through of indirect markers, that both protocols induced a muscle damage. The muscle torque shown to be a better marker of muscle damage because is a non-invasive way to evaluate the functionality of muscle structure. The PROTOCOL 90% seem to be more profitable in the practice because of magnitude pain perception.

Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The aim of the study was to investigate skeletal muscle changes induced by an acute bout of plyometric exercise before and after plyometric training. The study consisted of an acute study and training intervention study. The acute study, investigated whether direct evidence of ultrastructural damage and identification of indirect factors were more evident in subjects presenting with rhabdomyolysis. Moreover the training intervention study investigated whether plyometric training would protect the muscle from ultrastructural damage and rhabdomyolysis. During the acute intervention, twenty six healthy untrained individuals completed an acute bout of plyometric exercise (10 x 10 squat-jumps, 1 min rest). After, thirteen subjects continued with the training intervention. Eight of these subjects completed 8 weeks of plyometric jump training, while five subjects were instructed to rest from physical activity for 8 weeks. Seven days after the final training session the training and rest group repeated a second acute bout of plyometric exercise. Acute Study: Creatine kinase (CK) activity increased significantly following the single bout of plyometric exercise in all subjects (baseline: 129 to day 4: 5348 U/l). This was accompanied by an increase in perceived pain, C-reactive protein (CRP) a marker of inflammation as well as white blood cells (WBCs). Electron micrographs of muscle biopsies taken 3 days post exercise showed evidence of ultrasructural damage and membrane damage was apparent by immunofluorescence by the loss of dystrophin staining. A stretch of the c-terminus of titin was observed by immunogold, and western blot analysis indicated an increase in calpain-3 autolysis. Based on individual CK responses (CK range: 153-71,024 U/L at 4days after exercise) the twenty six subjects were divided into two groups, namely the high (n=10) and low responders (n=16). Training intervention: Following training the trained group did not experience: a rise of CK activity (110.0 U/l), perceived pain, CRP, WBCs, Z-line streaming, a stretch of titin or calpain-3 activation; while in the control group only two subjects presented with Z-line streaming. The results indicate that high responders have a more pronounced inflammatory response compared to low responders after eccentric exercise, therefore more WBCs and more specifically neutrophils are recruited to damaged areas resulting in greater membrane damage by respiratory burst in high responders. This damage can be limited with training by remodelling sarcomeric proteins via calpain activation resulting in the stable assembly of proteins in the sarcomere preventing the release of proteins. / AFRIKAANSE OPSOMMING: Die doel van die studie was om skeletspier veranderinge wat teweeggebring is deur voor en na afloop van akute pleometriese oefening, te ondersoek. Die studie bestaan uit ‘n akute intervensie en ‘n oefeningsintervensie gedeelte. Die akute intervensie het ondersoek ingestel na die direkte bewyse van ultrastrukturele skade en identifikasie van indirekte faktore meer sigbaar is in proefpersone wat met rhabdomiolose presenteer. Meerso het die oefningsintervensie die moontlikheid dat pleometriese oefening die spier van ultrastrukturele skade en rhabdomiolose beskerm, ondersoek. Tydens die akute intervensie is 26 gesonde ongeoefende individue die akute pleometriese oefeningsessie (10 x 10 hurkspronge, 1 min rus) voltooi. Hierna het 13 proefpersone voortgegaan met die oefeningsintervensie. Agt van hierdie proefpersone het agt weke pleometriese sprongsessie oefeninge voltooi, terwyl vyf proefpersone gevra is om vir 8 weke geen oefeninge te doen nie. Sewe dae na afloop van die finale oefeningssessie het die oefening en kontrole groep in ‘n tweede herhaalde akute pleometriese oefeningsessie deelgeneem. Akute intervensie: kreatienkinase (KK) aktiwiteit het betekenisvol verhoog na die enkel pleometriese oefeningsessie in all proefpersone (basislyn: 129 tot op dag vier: 5348 U/l). Hierdie is vergesel met ‘n toename in die persepsie van pyn, c-reaktiewe proteïen (CRP) ‘n merker van inflammasie sowel as witbloedselle (WBS). Elektronmikrograwe van spierbiopsies wat geneem is drie dae na afloop van die oefeninge, het tekens van ultrastrukturele skade en membraanskade getoon wat ook deur immunofluoresensie duidelik warneembaar was deur die verlies van distrofienverkleuring. ‘n Verrekking van die c-terminus van titin is ook waargeneem deur middel van immunogold. Westernblot analyse het ‘n toename in calpain-3 outolise getoon. Gegrond op individuele KK response (KK grense: 153-71,024 U/L na vier dae post oefening) is 26 proefpersone verdeel in twee groepe naamlik ‘n hoë (n=10) en lae responders (n=16). Oefeningintervensie:: Na oefening het die geoefende groep nie ‘n toename in KK aktiwiteit getoon nie (KK aktiwiteit (110.0 U/l)), pynervaring, CRP, WBS, Z-lynstroming, ‘n strekking van titin of calpain-3 aktivering; terwyl in die kontrole groep daar slegs twee proefpersone met Z-lynstroming geïdentifiseer is. Die resultate wyse daarop dat hoë responders ‘n meer uitgesproke inflammatoriese reaksie toon vergeleke met die lae responders na afloop van essentriese oefening. Daar word dus meer WBS en spesifiek meer neutrofiele na beskadigde areas gelokaliseer wat in grootter membraanskade deur respiratoriese inspanning in die hoë responders. Hierdie skade kan beperk word deur oefening waardeur hermodulering van sarkomeriese proteïene via calpain aktivering tot stabiele rangskiking van proteïene in die sarcomere lei en daardeur proteïen vrystelling verhinder. / The NRF for financial assistance

It is well documented that engaging in resistance exercise can lead to further improvements in endurance performance. Whilst, not fully understood, it is speculated that increased motor unit recruitment, improved muscle coordination and enhanced utilisation of stored elastic energy after resistance-based exercise improves exercise economy. Nevertheless, while prolonged exposure to resistance training improves endurance performance in the long-term, a consequence of such training when unaccustomed is the appearance of exercise-induced muscle damage (EIMD). Exercise-induced muscle damage is well known to affect athletic performance requiring muscular strength and power; however, its effects on markers of endurance exercise are unclear. Therefore, the aim of this thesis was to investigate the effects of EIMD on endurance performance, with an emphasis on the physiological (oxygen uptake; , minute ventilation; ), metabolic (blood lactate; [La]), perceptual (rating of perceived exertion; RPE) and kinematic (stride length; SL, stride frequency; SF) responses during sub-maximal endurance exercise.

A realização de uma sessão com ações excêntricas provoca dano na estrutura muscular. Durante o processo de recuperação, essa estrutura sofre adaptações que a protegem da ocorrência de dano nas sessões subseqüentes. Essas adaptações são chamadas de Efeito da Carga Repetida (ECR). Esse efeito foi estudado com a realização de apenas duas sessões de exercícios. A velocidade da ação excêntrica também pode contribuir para a variabilidade do dano induzido. O objetivo desse estudo foi investigar através da análise dos indicadores indiretos, creatina quinase (CK), força, dor, circunferência e amplitude de movimento (ADM), o dano induzido por diferentes velocidades da ação excêntrica e o efeito da carga repetida com a realização das diferentes velocidades (60ºs-1 (Exc60) e 180ºs-1 (Exc180)); e verificar se o efeito da carga repetida seria maior com a realização de três sessões de exercícios. Os resultados dos indicadores analisados tiveram alterações semelhantes nos grupos Exc60 e Exc180, sugerindo que as diferentes velocidades parecem não interferir na magnitude do dano induzido. O ECR não foi diferente entre as velocidades, pois o comportamento das variáveis analisadas foi semelhante entre os dois grupos nas duas sessões iniciais. A realização da terceira sessão de exercícios excêntricos não promove o aumento do efeito protetor, visto que não houve diferenças significantes entre a segunda e a terceira sessão. Indicando que o ECR advém principalmente da realização da primeira sessão / Performing a bout of eccentric exercise causes muscle damage. During recovery, some adaptations occur that can protect muscle structure. These adaptations are known as Repeated Bout Effect. However, this phenomenon has been studied with two bouts. Velocity of eccentric action has been referred as one possible factor which can affect the extension of muscle damage. The aim of this study was to investigate muscle damage induced by different velocities, the repeated bout effect with different velocities and to verify if the repeated bout effect could be larger if three bouts of eccentric exercise were performed. Results of indirect markers of muscle damage (CK, DOR, upper-arm circumference, maximal isometric force) showed similar alterations in groups Exc60 and Exc180, suggesting that different velocities do not affect the extension of muscle damage. Repeated bout effect is not different between velocities, because changes in markers were comparable in both groups after the first two bouts. After performing a third bout of eccentric exercise, there was not any significant differences between second and third bouts. It indicates that the first bout is responsible for the adaptations of the repeated bout effect

O dano muscular induzido pelo exercício (DMIE) e os diferentes elementos envolvidos em seu processo têm sido amplamente estudados. A doença periodontal (DP), por sua vez, tem sido indicada como um possível fator de risco para várias condições sistêmicas, como diabetes, doenças cardiovasculares, partos prematuros, obesidade, entre outros. Tais associações têm sido atribuídas à possibilidade de que a DP possa induzir um processo de inflamação sistêmica de baixa intensidade, caracterizado pela elevação de biomarcadores sanguíneos que também estão envolvidos no mecanismo de dano muscular induzido pelo exercício (DMIE). O objetivo do presente estudo é investigar se a doença periodontal pode atuar como um modificador do DMIE em homens saudáveis. Foram avaliados 40 indivíduos, com idade entre 25 e 45 anos, que buscaram atendimento na faculdade de odontologia da UFRGS ou eram praticantes de atividades físicas. Questionário estruturado para obtenção de dados demográficos e comportamentais e o IPAQ (International Physical Activity Questionnaire) foram aplicados. Dois periodontistas examinaram perda de inserção (PI), profundidade de sondagem, sangramento à sondagem e índices de placa e sangramento gengival no exame basal, juntamente com avaliações antropométricas. Os participantes então realizaram um protocolo de indução de dano muscular que incluiu cinco séries de 15 contrações excêntricas máximas dos quadríceps de uma perna, em um dinamômetro isocinético. Força muscular (contrações isométricas voluntárias máximas - CIVM), espessura e ecogenicidade muscular (ultrassonografia) e dor (escala visual analógica) foram avaliadas em diferentes momentos em relação ao protocolo. Modelos de regressão logística multivariados foram ajustados para idade, educação, índice de massa corporal, fumo, consumo de álcool, proteína C reativa e nível de atividade física. Nessa amostra, PI esteve associada a maiores reduções de força muscular após o protocolo, com um aumento de 1 mm na média de PI representando 7% a mais de redução na CIVM. Pode-se concluir, a partir dessa análise preliminar, que a doença periodontal pode ser considerada um modificador do processo de dano muscular, aumentando a deterioração da força muscular. / Exercise-induced muscle damage (EIMD) and the different elements involved in it´s process has been largely studied. Periodontal diseases (PD) has been pointed out as a possible risk fator for a number of systemic conditions, like diabetes, cardiovascular diseases, preterm birth, obesity, and others. Such associations has been atribbuted to the fact that PD can lead to a low-grade inflammatory process, characterized by elevated blood concentrations of biomarkers that are also involved in the EIMD mechanisms. The aim of this study is to assess whether PD can act as a EIMD modifier in healthy men. This study included 40 healthy males with 25-45 yrs that seek for treatment at Dentistry Faculty or are physical activiy practitioners. A structured questionnaire to obtain demographic and comportamental data and the IPAQ (International Physical Activity Questionnaire) were applied. Two periodontists assessed attachment loss (AL), probing depth (PD), bleeding on probing (BOP), plaque and bleeding index in the baseline exam, together with anthropometrical evaluation. The participants then performed a muscle damage protocol comprising five sets of 15 maximum eccentric contractions of the quadriceps muscles of one leg in a isokinetic dynamometer. Evaluations of muscle strength (maximal voluntary isometric contraction), muscle thickness and echo intensity (ultrasonography images) and soreness (visual analogue scale) were made at different periods in relation to the protocol. Multivariable logistic models were fitted adjusting for age, education, body mass index (BMI), smoking, alcohol consumption, C-reactive protein (CRP) and physical activiy level. In this sample, AL was associated with higher reductions of muscle force, with a 1- mm increment in AL mean significantly decreased CIVM by 7%. It can be concuded, based on this preliminar analysis, that PD may be considered as a modifier of EIMD, increasing muscle strenght deterioration.