Respostas metabólicas nos limiares de lactato e anaeróbio, na musculatura esquelética dos membros inferiores de idosas, no teste de Bruce modificado
Data
2005
Autores
Alabarse, Silvio Lopes 
Orientadores
Ramos, Luiz Roberto
Ramos, Luiz Roberto
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Introdução: Atualmente encontramos uma emergente procura de idosas
acima de 60 anos de idade pela prática de exercícios físicos. Existe uma
grande preocupação dos profissionais da área de saúde em diagnosticar
primeiramente a condição física de iniciantes ou já praticantes de atividades
físicas, nesta faixa etária, através de um teste ergométrico usado em larga
escala, denominado protocolo modificado de Bruce, tendo, em geral, como
objetivo, analisar as respostas cardíacas do envolvido, principalmente as
eletrocardiográficas, não relatando o comportamento metabólico devido ao
estímulo sugerido no teste. Como descrito na literatura, indivíduos jovens, não
sedentários, no final de um teste de esforço, apresentam, em geral, o limiar de
lactato (LLac 3,5mMol) e respectiva fadiga muscular, após atingirem o limiar
anaeróbio I. No entanto, em idosas, deste estudo, suspeitamos que este
comportamento não seria o mesmo, também atingiriam o limiar anaeróbio I,
porém, na finalização do teste, apresentariam o limiar de lactato com valores
inferiores (LLac 2mMol) em relação a indivíduos com menos idade,
representado uma fadiga muscular (periférica) precoce em relação a sujeitos
jovens. Objetivo: analisar as respostas metabólicas nos limiares de lactato e
anaeróbio, na musculatura esquelética dos membros inferiores de idosas, no
teste de Bruce modificado. Material e Métodos: Analisamos 16 indivíduos do
sexo feminino, com idade média de 69±6 anos através de um teste
ergométrico tipo rampa, protocolo modificado de Bruce, em esteira rolante
elétrica, com um analisador de trocas gasosas e um lactímetro. Avaliou-se a
resposta do lactato sangüíneo, procurando identificar se os sujeitos estavam
acima do limiar de lactato fixo de 2mMols ao final do teste em exaustão física,
após atingirem o limiar anaeróbio I, representando uma fadiga central e
periférica concomitante. Resultados: Os sujeitos envolvidos apresentaram
valores de lactato superiores ao limiar de lactato fixo de 2mMols, após
estarem acima do limiar anaeróbio I, ao atingirem o maior desempenho físico
no protocolo modificado de Bruce. Conclusão: Ao contrário de sujeitos
jovens, que apresentam, em geral, fadiga muscular no final de um teste de
esforço com valores elevados de lactato sanguíneo, idosas do grupo
investigado, como nós esperávamos, demonstraram fadiga na musculatura,
com índices menores de lactato, quando ultrapassado o limiar anaeróbio I e o
limiar de lactato fixo de 2mMols (p≤0,001), indicando, assim, a ocorrência de
fadiga simultânea da musculatura esquelética dos membros inferiores e da
capacidade de troca respiratória, devido à acidose metabólica.
Introduction: Recently there has been a substantial increase of elderly women over 60 years old looking for exercise practice, aiming therapeutical or recreational proposes. There is a great concern of health professionals to diagnose the physical condition of beginners and those who are already practitioners of physical activities in this age group, through a largely applied ergometric test, the Modified Bruce Protocol, which aims to analyze cardiac responses of the individual, mainly through the electrocadiographical aspects, without quoting the metabolic behavior related to the stimulus suggested in the test. As described in literature, non-sedentary young subjects, at the end of an effort test, usually present the lactate threshold (TrLac 3.5 mMol) and muscle fatigue after achieving the anaerobic threshold I. Nevertheless, in the group of edelry women assessed in this study, it was presumpted that this behavior would not be the same: they would also achieve the anaerobic threshold I, but at the end of the test they would present a lower values of lactate threshold (TrLac 2 mMol) compared to younger subjects, demonstrating that the periferic muscle fatigue, occurs more precociously than in younger subjects. Objective: Analyze the metabolic responses of the lactate and anaerobic threshold of lower limb’s skeletal muscles of ederly women, assessed through the Modified Bruce Protocol. Materials and Methods: 16 women with median age of 69 years old were assessed through the ramp ergometric test, designated as the Modified Bruce Protocol, in a treadmill with a device which analyzes gas exchanges and also a lactate analyzer. The subjects’ metabolic response to blood lactate was analyzed in order to identify if the lactate threshold was higher than the settled value of 2mMols by the end of the test, when the individuals were in physical exhaustion, after achieving anaerobic threshold I, which represents a simultaneous central and peripheral fatigue. Results: The individuals involved in this study reached blood lactate rates higher than the settled value of 2m/Mols after exceeding the anaerobic threshold I and achieving the highest physical performance in the Modified Bruce Protocol. Conclusion: In contrast to young adults, that mainly achieve muscle fatigue at the end of an effort test with high blood lactate rates, the group of edelry women assessed in this research, as expected, had muscle’s fatigue and presented lower lactate rates, when the anaerobic threshold I and the settled lactate threshold of 2mMols (p≤0.001) was exceeded, thus denoting fatigue both in skeletal muscles of lower limbs as well as of the respiratory exchange due to metabolic acidosis.
Introduction: Recently there has been a substantial increase of elderly women over 60 years old looking for exercise practice, aiming therapeutical or recreational proposes. There is a great concern of health professionals to diagnose the physical condition of beginners and those who are already practitioners of physical activities in this age group, through a largely applied ergometric test, the Modified Bruce Protocol, which aims to analyze cardiac responses of the individual, mainly through the electrocadiographical aspects, without quoting the metabolic behavior related to the stimulus suggested in the test. As described in literature, non-sedentary young subjects, at the end of an effort test, usually present the lactate threshold (TrLac 3.5 mMol) and muscle fatigue after achieving the anaerobic threshold I. Nevertheless, in the group of edelry women assessed in this study, it was presumpted that this behavior would not be the same: they would also achieve the anaerobic threshold I, but at the end of the test they would present a lower values of lactate threshold (TrLac 2 mMol) compared to younger subjects, demonstrating that the periferic muscle fatigue, occurs more precociously than in younger subjects. Objective: Analyze the metabolic responses of the lactate and anaerobic threshold of lower limb’s skeletal muscles of ederly women, assessed through the Modified Bruce Protocol. Materials and Methods: 16 women with median age of 69 years old were assessed through the ramp ergometric test, designated as the Modified Bruce Protocol, in a treadmill with a device which analyzes gas exchanges and also a lactate analyzer. The subjects’ metabolic response to blood lactate was analyzed in order to identify if the lactate threshold was higher than the settled value of 2mMols by the end of the test, when the individuals were in physical exhaustion, after achieving anaerobic threshold I, which represents a simultaneous central and peripheral fatigue. Results: The individuals involved in this study reached blood lactate rates higher than the settled value of 2m/Mols after exceeding the anaerobic threshold I and achieving the highest physical performance in the Modified Bruce Protocol. Conclusion: In contrast to young adults, that mainly achieve muscle fatigue at the end of an effort test with high blood lactate rates, the group of edelry women assessed in this research, as expected, had muscle’s fatigue and presented lower lactate rates, when the anaerobic threshold I and the settled lactate threshold of 2mMols (p≤0.001) was exceeded, thus denoting fatigue both in skeletal muscles of lower limbs as well as of the respiratory exchange due to metabolic acidosis.
Descrição
Citação
ALABARSE, Silvio Lopes. Respostas metabólicas nos limiares de lactato e anaeróbio, na musculatura esquelética dos membros inferiores de idosas, no teste de Bruce modificado. 2005. 131 f. Dissertação (Mestrado em Ciências) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2005.