Comparação da força e resistência dos músculos inspiratórios entre ativos e sedentários / Comparison of the strength and resistance of inspirational muscles between assets and sedentary

Introdução: A prática regular de atividade física está associada com melhora do estado de saúde, aumento da capacidade funcional, aumento da força muscular e redução da mortalidade por doenças cardíacas. Apesar dos benefícios de a prática regular de exercício físico estarem consolidados na literatura, as adaptações na força e resistência dos músculos inspiratórios são controversas. Objetivo: Testar a hipótese que não há diferença da força e resistência dos músculos inspiratórios entre indivíduos ativos e sedentários. Métodos:Estudo observacional de corte transversal. Avaliou-se indivíduos entre 18 e 30 anos, ambos os sexos e saudáveis. Os voluntários foram divididos em ativos e sedentários de acordo a classificação da American College of Sports Medicine (ACMS). Os indivíduos tiveram a força máxima dos músculos inspiratórios (FMI) determinada através do dispositivo POWERbreathe® K5 inspiratory muscle trainer, que intula esta variável como Sindex. A resistência dos músculos inspiratórios foi avaliada través de um teste incremental. Para comparação das médias foi aplicada o teste t de student para distribuição simétrica, p< 0,05. O estudo foi aprovado pelo comitê de ética em pesquisa com CAAE : 37781014.4.0000.5544. Resultados: Foram avaliados 92 indivíduos, destes 55 (60%) foram classificados como ativos e 57 (62%) do sexo masculino. Ao realizar a comparação do Sindex entre ativos e sedentários (128±26; 119±24 cmH2O; p=0,85) e da exaustão no teste incremental (6516% e 6016%;p=0,095), respctivamente. Conclusão: Os indivíduos ativos não apresentam músculos inspiratórios mais fortes e resistentes quando comparados com sedentários. [AU]

Introduction: The regular practice of physical activity is associated with improved health status, increased functional capacity, increased muscle strength and reduced mortality from heart disease. Although the benefits of regular exercise are well established in the literature, adaptations in inspiratory muscle strength and endurance are controversial. Objective: To test the hypothesis that there is no difference in the strength and resistance of the inspiratory muscles between active and sedentary individuals. Methods: Cross-sectional observational study. It was evaluated individuals between 18 and 30 years old, both sexes and healthy. The volunteers were divided into active and sedentary according to the classification of the American College of Sports Medicine (ACMS). Individuals had maximal inspiratory muscle strength (IMS) determined through the POWERbreathe® K5 inspiratory muscle trainer, which injects this variable as Sindex. The inspiratory muscle strength was evaluated through an incremental test. For the comparison of the means the student's t-test was applied for symmetrical distribution, p <0.05. The study was approved by the research ethics committee with CAAE: 37781014.4.0000.5544. Results: A total of 92 individuals were evaluated. Of these, 55 (60%) were classified as active and 57 (62%) were male. When comparing Sindex between active and sedentary (128 ± 26/119 ± 24 cmH2O, p = 0.85) and exhaustion in the incremental test (63.2 ± 16.1%. p = 0.095), respectively. Conclusion: Active individuals do not present stronger and stronger inspiratory muscles when compared to sedentary ones. [AU]

Bases fisiopatológicas del entrenamiento muscular en pacientes con enfermedad pulmonar obstructiva crónica / Pathophysiological bases of muscular training in patients with chronic obstructive pulmonary disease

Dyspnea and decreased exercise capacity are the main factors that limit the daily living activities in patients with chronic respiratory diseases. The cardinal symptoms limiting exercise capacity in most patients with chronic obstructive pulmonary disease (COPD) are dyspnea and fatigue, which could be caused by alveolar ventilation and gas exchange disturbances, skeletal muscle dysfunction and/or cardiovascular failure. Anxiety, lack of motivation and depression were also associated with reduced exercise capacity, probably affecting the perception of symptoms. The relationship between psychological status and mood disorders in patients with COPD and exercise tolerance is complex and not yet fully understood. The origin of the exercise capacity limitation in COPD patients is multifactorial, so the separation of the variables involved for academic purposes is not always feasible. The pathogenic mechanisms may interact in complex ways, as an example, muscle deconditioning and hypoxemia can increase alveolar ventilation causing exercise limitation. Therefore, physical training and supplemental oxygen can reduce ventilatory limitation during exercise without changing lung function and maximum ventilatory capacity. The analysis of these factors could potentially identify reversible conditions that can improve the exercise performance and quality of life ofpatients with COPD, such as hypoxemia, bronchospasm, heart failure, arrhythmias, musculoskeletal dysfunction and myocardial ischemia. This review examines the principal mechanisms contributing to physical activity limitation in patients with COPD: alveolar ventilation and gas exchange abnormalities, cardiovascular and musculoskeletal system dysfunction, and respiratory muscles dysfunction.

La disnea y la disminución de la capacidad de realizar ejercicio son los principales factores que limitan las actividades de la vida diaria en pacientes con enfermedades respiratorias crónicas. Los síntomas cardinales que limitan la capacidad de ejercicio en la mayoría de los pacientes con enfermedad pulmonar obstructiva crónica (EPOC) son la disnea y/o fatigabilidad, los cuales pueden ser ocasionados por trastornos de la ventilación alveolar e intercambio gaseoso, disfunción de los músculos esqueléticos y/o falla cardiovascular. La ansiedad, falta de motivación y depresión también han sido asociadas a una menor capacidad de realizar ejercicio, probablemente afectando la percepción de los síntomas. La relación entre el estado psicológico y los trastornos del ánimo en pacientes con EPOC y la tolerancia al ejercicio es compleja y aún no ha sido completamente dilucidada. El origen de la limitación de la capacidad de ejercicio en pacientes con EPOC es multifactorial, por lo cual la separación de las variables involucradas con fines académicos no siempre es factible realizarlo en los pacientes. Los mecanismos patogénicos pueden relacionarse en forma compleja, a modo de ejemplo, el desacondicionamiento físico y la hipoxemia pueden contribuir a aumentar la ventilación alveolar ocasionando limitación del ejercicio de causa ventilatoria. Por lo tanto, el entrenamiento físico y el suplemento de oxígeno pueden reducir la limitación ventilatoria durante el ejercicio sin modificar la función pulmonar o la capacidad ventilatoria máxima. El análisis de los factores limitantes de la capacidad de ejercicio permite identificar trastornos potencialmente reversibles que pueden mejorar la calidad de vida de los enfermos, tales como la hipoxemia, broncoespasmo, insuficiencia cardiaca, arritmias, disfunción musculoesquelética y/o isquemia miocárdica. En esta revisión se examinan los principales mecanismos que contribuyen a la limitación de la actividad física en pacientes con EPOC:...

Entrenamiento muscular inspiratorio en el paciente con enfermedad pulmonar obstructiva crónica / Inspiratory muscle training in patients with chronic obstructive pulmonary disease

Respiratory muscle weakness is observed in chronic obstructive pulmonary disease (COPD) patients and contributes to hypoxemia, hypercapnia, dyspnoea, nocturnal oxygen desaturation and reduced exercise performance. During exercise it has been shown that diaphragm work is increased in COPD and COPD patients use a larger proportion of the maximal inspiratory pressure (PImax) than healthy subjects. This pattern of breathing is closely related to the dyspnoea sensation during exercise and might potentially induce respiratory muscle fatigue. However, diaphragmatic fatigue was not demonstrated after exhaustive exercise. Studies in patients with COPD have shown natural adaptations of the diaphragm to greater oxidative capacity and resistance to fatigue. The above mentioned considerations gave conflicting arguments to the rationale of inspiratory muscle training (IMT) in COPD. Both IMT alone and IMT as adjunct to general exercise reconditioning significantly increased inspiratory muscle strength and endurance. A significant effect was found for dyspnoea at rest and during exercise. Improvedfunctional exercise capacity tended to be an additional effect of IMT alone and as an adjunct to general exercise reconditioning, but this trend did not reach statistical significance. No significant correlations were found for training effects with patient characteristics. However, subgroup analysis in IMTplus exercise training revealed that patients with inspiratory muscle weakness improved significantly more compared to patients without inspiratory muscle weakness. From this review it is concluded that inspiratory muscle training is an important addition to a pulmonary rehabilitation programme directed at chronic obstructive pulmonary disease patients with inspiratory muscle weakness. The effect on exercise performance is still to be determined. In summary, IMT improves inspiratory muscle strength and endurance, functional exercise capacity, dyspnoea and quality of life. Inspirat...

Los pacientes con enfermedad pulmonar obstructiva crónica (EPOC) tienen debilidad de los músculos respiratorios, lo cual contribuye a la disnea, hipoxemia, hipercapnia, desaturación nocturna y limitación de la actividad física. Durante el ejercicio se ha demostrado que aumenta el trabajo del diafragma en pacientes con EPOC y utilizan una mayor proporción de la presión inspiratoria máxima (PImax) comparado con los sujetos sanos. Elpatrón respiratorio anormal de los pacientes con EPOC está relacionado con la sensación de disnea durante el ejercicio y, potencialmente, podría inducir a la fatiga muscular respiratoria. Sin embargo, la fatiga del diafragma no se ha demostrado después de un ejercicio intenso. Los estudios en pacientes con EPOC han demostrado cambios adaptativos en las fibras musculares del diafragma que tienen mayor capacidad oxidativa y resistencia a la fatiga. De este modo, existen argumentos contradictorios en relación al beneficio clínico obtenido con el entrenamiento de los músculos inspiratorios (EMI) en pacientes con EPOC. El EMI aislado o como complemento de ejercicios de reacondicionamiento general aumenta significativamente la fuerza muscular inspiratoria y la resistencia a la fatiga, disminuyendo significativamente la disnea en reposo y durante el ejercicio. Además, los estudios sugieren que el EMI tiende a mejorar la capacidad funcional para realizar ejercicio, efecto favorable que no alcanzó significación estadística. El análisis de subgrupos ha demostrado mayor beneficio clínico del EMI en los pacientes con debilidad muscular inspiratoria. De esta revisión se concluye que el entrenamiento muscular inspiratorio puede ser útil en pacientes seleccionados con enfermedad pulmonar obstructiva crónica, que tienen disfunción muscular inspiratoria comprobada, insertado en un programa de rehabilitación integral. El efecto sobre la capacidad de realizar ejercicio aún no ha sido determinado. En resumen, el EMI aumenta la fuerza muscular inspirator...