There is growing interest in resistance training, but many aspects related to this type of exercise are still not fully understood. Performance varies substantially depending on how resistance training variables are manipulated. Fatigue is a complex phenomenon usually attributed to central (neuronal) and/or peripheral (muscular) origin. Cerebral oxygenation may be associated with the decision to stop exercise, and muscle oxygenation may be related to resistance training responses. Near infrared spectroscopy (NIRS) is a non-invasive optical technique used to monitor cerebral and muscle oxygenation levels. The purpose of this review is to briefly describe the NIRS technique, validation and reliability, and its application in resistance exercise. NIRS-measured oxygenation in cerebral tissue has been validated against magnetic resonance imaging during motor tasks. In muscle tissue, NIRS-measured oxygenation was shown to be highly related to venous oxygen saturation and muscle oxidative rate was closely related to phosphocreatine resynthesis, measured by (31)P-magnetic resonance spectroscopy after exercise. The test-retest reliability of cerebral and muscle NIRS measurements have been established under a variety of experimental conditions, including static and dynamic exercise. Although NIRS has been used extensively to evaluate muscle oxygenation levels during aerobic exercise, only four studies have used this technique to examine these changes during typical resistance training exercises. Muscle oxygenation was influenced by different resistance exercise protocols depending on the load or duration of exercise, the number of sets and the muscle being monitored. NIRS is a promising, non-invasive technique that can be used to evaluate cerebral and muscle oxygenation levels simultaneously during exercise, thereby improving our understanding of the mechanisms influencing performance and fatigue.

A confiabilidade intra-avaliadores é fundamental na determinação da qualidade dos dados coletados em uma pesquisa. Poucos estudos controlados têm reportado valores de confiabilidade de testes de força e, apesar de esta ser considerada boa na maioria dos estudos publicados (0,79 a 0,99), as diferenças entre teste e reteste têm sido observadas como estatisticamente significativas. Dessa forma, sugere-se a utilização dos valores de um segundo teste, pelo menos, em estudos de pesquisa, de modo que eventuais modificações nos valores de força possam ser atribuídas ao efeito dos tratamentos realizados e não à simples adaptação ao protocolo de teste. As relações entre testes de força máxima e testes submáximos ou variáveis antropométricas têm sido investigadas com o intuito de predizer a força máxima sem que o indivíduo tenha que ser submetido a um teste de carga máxima, evitando possíveis riscos de lesão. Valores de carga máxima, ou percentuais desta, são comumente utilizados para melhor prescrever o treinamento. A predição de uma repetição máxima (1RM) através de testes submáximos parece boa (em geral, correlações > 0,90); entretanto, na maioria dos estudos revisados, as equações preditivas desenvolvidas quase sempre não são aprovadas no escrutínio de uma validação cruzada. Assim sendo, especial atenção deve ser dispensada à especificidade da população, do exercício e da técnica de execução, quando do desenvolvimento e aplicação dessas equações. Variáveis antropométricas não foram confirmadas como boas preditoras de 1RM. O número de repetições para dado % de 1RM é diferente para diferentes exercícios, como também o é a carga para determinado número de repetições máximas (nRM), quando executadas em diferentes velocidades. A prescrição do exercício baseada, indiferentemente, em número de repetições ou % de 1RM deve ser considerada com cautela.

objective: Describe clinical characteristics of patients (P) admitted to hospital with suspected acute coronary syndrome (ACS), identifying medical treatment and in-hospital mortality.Methods: Evaluated were 860 patients with ACS from January through December, 2003. We evaluated baseline characteristics, ACS mode of presentation, medication during hospital stay, indication for clinical treatment or myocardial revascularization (MR) and in-hospital mortality.Results: Five hundred and three (58.3%) were male, mean age 62.6 years (± 11.9). Seventy-eight (9.1%) were discharged with the diagnosis of acute ST-elevation myocardial infarction (STEMI), 238 (27.7%) with non-ST-elevation myocardial infarction (non-STEMI), 516 (60%) with unstable angina (UA), two (0.2%) with atypical manifestations of ACS and 26 (3%) with noncardiac chest pain. During hospitalization, 87.9% of patients were given a beta-blocker, 95.9% acetylsalicylic acid, 89.9% anti-thrombin therapy, 86.2% intravenous nitroglycerin, 6.4% glycoprotein (GP) IIb/IIIa receptor inhibitor, 35.9% clopidogrel, 77.9% angiotensin-converting enzyme inhibitor, and 70,9% statin drugs. Coronary arteriography was performed in 72 patients (92.3%) with STEMI, and in 452 (59.8%) with non-STEMI ACS (p< 0.0001). Myocardial revascularization (MR) surgery was indicated for 12.9% and percutaneous coronary intervention for 26.6%. In-hospital mortality was 4.8%, and no difference was recorded between the proportion of deaths among patients with STEMI and non-STEMI ACS (6.4% versus 4.8%; p = 0.578). Conclusion:In this registry, we provide a description of ACS patient, which allows the evaluation of the demographic characteristics, medical treatment prescribed, and in-hospital mortality. A greater awareness of our reality may help the medical community to adhere more strictly to the procedures set by guidelines.key words: Acute coronary syndrome, registry, chest pain, unstable angina, acute myocardial infarction.

SummaryBackground: The probability of adverse events estimate is crucial in acute coronary syndrome condition.