Background: Walking is one of the most commonly recommended activities for sedentary individuals. When performed at the correct intensity, it can provide cardiovascular, respiratory, metabolic, and other benefits by providing a training effect in addition to reducing the risk of death from cardiovascular diseases and other chronic health conditions. Objectives: The primary aim of this study was to assess whether individuals who practiced regular unsupervised walking carry out the activity safely and with sufficient effort intensity parameters to have a positive physiological (training) effect. The secondary objective was to compare the training heart rate (HR) and the stability of the HR within the ideal range of training between the sexes. Method: Individuals were selected from walking tracks within the city of Belo Horizonte, Brazil. The study included subjects from 40 to 60 years of age who had practiced walking for at least two months prior to the study, walking at least three times a week. Individuals who agreed to participate in the survey were asked to walk 15 minutes at their usual pace with their HR measured every 5 minutes using a heart rate monitor. Their average walking HR was compared to the average training HR based on the formula: (220 - age) × 70 to 80% that would result in a positive physiological training effect. Results: Of the 142 individuals evaluated, 25.4% achieved the average training HR. This result was significantly lower than those who did not achieve the average training HR while walking (p=0.002). There were significant differences between men and women who had reached the training HR (p=0.0001). Conclusion: The authors found that individuals who walk regularly performed outside the range of the ideal HR intensity that would cause a positive physiological effect and therefore would probably not achieve a beneficial training effect while walking.

Fundamentos: O Duke Activity Status Index (DASI) avalia a capacidade funcional de pacientes com doença cardiovascular (DCV), mas não há versão validada em português para doenças cardiovasculares. Objetivos: Traduzir e adaptar culturalmente o DASI para o idioma português do Brasil, e verificar suas propriedades psicométricas na avaliação da capacidade funcional de pacientes com doenças cardiovasculares. Métodos: O DASI foi traduzido para o português, verificado pela retrotradução para o inglês e avaliado por um comitê de especialistas. A versão pré-teste foi avaliada pela primeira vez em 30 indivíduos. As propriedades psicométricas e a correlação com o teste de esforço foram verificadas em um segundo grupo de 67 indivíduos. Uma análise fatorial exploratória foi realizada em todos os 97 pacientes para verificar a validade de construto do DASI. Resultados: O coeficiente de correlação intraclasse para a confiabilidade teste-reteste foi de 0,87 e para a confiabilidade entre avaliadores foi de 0,84. O alfa de Cronbach para consistência interna foi de 0,93. A validade concorrente foi verificada por correlações positivas significativas de pontuações do DASI com o VO2 max (r = 0,51, p < 0,001). A análise fatorial mostrou dois fatores que explicaram 54% da variância total, com o fator 1 responsável por 40 % da variância. A aplicação do DASI requer entre um e três minutos e meio por paciente. Conclusão: A versão brasileira do DASI parece ser um instrumento válido, confiável, rápido e fácil de administrar para avaliar a capacidade funcional em pacientes com doenças cardiovasculares.

Background: The Duke Activity Status Index (DASI) assesses the functional capacity of patients with cardiovascular disease (CVD), but there is no Portuguese version validated for CVD. Objectives: To translate and adapt cross-culturally the DASI for the Portuguese-Brazil language, and to verify its psychometric properties in the assessment of functional capacity of patients with CVD. Methods: The DASI was translated into Portuguese, then checked by back-translation into English and evaluated by an expert committee. The pre-test version was first evaluated in 30 subjects. The psychometric properties and correlation with exercise testing was performed in a second group of 67 subjects. An exploratory factor analyses was performed in all 97 subjects to verify the construct validity of the DASI. Results: The intraclass correlation coefficient for test-retest reliability was 0.87 and for the inter-rater reliability was 0.84. Cronbach's α for internal consistency was 0.93. The concurrent validity was verified by significant positive correlations of DASI scores with the VO2max (r = 0.51, p < 0.001). The factor analysis yielded two factors, which explained 54% of the total variance, with factor 1 accounting for 40% of the variance. Application of the DASI required between one and three and a half minutes per patient. Conclusions: The Brazilian version of the DASI appears to be a valid, reliable, fast and easy to administer tool to assess functional capacity among patients with CVD.