Avaliação da freqüência cardíaca de repouso: auto-avaliação, ritmicidade e predição

Abstract

The HRres is used for the prescription of aerobic exercise, control of training loads, and is used as an indicator of risk factors. The measure of HRres should be collected in the morning to wake up and is not always possible to make an appropriate assessment due to methodological problems. The HRres also changes according to time of day, with its pattern already established in previous studies. Knowing the difficulty of measurement and the influence of exogenous factors throughout the day, the study objectives were to determine: 1) The reliability of intra-and interday HRres; 2) The rhythmicity of HRres at different times of day when individuals with different patterns of physical activity; 3) Predicting the HRres through regression equation. The sample consisted of 107 subjects, 69 men and 38 women, intentionally chosen for convenience. For the study 1, 17 individuals were evaluated and subjected to 3 measurements HRres, two in the laboratory (Lab 1 and 3 min after Lab 2), and another at home (House). For study 2, 90 subjects were evaluated by the level of physical activity, identified by the questionnaire of habitual physical activity in which the sample was divided into 2 groups, A (most active) and B (less active) respectively, and the subjects were self-evaluated at different times of the day: 6, 9, 12, 15, 18, 21 e 24 h. For the study 3, using data from study 2, we adopted the value of 6 h as reference, thereafter the values were normalized and presented by the %mean increase per hour. Was made a quadratic fit to predict HRres 6 h. ANOVA was performed, "t" Student test and Pearson correlation (p <0.05). In study 1, the values recorded by the subject were: Lab 1: 67 ± 7,1 bpm; Lab 2: 66 ± 6,6 bpm and House: 68 ± 6,8 bpm and the evaluator: Lab 1: 67 ± 7,0 bpm; Lab 2: 66 ± 6,8 bpm. There were no significant differences between the collections. On the rhythmicity of HRres investigated in Study 2, there was no difference between the group more active and less active. Values HRres at different times of day were 62 ± 8,6 (6h), 66 ± 9,9 (9 am), 67 ± 10,1 (12h), 68 ± 9,2 (15h), 69 ± 9,5 (18h), 66 ± 8,9 (21h) and 64 ± 10,1 (24). The study 3 was conducted based on the data of the study 2, in which it was possible to predict the HRres with r values between 0.70 and 0.83 and a standard error of estimate between 4,8 and 6,2 bpm depending on the time of the collection. It follows that individuals are able to self-evaluation, independent of time and place of the evaluation. The HRres is not changed as to its rhythm in individuals with different patterns of physical activity. We can predict the HRres through a simple equation.