IJCS | Volume 32, Nº6, November / December 2019

556 Heart rate (HR) was continuously measured (Oregon Scientific ® , SE128 ® , Portland, Oregon, USA). Peak VO 2 and maximum HR (MaxHR) were recorded at physical exertion of patients. All volunteers met two criteria for peak VO 2 : a) respiratory exchange ratio (RER) ≥ 1.1; b) MaxHR at least equal to 90%of themaximumpredicted for age, using the Jones equation (0.65 x age - 210). The electrocardiographic patterns were recorded and analyzed by a cardiologist during all the test. Training group (TG) The intensity, frequency and duration of the aerobic training sessions were conducted according to the ACSM and the American Heart Association (AHA) recommendations. Each participant underwent 36 walking sessions, which occurred three days a week for 12 weeks, with a minimum of 48 hours of recovery between the sessions. Each session consisted of five minutes of warm-up, which involved movements of the whole body; 30 minutes of continuous walking at moderate intensity – 50-70% of MaxHR, established at the stress test previously performed on the treadmill (Life Fitness ® , model 9700HR ® , Fort Mill, Tennessee, USA); finally, 5 minutes of smooth movements, stretching and breathing. A cardiac monitor (Oregon Scientific SE128 ® , Portland-Oregon), was used individually, according to the HR of each patient every three minutes in all sessions. Each sessionwas conducted under supervision, which promoted safety and accuracy in prescribing individualized training (50-50% of MaxHR), and if necessary, adjusting for the training zone. Control group (CG) The CG continued their usual activities during the study period, without getting involved in exercise. Patients’ follow-up was conducted by telephone every 15 days to assure that the protocol was being followed. Statistical analysis The Kolmogorov-Smirnov test was used to test data normality. Categorical data were expressed as frequency and percentage, whereas continuous data were described as mean and standard deviation. Between-group comparisons (TG x CG) were made at baseline using the unpaired Student’s t-test. Within- group comparisons (pre-training vs post-training) and intergroup comparisons were conducted by the Split-Plot ANOVA, followed by the Bonferroni low or null correlation; post hoc test. The Pearson correlation coefficients (r) used in the study were: 0 < r < 0.25: low or null correlation; 0.25 < r < 0.50: weak correlation; 0.50 < r < 0.75: moderate correlation; and 0.75 < r < 1.00: strong or perfect correlation. The effect size (ES) was defined as mean Cohen’s d greater than 0.2 and lower than 0.5; values between 0.5 and 0.8 were defined as good ES, and values equal to or greater than 0.8 were defined as a large ES. 30 Sample size was calculated considering an alpha error of 5%, statistical power of 90%, and a sample of 80 subjects. The level of significance was set at 5% (p < 0.05) and all analyzes were performed using the Statistical Package for the Social Sciences software, version 20.0. (IBM ® , New York, New York, USA). Results Characteristics of the sample Characteristics of the subjects at baseline are described in Table 1. As expected, all volunteers were elderly. Participants in both groups were classified as normal weight or overweight according to the body mass index (BMI) categories. On the other hand, all subjects had a very low to low cardiorespiratory fitness, as compared with the limits established for the elderly population. 31 The unpaired Student’s t-test did not show any significant difference between the groups. All volunteers participated in 100% of sessions, and no adverse effect was observed during or after the training sessions. Depressive symptoms and physical pain Primary results are shown in Figures 2 and 3. There was a significant reduction in GDS in the TG after 12 weeks of walking training. In contrast both GDS and VAS remained unchanged in the CG (GDS = 3.0 ± 2.7 to 3.1 ± 2.4; p = 0.94; ES = - 0.03; VAS = 4.4 ± 3.2 to 4.2 ± 3.2; p = 0.68; ES = 0.06). Quality of life and peak oxygen consumption QOL (WHOQoL-OLD and WHOQoL-BREF) (Figure 4) and cardiorespiratory fitness (Table 2) were assessed as secondary outcomes. Regarding QOL, no difference was seen between the groups (TG [WHOQoL-OLD= 66.5 ± 14.0 % to 65.6 ± 15.9 %, (p = 0.94, ES = 0.06); WHOQoL- BREF = 67.8 ± 11.0 to 69.4 ± 10.8 (p = 0.21, ES = -0.14)] and CG [WHOQoL-OLD = 64.7 ± 12.3 to 63.2 ± 13.4, Alabarse et al. Depression and pain in healthy active elderly Int J Cardiovasc Sci. 2019;32(6):553-562 Original Article