Objectives: To report the results obtained in six-minute walk tests (6 MWT) performed in a group of patients under a pulmonary rehabilitation program (PRP) as a contribution to a better interpretation and the proper use of this test. Some factors that interfere with physical training during pulmonary rehabilitation were also studied. Methods: Retrospective data on 18 males and 5 females under a PRP were evaluated. During 3 months, the patients had 3 weekly training sessions to exercise the muscles of the lower extremities. The following parameters were analyzed before and after training: the distance walked during the 6 MWT and its relationship with the reference values calculated by the equations of Enright and Sherril; forced expiratory volume in one second, training load, heart rate (HR), respiratory rate (RR), oxygen saturation by pulse oxymeter (SpO2) and body mass index (BMI). Results: The values obtained during pre-training 6 MWT did not differ from the reference values calculated by Enright and Sherril equations (P = 0.777). After training, these values differed significantly (P = 0.001). The mean 6 MWT distance increase was 76 m. However, 3 patients did not reach the minimally significant increase of 54 m. Post-training 6 MWT correlated positively with pre-training FEV1 (P = 0.012), but not with load increase during training (P = 0.693). No significant difference in RR and SpO2 was observed before and after training. HR increased significantly at the end of post-training 6 MWT (P = 0.035). In 9 patients BMI was lower than the inferior limit. Six of them (66%) presented post-training distance increased in 54 m or more. Conclusions: The use of standardized methods for 6 MWT performance is recommended, even when reference values are targeted. The equations of Enright and Sherril for healthy subjects tended to yield underestimated values, with no statistical differences in training values in COPD patients. Differences in the encouragement technique employed could explain these conflicting results. Physical gain after rehabilitation was confirmed regardless of the patient's initial functional status, justifying the indication of rehabilitation even to those with severe respiratory limitations. The heterogeneous responses to load increase suggest the analysis of the predictive factors of the best response to training is necessary to customize load increase and thus obtain the best performance possible.

Keywords: Exercise test. Obstructive lung diseases. Rehabilitation. Respiratory function tests. Exercise.

Objective: To describe and analyze clinical symptoms and spirometric alterations of patients with chronic obstructive pulmonary disease (COPD) and history of exposure to wood and tobacco smoke. Methods: We retrospectively evaluated data related to 170 patients distributed into 3 groups: 34 exposed only to wood smoke, 59 patients exposed only to tobacco smoke and 77 patients exposed to both. Results: The groups did not differ significantly in terms of age (p = 0.225) or degree of exposure, considering each type of exposure in isolation or in combination (p = 0.164 and p = 0.220, respectively). Females predominated in the group exposed to wood smoke. There were no differences among the groups regarding respiratory symptoms (p > 0.05), and moderate dyspnea predominated in the three groups (p = 0.141). The group exposed to wood smoke presented higher percentages of forced expiratory volume in one second/forced vital capacity ratio and of forced expiratory volume in one second (p < 0.05). Positive results on bronchodilator testing occurred more frequently in the group exposed to tobacco smoke. The percentage of severe and extremely severe obstruction was significantly higher in the group exposed to tobacco smoke (44.1%) than in that exposed to wood smoke (11.8%; p = 0.006). Conclusions: Respiratory symptoms and pulmonary function alterations consistent with COPD were observed in the groups of patients exposed to wood smoke. However, those alterations were not as significant as the alterations observed in the groups exposed to tobacco smoke. This study emphasizes the importance of prospective studies in evaluating the risk of wood-smoke-related COPD in Brazil, as well as the need for preventive measures in this area.

Keywords: Pulmonary disease, chronic obstructive; Smoking; Air pollution, indoor; Smoke.