Physiological Response to Moderate Exercise Workloads in a Pulmonary Rehabilitation Program in Patients With Airflow Obstruction: Materials and Methods
Patients
Outpatients with COPD were referred to the rehabilitation program by their attending chest physicians at the Sunderland Royal Hospital. Prior to entering the program, all patients met the following criteria: (1) a FEV1 < 70% predicted and a FEVj/FVC < 65%; (2) nonsmokers for a minimum of 2 months; (3) their medical therapy had been optimized; and (4) no clinical evidence of exercise-limiting cardiovascular or neuromuscular diseases. The patients enrolled into the study were clinically and physiologically stable; patients who had been hospitalized or had suffered an exacerbation of their airflow limitation within 2 months prior to the start of the study were excluded. A total of 70 patients were originally recruited to the rehabilitation program. Only 60 patients (38 men; FEV1 range, 0.51 to 2.99 L) completed the regimen (the training group) and are presented in this report; the remaining 10 patients failed to complete because of intercurrent pulmonary infection and noncompliance with the training schedule. An additional 15 patients (8 men; FEV1 range, 0.55 to 2.91 L) who originally declined to participate in the rehabilitation program because of time constraints agreed to undertake the required assessments before and after the 12-week study period (the nontraining control group). The demographic characteristics of both the training and nontraining control groups are given in Table 1. The study protocol was approved by the University of Sunderland and Sunderland Health Authority ethics committees, and all patients gave informed consent prior to participation in the study. so
Outcome Measurements
The patients visited the pulmonary function laboratory at Sunderland Royal Hospital for a half-day session and performed pulmonary function and identical incremental symptom-limited cycle ergometer tests immediately before and after the 12-week study period.
Table 1—Physical Characteristics, Lung Function, and Exercise Capacities of the Patients in the Training and Nontraining Control Groups at the Outset of the Study
| Variables | TrainingGroup(n = 60) | Nontraining Control Group (n = 15) | Difference |
| Age, yr | 64 ± 1 | 56 ± 3t | 8(0.1, 15) |
| Weight, kg | 71.4 ± 2.2 | 68.3 ± 5.1 | 3.1 (- 8.8, 15.0) |
| Height, cm | 1.65 ± 0.01 | 1.64 ± 0.01 | 0.01 (- 0.03,0.05) |
| % predicted FEVj | 55.1 ± 2.6 | 54.8 ± 4.8 | 0.3 (- 10.9, 11.5) |
| FEVj/FVC, % | 47.9 ± 1.8 | 47.3 ± 3.0 | 0.6 (- 6.6, 7.9) |
| Peak WR, W | 4±77 | 71 ± 8 | 6 (— 13.3, 26.3) |
| Peak Vo2, L/min | 1.14 ± 0.05 | 1.08 ± 0.12 | 0.06 (- 0.22,0.34) |
| Peak Ve, L/min | 42.4 ± 2.1 | 41.1 ± 4.5 | 1.3 (- 9.1, 11.6) |
Category: Airflow Obstruction
Tags: COPD, exercise training, pulmonary rehabilitation