[Evaluation of exercise intensity for pulmonary rehabilitation in patients with chronic obstructive pulmonary...

To investigate proper methods and parameters of exercise intensity in pulmonary rehabilitation for patients with chronic obstructive pulmonary disease (COPD).

Symptom-limited cardiopulmonary exercise test (CPET) was performed in 30 male patients with moderate to severe COPD by cycle ergometer. Exercise intensity parameters, including the measured heart rate reserve (HRR%meas), the predictive heart rate reserve (HRR%pred) and the Borg scale were obtained. The distribution of these parameters ranged from 10% to 90% VO2max were compared. Multiple regression analysis was applied to analyze the relationship among heart rate (HR), the Borg scale and VO2max%.

The HRR%meas was close to VO2max%. The coefficient of variation (CV) of HRR%meas was larger than HRR%pred. The larger was the Borg scale, the smaller was the distribution of VO2max%. While the Borg scale were 3, 4, and 5, the exercise intensity achieved 60%, 72%, and 78% VO2max, respectively. Predicted equation (VO2max%=1.026xHR+27.688xBorg-0.179xHRxBorg-63.313, r=0.920, P=0.00) was obtained.

HRR%meas was a better parameter than HRR%pred for prescribing the exercise intensity. The Borg scale is a simple and applicable method to prescribe and monitor the exercise intensity. It is suggested that Borg scale should reach 4 (moderate dyspnea) in pulmonary rehabilitation for the male patients with moderate to severe COPD. Predicted equation for VO2max% is recommended for monitoring the exercise intensity.