The Effects of Positive Expiratory Pressure Breathing on The Rate of Post-exercise Recovery in Patients With COPD

Most daily activities involve alternating periods of exercise and rest. If recovery is slow following exercise it means that the next period of activity may be more difficult and the COPD patients becomes restricted in their daily life. Therefore, the investigators are interested to study the effectiveness and physiological effects of breathing with a PEP device during post-exercise period and hypothesize that 1. Post-exercise breathing with PEP device will increase the rate of recovery more than breathing without PEP device. 2. Post-exercise breathing with PEP device will not create harmful effects on cardiopulmonary function in COPD patients.