Cardiopulmonary stress during exercise training in patients with COPD

¹ Respiratory Rehabilitation and Respiratory Division, University Hospitals, Katholieke Universiteit Leuven, Leuven, Belgium; and Dept of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit Leuven, Leuven, Belgium
² Respiratory Rehabilitation and Respiratory Division, University Hospitals, Katholieke Universiteit Leuven, Leuven, Belgium; Dept of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit Leuven, Leuven, Belgium; and Dept of Physiotherapy, Universidade Estadual de Londrina, Londrina, Brazil

^* To whom correspondence should be addressed. E-mail: Rik.Gosselink{at}uz.kuleuven.ac.be.

	Abstract

Exercise training is an essential component of pulmonary rehabilitation. However, the cardiopulmonary stress imposed during different modalities of exercise training is not known yet. We measured the cardiopulmonary stress of a 12-week exercise training program in 11 COPD patients (FEV₁ 42±12%pred; age 69±6 yrs). Pulmonary gas exchange and heart rate of 3 training sessions were measured with a portable metabolic system at the beginning, midterm and end of the program. Symptoms were assessed with Borg Scores. The exercise intensity was compared to the recommendations for exercise training by the American College of Sports Medicine (ACSM). Training effects were significant (W_max 14±11 Watts, 6MWT 44±36 meters; p<0.05 for all). Whole body exercises (cycling, walking and stair climbing) consistently resulted in higher cardiopulmonary stress (V'O₂, V'E and HR) than arm cranking and resistance training (p<0.05). Dyspnoea was higher during cycling than resistance training (p<0.05). Patients exercised more than 70% (>20 minutes) of the total exercise time above 40% of the V'O₂ reserve and HR reserve ("moderate" intensity according to the ACSM) throughout the program. Exercise training based on guidelines using a fixed percentage of baseline peak performance and symptom scores achieves and sustains training intensities recommended according to the ACSM. In addition, the applied training program resulted in relatively homogeneous V'O₂ responses, while HR response is much more variable. This would not incite for the use of HR to guide training intensity in COPD. The cardiopulmonary stress during resistance training is lower than during whole body exercise and results in less symptoms.