Cardiorespiratory adaptation of COPD patients to physical training on land and in water

Physical training in water might be included in a comprehensive pulmonary rehabilitation programme, but data on the feasibility and safety of this technique in chronic obstructive pulmonary disease (COPD) patients are lacking. We studied cardiorespiratory parameters of 20 stable COPD patients (10 with forced expiratory volume in one second (FEV1) < 35% of predicted value, and 10 with FEV1 > or = 35% pred) on land and in a temperate-controlled pool (32 degrees C) both at rest and during a 15 min submaximal upper body muscle training programme. Compared to resting values on land, we found in water a decrease of systolic and diastolic blood pressure (14 and 6 mmHg, respectively), rate-pressure product (7%) and lung function (vital capacity (VC) 12%, FEV1 14%, peak expiratory flow (PEF) 18%). There were no differences in heart rate, breathing frequency or O2 saturation. The most strenuous exercise in water resulted in a slightly lower O2 saturation compared to work on land (95 and 93%, respectively), and an increase of Borg rating for dyspnoea from 4 to 5. In spite of the restriction of lung function in water, all patients (even those with FEV1 < 35% pred) performed the training in the pool well, without clinically relevant desaturation, arrhythmia or discomfort. No training session was discontinued due to dyspnoea. We conclude that a 15 min session of submaximal physical training in a pool with a water temperature of 32 degrees C is feasible and safe for nonhypoxaemic normotensive COPD patients without cardiac failure.