Abstract
The effects of two 8 week programmes of reconditioning in chronic obstructive pulmonary disease (COPD) patients were studied. Forty one subjects (mean+/-SD) 644.5) yrs; forced expiratory volume in one second (FEV1) 1.09+/-0.16 L; 40.6+/-6.2% predicted were randomly assigned either to supervised training on a treadmill, 4 days x week(-1) (group S; n=21) or walking 3 or 4 km in 1 h 4 days x week(-1), self-monitored with a pedometer, with weekly visits to encourage adherence (group SM; n=20). Patients were evaluated with the chronic respiratory diseases questionnaire (CRQ) and two exercise tests on a treadmill: incremental (IT) and constant (CT), above lactic threshold or 70% of maximal oxygen uptake (VO2, max) with arterial blood lactate determinations. Estimated mean work rate of training was 69+/-27 W and 25+/-5 W respectively for groups S and SM. Both types of training produced similar changes in the four dimensions of the CRQ. In group S reconditioning yielded significant (p<0.05) increases in VO2, max and increases in duration, with decreased lactate accumulation, ventilation, CO2 output (VCO2), heart rate (HR) and diastolic blood pressure (DBP) at the end of CT. They also adopted a deeper slower pattern of breathing during exercise. The SM group showed significant (p<0.05) increases in duration, lower HR and DBP at the end of CT. Significantly (p<0.05) different effects between S and SM programmes were changes in VO2, max 100+/-101 mL x min(-1) versus 5+/-101 mL x min(-1)), duration of the CT (8.1+/-4.4 min versus 3.9+/-4.7 min), VCO2 (-94+/-153 mL x min(-1) versus 48+/-252 mL x min(-1)), lactate accumulation (-1.3+/-2.2 mmol x L(-1) versus 0+/-1.2 mmol x L(-1) and respiratory rate at the end of CT (4.3+/-3.4 min(-1) versus -1+/-4.2 min(-1)). Supervised, intense training yields physiological improvements in severe chronic obstructive pulmonary disease patients not induced by self-monitored training. The self-monitored, less intense training, increases submaximal exercise endurance, although to a lesser degree.
