The evaluation of a 13-month maintenance program (MP) for 39 severe COPD patients with FEV(1)%pred 44(7)% who, as result of two different 8-week leg exercise training (LET) programs, one supervised at the hospital (group S; n = 20) and the other self-monitored (SM; n = 19), had achieved different levels of exercise tolerance. After LET, patients in group S had a higher maximal oxygen uptake and endurance time than patients in the SM group O(2)max 1.43(0.30) l. min(-1) vs l.25(0.27) l. min(-1) and endurance-time 16(4) min vs 12 (5) min, respectively). During the MP patients were advised to walk vigorously at least 4 km/day, 4 times/wk. After the MP, while endurance time remained higher than at baseline, it had decreased ( p < 0.01) immediately after LET in both groups and no differences were evident between groups (11(4) min and 10(4), respectively). In contrast, Chronic Respiratory Diseases Questionnaire scores, which had improved significantly after LET in both groups, remained high. Long-term effects of MP were independent of the training strategy or whether physiological improvements had been obtained with the initial LET. SM exercise programs do not seem capable of maintaining physiological improvements in exercise tolerance, though "quality of life" can be maintained.