This study examined the effects of physical training on exercise hyperpnea (EH) in patients on hemodialysis (HD) . In baseline, 17 (trained group) and 12 (control group) patients on HD performed symptom limited exercise test using a treadmill. Trained group, but not control group, exercised 2 to 3 times weekly on non-dialysis days under medical supervision. Exercise testing was repeated 20 weeks after the baseline. Ventilatory response to exercise was evaluated using the regression slope relating minute ventilation (VE) to carbon dioxide output (VCO₂ ) during incremental exercise (VE/VCO₂ slope) below the point of respiratory compensation. In trained group, VE, oxygen uptake ( VO₂) and VCO₂ at peak exercise increased and VE/VO₂ and VE/VCO₂ decreased after physical training, respectively. No change was observed in control group. VO₂ at the anaerobic threshold increased in trained group, but not in control group. The post training VE/VCO₂ slope (33.9±5.0) was significantly (p<0.05) lower than the pre-training slope (38.0± 4.8) and remained constant in control group. In trained group, changes in the VE/VCO₂ slope correlated with those in peak VO₂ (p<0.05) . These results suggest that physical training decreases EH in patients on HD and that it correlates with changes in exercise tolerance.