In brief: The purpose of this study was to determine the feasibility and physiological effects of mild steady-state exercise during hemodialysis treatment. Three men and three women pedaled a Monark bicycle ergometer at 150 kgm min1for five minutes during the first hour of hemodialysis treatment. Heart rate, blood pressure, pH, Hco3, and respiratory and blood gases were analyzed before hemodialysis treatment, at rest just before exercise, during exercise, and at selected times during the first hour of recovery. The authors concluded that all the physiological responses during hemodialysis treatment were typical of a deconditioned person responding to low-level exercise. The rise in blood pressure and arterial oxygen tension may have positive implications for hemodialysis treatment. Further investigation is warranted into the value of using exercise during hemodialysis treatment as a means of training.