Apart from the specifically uraemically conditioned decreasing in vitality factors a physically inactivity which originates from the want of the patient or is iatrogenically induced, respectively is one of the causes for the decrease in physical vitality in patients with chronic renal insufficiency. 10 patients with chronic renal disease (serum creatinine 9.2 mg%) after an ergometric test were trained regularly twice a week for 30 minutes with a training intensity which corresponded to 80% of the load intensity. After a training duration of 15 weeks 9 of the 10 patients yielded a better result, in one female patient the bicycle-ergometric effect remained constant. The physical load capacity of the successfully trained 9 patients increased by 22.2 W from 80,5 W to 102.7 W. This corresponds to a 27.6% increase in vitality. After the end of the training the patients achieved a result which is higher than that of untrained patients with renal insufficiency in the same region of insufficiency. In comparison to healthy persons of the same age before the training the patients were to be loaded with 71% and after the training with 92% of the normal. The result of the training can also be read at a decrease of the heart rate and at a shortening of the recreation phase after constant load. The significant decrease of the systolic blood pressure on the 50 W-step indicates to a favourable influence of the RR-behaviour.