A haematopoietic SCT (HSCT) can cause severe side effects, which may have a profound impact on a patient's life both physically and psychologically. Some studies have shown that physical activity has positive effects for inpatients after an HSCT. Therefore, the question arises whether a controlled exercise programme right from the beginning of the conditioning phase could help contribute to a patient's physical and psychological recovery. To evaluate the different effects of specific, moderate physical activities on the physical and psychological condition of HSCT patients we performed a controlled randomized study with 64 inpatients undergoing an allogeneic or autologous HSCT. The patients were randomly assigned to two groups. Although the training group took part in a specific programme of exercise therapy twice a day throughout the entire hospitalization phase, patients in the control group were offered the hospital's standard mobilization programme. The results of this study showed significant differences in favour of the training group regarding strength, endurance, lung function and quality of life. However, further studies are needed to confirm these results.