BACKGROUND Survival prognosis in haematological malignancies has improved considerably, however the frequency and impact of the most prevalent and debilitating symptoms - cancer related fatigue (CRF) - has not improved. Up to 40% of cancer patients has daily difficulties due to CRF and fatigue and weakness is affecting 2/3 of patients. In contrast to everyday fatigue CRF is defined as an unusual and persistent sense of tiredness, weakness, or even exhaustion that is not relieved by rest or sleep and leads to decreased physical or mental capacity.