Within the last decades exercise oncology research has established a vast body of evidence that exercise has multifactorial benefits for cancer patients. Recognizing this scientific evidence, leading expert associations like the American Cancer Society, National Comprehensive Cancer Network, and American College of Sports Medicine have published recommendations to inspire cancer patients to increase their everyday physical activity (PA). However, these recommendations are highly unspecific and do not consider patients individual needs, abilities and skills. Therefore, the proposed project aims to fill this gap by developing personalized therapeutic modules that fit individual patient?s needs, abilities and skills. In a cross-sectional approach we aim to determine groups of patients that are trait-homogenous according to their attitudes, beliefs and competences about exercise and physical activity on one hand and how these personal factors correspond with treatment-related side effects. To increase generalizability of these results the cross-sectional survey will be conducted at the Pennsylvania State University in Hershey, USA and at the National Center for Tumor Diseases in Heidelberg, Germany. By this bi-national approach, cultural differences and distinct health-care systems will explicitly be taken into account. Based on the found patient-clusters, personalized intervention modules addressing the patient-clusters special needs should be developed and tested in future studies.