Inclusion Criteria:  Adolescents and young adults between 15 and 45 years of age Completion of acute cancer treatment and receiving follow-up care in Essen (University Hospital Essen) At least 12 months post endoprosthesis implantation Signed informed consent (Parents and Patient)  Exclusion Criteria:  <15 years of age, >45 years of age time post implantation <12 months Medical condition that limits participation in one of the study arms Inability to follow the training-protocol