Modulated Mid-frequency Whole-body Electromyostimulation and Nutritional Therapy in Gastrointestinal Cancer Patients

Inclusion Criteria: * Patients with oesophageal, gastric, duodenal, colon or rectal cancer following surgery without further therapy and with neoadjuvant and adjuvant therapy * medical clearance for exercise training * written declaration of consent from the study participant Exclusion Criteria: * Participation in another study on the topic of exercise or nutrition * Electronic implants such as pacemakers, pumps, and coronary stents * Cardiac arrhythmia * Implants in the area of application (e.g. breast implants) * Pregnancy * Epilepsy * Wounds and open skin diseases in the area of application of the electrodes * Unhealed operations or bone fractures * Acute inflammatory diseases (e.g. inflammation of the intervertebral discs, bones, vessels, or soft tissue) * Directly after herniated discs or other instabilities such as large abdominal wall hernias * Blood clots (thromboses) * Bone diseases with high-grade osteoporosis * Increased risk of haemorrhage * Fever and illnesses that can be aggravated by physical exertion * Untreated high blood pressure * Blindness * Continuous parenteral nutrition * Metal and electronic parts in the body (e.g. prostheses, metal vascular clips, hearing aids/inner ear/cochlear implants, magnetic dental prostheses, pacemakers, contraceptives)