Chronic Fatigue Management in Immunotherapy: A German–Slovenian Collaboration for Precision Exercise Oncology

Abstract

Cancer-related fatigue (CRF) is one of the most common and disabling side-effects of cancer treatment. While we know that exercise can reduce fatigue in patients receiving chemotherapy or radiotherapy, very little is known about why fatigue develops—and how it can be improved—in patients treated with modern immunotherapy, especially immune checkpoint inhibitors (ICI). Up to one-third of people receiving ICIs experience long-lasting fatigue, even when their cancer responds well to treatment.

This project brings together experts from the University Hospital Cologne in Germany and the Science and Research Centre Koper in Slovenia. Cologne offers a unique clinical setting where exercise therapy is fully integrated into cancer care, allowing patients to receive structured and supervised training during treatment. The Slovenian team contributes advanced tools to skeletal muscle metabolism and function, including imaging and non-invasive methods such as near-infrared spectroscopy (NIRS), and tensiomyography (TMG). Together, we will explore how skeletal muscle functions during exercise in patients undergoing immunotherapy, and why some individuals develop more severe chronic fatigue than others. We will also investigate how aging and physical inactivity affect muscle metabolism, and whether real-time muscle oxygenation monitoring can improve the way exercise programs are tailored to each patient.

The goals of the project are to:

• Understand the biological mechanisms behind chronic fatigue in patients receiving ICI treatment.
• Test how structured exercise programs can reduce fatigue and improve well-being.
• Strengthen long-term, cross-border collaboration between Germany and Slovenia in the field of exercise oncology.

Findings will be shared with clinicians, researchers, and policymakers through workshops in Cologne and Koper. The project will also support future EU research proposals and help establish Cologne’s integrated exercise therapy model as a leading example for cancer care across EU.
 

Dr. Miloš Kalc

Dr. Miloš Kalc is a Research Assistant at the Institute for Kinesiological Studies at the ZRS Kope) in Slovenia. His research focuses on neuromuscular physiology, with a particular emphasis on fatigue, potentiation, and the effects of unloading. He is especially interested in spinal inhibition and advancing its assessment by implementing new technologies such as high-density surface electromyography (HDsEMG).

He received his PhD from the University of Ljubljana in 2022, with a doctoral thesis on the acute effects of whole-body vibration on the neuromuscular system. Miloš’s research interests include neuromuscular fatigability, motor unit behavior, spinal inhibition, and the development of novel assessment methodologies. He has collaborated on research published in leading journals such as the Journal of Applied Physiology, IEEE Transactions on Neural Systems and Rehabilitation Engineering, Journal of Neurophysiology, and Experimental Physiology. His work often explores the effects of interventions like bed rest, whole-body vibration, and various training modalities on the nervous and muscular systems.