High Intensity Aerobic Exercise Training and Immune Cell Mobilization in Patients With Lung Cancer (HI AIM)

Inclusion Criteria: * Metastatic non-small cell lung cancer * Measurable disease according to RECIST 1.1 * Age ≥ 18 years * Treatment with immune checkpoint inhibitors, checkpoint inhibitors combined with chemotherapy or oncological surveillance * Eastern Cooperative Oncology Group (ECOG) performance status score (PS) ≤2 * Preferably metastasis suitable for biopsy * Normal marrow function as defined below: * White blood cell count (WBC) ≥ 2 x 10⁹/L * Absolute neutrophil count (ANC) ≥ 1.5 x 10⁹/L * Hemoglobin ≥ 6.0 mmol/l * Platelet count ≥ 100 x 10⁹/L * In case, a patient's bone marrow values fall slightly below the described values, the treatment responsible doctor will be consulted. The general health and the ability to proceed with the treatment will be considered. * Ability to speak and read Danish * Willingness to give informed consent for participation in the study Exclusion Criteria: * Any physical condition that hinder the execution of physical exercise, as assessed by the referring oncologist and by a physiotherapist * Severe dyspnea that hinder the execution of high intensity aerobic exercise training, as assessed by the referring oncologist * Symptomatic brain metastases * Dementia, psychotic disorders, or other cognitive diseases or conditions that hinder participation in a clinical exercise-based trial, as assessed by the referring oncologist * Unstable medical disease or history of serious or concurrent illness; any medical condition that might be aggravated by exercise training or that cannot be controlled, including, but not restricted to congestive heart failure (NYHA class III-IV), unstable angina pectoris, implantable cardioverter defibrillator (ICD), or myocardial infarction within 6 months * A condition requiring systemic treatment with either corticosteroids (\> 10 mg daily prednisone equivalents) or other immunosuppressive medications. Inhaled or topical steroids and adrenal replacement doses ≤ 10 mg daily prednisone equivalents are permitted * Use of beta blockers * Any systemic infections within the last 4 weeks * Patients who receives chemotherapy as monotherapy * In patients with documented bone metastases; patients with: * A bone metastatic burden or location that poses a risk of injury in the performance of exercise training, as assessed by the referring oncologist