Effects of Controlled Breathing on Cardiorespiratory Variables in Multiple Myeloma

Inclusion Criteria: * Age ≥ 18 years. * Confirmed diagnosis of multiple myeloma, currently undergoing active treatment with daratumumab, and under clinical follow-up by the Hematology Department of HU12O. * Explicit medical indication for supervised physical activity issued by the responsible hematologist and documented in the medical record. * No scheduled hematopoietic stem cell transplantation within the 60 days following the planned start date of the intervention (verified through medical record review). * Functional status of ECOG 0-2 (Eastern Cooperative Oncology Group), assessed by a healthcare professional from the Hematology Department, ensuring the ability to perform at least basic and light instrumental activities of daily living, including independent ambulation. * Access to a smartphone with stable internet connection, required for monitoring and recording adherence to the intervention. * Ability to provide written informed consent, demonstrating understanding of the study's nature, purpose, and procedures. Exclusion Criteria: * Medical risk contraindicating exercise or breathing techniques: * Clinically significant cardiovascular disease, including:decompensated heart failure, acute myocardial infarction within the past 3 months, clinically uncontrolled arrhythmias, unstable angina, acute-phase deep vein thrombosis or pulmonary embolism, pacemakers or cardiac devices whose monitoring parameters contraindicate supervised exercise according to cardiology. …