Benefits of a 6-month, Individualized, Hybrid, "Real-life" Adapted Physical Activity Program on the Quality of Life of Patients Treated for Multiple Myeloma

The goal of this clinical trial is to evaluate the effect of a long-term, individualized, hybrid adapted physical activity program on the quality of life of patients with multiple myeloma. The main question it aims to answer are : Does this logn term, individualized and hybrid adapted physical activity program improve quality of life in multiple myeloma patient ? What are the effects of this program on effort tolerance, pain, muscular mass, osteolytic lesions, tolerance to treatment, response to treatment? If there is a comparison group: Researchers will compare \[arm information\] to see if \[insert effects\]. Participants will be randomised in 2 groups. * control group: patients will receive only advices about physical activities benefit * interventional group: This group will be offered a program of adapted physical activities mixing sessions at home (remote) and sessions at the hospital (in person).