Inclusion Criteria:

• Age >= 18 years of age

• Have an Eastern Cooperative Oncology Group (ECOG) Performance Status of:

  • Module A: ECOG 0 - 1
  • Module B: ECOG 0 - 2
  • Module C: ECOG 0 - 2
• Have a diagnosis of smoldering multiple myeloma or multiple myeloma
• Show no signs of comorbidities, myeloma symptoms, or treatment side effects that would put them in danger when participating in the study according to the physician's discretion
• Are able to understand and follow assessment and intervention procedures
• Participant must understand the investigational nature of this study and sign an Independent Ethics Committee/Institutional Review Board approved written informed consent form prior to receiving any study related procedure
• MODULE A (PHYSICAL ACTIVITY): Participant has access to a personal computer or tablet with camera, microphone, speakers and internet access
• MODULE B (NUTRITION): Not applicable
• MODULE C (BETA BLOCKER): Newly diagnosed patients with multiple myeloma necessitating treatment and before initiation of systemic therapy
• MODULE C (BETA BLOCKER): Eligibility for autologous stem cell transplantation
• MODULE C (BETA BLOCKER): Bone marrow biopsy planned as standard of care at first diagnosis and before stem cell collection (Flow Cytometry Standard of Care [SOC] - III)
• MODULE C (BETA BLOCKER): Female participants of child-bearing potential must have a negative pregnancy test at study entry and then agree to use adequate contraceptive methods (e.g., hormonal or barrier method of birth control; abstinence) prior to study entry. Male patients with female partners of child-bearing potential should also use adequate contraceptive methods (see above). Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately
• CRITERIA FOR SELINEXOR SUBSTUDY: Age >= 18 years of age
• CRITERIA FOR SELINEXOR SUBSTUDY: Multiple myeloma with planned treatment with selinexor or one of its combinations (to include selinexor/bortezomib/dexamethasone [SVd], selinexor/carfilzomib/dexamethasone [SKd], selinexor/pomalidomide/dexamethasone [SPd], and selinexor/daratumumab/dexamethasone [SDd])
• CRITERIA FOR SELINEXOR SUBSTUDY: Have an ECOG Performance Status of 0 - 2
• CRITERIA FOR SELINEXOR SUBSTUDY: Show no signs of comorbidities, myeloma symptoms, or treatment side effects that would put them in danger when participating in the study according to the physician's discretion
• CRITERIA FOR SELINEXOR SUBSTUDY: Are able to understand and follow assessment and training procedures
• CRITERIA FOR SELINEXOR SUBSTUDY: Participant must understand the investigational nature of this study and sign an Independent Ethics Committee/Institutional Review Board approved written informed consent form prior to receiving any study related procedure

Exclusion Criteria:

• Major comorbidities that would cause danger to the patient when participating in the study and that would have a risk of progression if the patient took part in the study (including, but not limited to): cardiac or pulmonary and infectious diseases (e.g., ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia) or, psychiatric illness/social situations that would limit compliance with study requirements
• Unwilling or unable to follow protocol requirements
• Any condition which in the investigator's opinion deems the participant an unsuitable candidate to take part in study intervention (comorbidities, myeloma symptoms, treatment side effects)
• MODULE A (PHYSICAL ACTIVITY): Current and symptomatic pathological fracture(s) or severely advanced instability of the musculo-skeletal system that is deemed to making the patient unsafe to participate. This will be assessed by radiologist, a neurosurgeon and/or an orthopedic surgeon
• MODULE A (PHYSICAL ACTIVITY): Current and symptomatic pathological fracture(s) or severely advanced instability of the musculo-skeletal system
• MODULE A (PHYSICAL ACTIVITY): Acute bone instability as assessed by whole body low-dose computed tomography and evaluated by an experienced surgeon
• MODULE B (NUTRITION): Clinical signs of malnutrition (body mass index [BMI] < 18)
• MODULE B (NUTRITION): Special diets (physician prescribed)
• MODULE B (NUTRITION): Diabetic treated with glucose-lowering medications and/or insulin
• MODULE B (NUTRITION): Other reasons not to withhold food
• MODULE B (NUTRITION): Any condition which in the investigator's opinion deems the participant an unsuitable candidate to limit food consumption
• MODULE C (BETA BLOCKER): Contraindications to the use of beta-blockers, e.g.; severe sinus bradycardia; sick sinus syndrome; or heart block greater than first-degree, uncontrolled depression, unstable angina pectoris, uncontrolled heart failure (New York Heart Association [NYHA] Grade III or IV), hypotension ( systolic blood pressure < 100 mmHg), severe asthma or chronic obstructive pulmonary disease (COPD), uncontrolled type I or type II diabetes mellitus (HbA1C > 8.5 or fasting plasma glucose > 160 mg/dL at screening), symptomatic peripheral arterial disease or Raynaud's syndrome, untreated pheochromocytoma, current calcium channel blocker use (Non-dihydropyridines such as verapamil) or rhythm control agents such as digoxin and amiodarone. Patients with pacemakers will be excluded
• MODULE C (BETA BLOCKER): Pregnant or nursing female participants, where pregnancy is defined as the state of a female after conception and until the termination of gestation, confirmed by a positive human chorionic gonadotropin (hCG) laboratory test