Diffuse large B cell lymphoma is the most common histology of non-Hodgkin's malignant lymphomas (31% of lymphomas), with an incidence of between 15 and 20 new cases per year per 100,000 inhabitants in France. The median age is 65 and a third of patients are over 75 years old. 60% of patients are cured after a standard regimen of chemotherapy with RCHOP; 40% of patients will, however, relapse. No other regimen has shown improvement in overall survival, but poor prognosis factors have been identified. Beyond these factors, other prognostic factors can impact overall and progression-free survival: sarcopenia, nutritional status disorders Sarcopenia is defined by the reduction of muscle mass and strength. It was first described in the elderly and classified as geriatric syndrome such as dementia, falls or frailty. It varies from 5 to 13% between 60 and 70 years and between 11 and 50% beyond 80 years and is classified as primitive, that is to say related to age It can however be secondary to neoplasia. This event has been described in patients with hematologic malignancies during chemotherapy and can reach 55% of patients in the elderly. It is proportional to the intensity of the treatments. It emerges as an independent prognostic factor which is detrimental to survival in these patients. Physical exercise combined with nutritional support could reduce it.

The positive impact of adapted physical activity has been shown in numerous publications on reducing the incidence and risk of relapse for certain cancers (breast, colon prostate). It is less obvious in hematology in view of studies published on adapted physical activity . Adapted physical activity seems to provide a survival benefit in diffuse large cell B lymphoma however the number remains too low in this histology.

Sarcopenia is an often-underestimated event and is associated with older age, co-morbidities, increased infectious complications, and early mortality.

Correcting sarcopenia through appropriate physical activity could reduce its negative prognostic impact.

The aim of the study is to increase the event-free survival of patients in the RCHOP and adapted physical activity arm by 15% compared to the standard arm.

Inclusion Criteria:

1. Patient with diffuse large-cell B lymphoma regardless of the WHO 2016 classification subtype, or low-grade B lymphoma immediately transformed into high-grade B lymphoma (follicular lymphoma of the marginal zone, MALT, lymphocytic, lympho-plasma cells),
2. Treatment naïve or having benefited from 2 cycles of chemotherapy (prephase or COP and cycle n ° 1 of RCHOP) if Performance Status> 3 linked to hemopathy and reversible (≤ 2)
3. Aged ≥ 65 years old,
4. Eligible for treatment with RCHOP, regardless of the IPI score adjusted for age,
5. Performance Status ≤ 2,
6. Patient affiliated to a social security scheme,
7. Patient who has given written consent before any specific procedure related to the study

Exclusion Criteria:

1. Any other type of lymphoma (T lymphoma, Burkitt's lymphoma, non-transformed low-grade B lymphoma, etc.),
2. Cerebral or meningeal damage related to hemopathy,
3. Acquired or congenital motor or sensory deficit which does not allow the completion of APA sessions,
4. Uncontrolled arterial hypertension,
5. Disabling heart or respiratory failure not allowing the completion of APA sessions,
6. Disabling osteo-articular or muscular pathology,
7. LVEF <50%,
8. Patient having received 3 or more cycles of 1st line chemotherapy,
9. Pregnancy or breastfeeding,
10. Active viral infection: hepatitis B, C and HIV,
11. Persons deprived of their liberty or under guardianship
12. Dementia, mental alteration or psychiatric pathology which could compromise the patient's informed consent and / or compliance with the protocol and follow-up of the trial,
13. Patient who can't follow protocol for psychological, social, family or geographic reasons