Patients assigned to intervention group A will follow a supervised programme of physical activity and exercise at home and during their hospital stay. These recommendations are designed and supervised by a physiotherapist. The programme will include three weekly aerobic exercise sessions and two resistance exercise sessions, as recommended in the literature. Each session will last approximately 35 minutes and will include a warm-up, training and cool-down.

All patients will follow the same exercise programme, which will be adapted to a basic, intermediate and advanced level to adapt to the patients' physical condition. The loads, intensity and number of sets will be adapted for each level.

The programme is scheduled to commence one month prior to the initiation of CAR-T therapy. It is recommended that patients adhere to the professional's guidelines for a period of at least one month following treatment.

The intervention combines a structured physical activity programme with individualised nutritional recommendations based on the Mediterranean diet. These recommendations are designed and supervised by a nutritionist and a physiotherapist. The macronutrient distribution followed standard guidelines (50-55% carbohydrates, 30-35% fats, 10-15% proteins), emphasising vegetables, fruits, legumes, cereals, dairy, lean meats, fish, nuts, and olive oil. Each food group contributes bioactive compounds with anti-inflammatory and antioxidant properties, including lycopene, quercetin, anthocyanins, genistein, ferulic acid, SCFAs, omega-3 fatty acids and polyphenols. These have been shown to mitigate oxidative stress, inflammation and toxicological effects, thereby supporting cardio.

The programme is scheduled to commence one month prior to the initiation of CAR-T therapy. It is recommended that patients adhere to the professional's guidelines for a period of at least one month following treatment.

Patients assigned to intervention group A will follow a supervised programme of physical activity and exercise at home and during hospitalisation. All patients will follow the same exercise programme, which will be adapted to a basic, intermediate and advanced level to suit the patients' physical condition. The loads, intensity and number of sets will be adapted to each level.

Aerobic exercise will consist of walking and/or cycling at an intensity of between two and five on the Borg perceived exertion (RPE) scale. Resistance exercise will consist of one session focusing on the trunk and upper limbs, and another on the lower limbs. Both sessions will include seven exercises, performed at an intensity of between three and four on the Borg RPE scale.

Patients will undergo a standardised neurological assessment. Neurotoxicity will be graded according to version 5.0 of the Common Terminology Criteria for Adverse Events (CTCAE). The Immune Effector Cell-Associated Encephalopathy (ICE) score will also be used to evaluate five cognitive domains, for which the maximum possible score is 10. The following will be assessed: orientation (year, month, city, hospital; 4 points); object naming (three objects; 3 points); following commands (two-step command; 1 point); writing a coherent sentence (1 point); and attention (counting backwards from 100 in tens; 1 point). Lower ICE scores reflect greater neurological impairment.

Functional capacity will be assessed using the Lawton and Brody Instrumental Activities of Daily Living (IADL) scale . This instrument evaluates the patient's ability to perform eight instrumental activities essential for independent living (e.g., using the telephone, shopping, preparing meals, housekeeping, laundry, transportation, medication management, and financial management). Each item is scored as 0 (dependent) or 1 (independent), yielding a total score ranging from 0 (total dependence) to 8 (complete independence). Higher scores indicate greater independence and better functional status.

Duration of the initial hospitalisation following CAR-T infusion will be documented from the day of admission until discharge (days).