Prehabilitation has been demonstrated to be an effective strategy to improve outcomes in patients undergoing some of the abdominal operations. It may increase the physical capacity of the patient, improve postoperative quality of life and even decrease the postoperative morbidity. Currently, the most effective strategy seems to be a trimodal prehabilitation which includes: 1) Nutritional support 2) Psychological support and 3) Physical training.

This study will investigate personalized trimodal prehabilitation for patients undergoing gastrectomy for gastric cancer.

Prehabilitation group:

Patients will undergo 6 Minutes Walking Test (6-MWT), spiroergometry (VO2 max; AT), a grip strength test, a timed Up & Go (TUG) test, 10 m sprint test and sit to stand test before and after prehabilitation. The trimodal intervention will involve:

1. Nutritional intervention: The dietetic physician will perform physical examination and evaluation of the nutritional status to provide individualized care to each patient. Patients will receive personalized recommendations for the prevention or correction of malnutrition.

2. Psychological intervention: Patients will undergo consultation by specialized onco-psychologist. The anxiety and depression level will be evaluated by HAD score and patients will be trained to perform techniques, such as relaxation to reduce and manage anxiety on at home basis.

   The psychologist also will enhance patients' motivation to comply with the exercise and nutritional aspects of the intervention.

3. Exercise intervention: Patients will be consulted by PM&R physicians and physiotherapists and personalized exercise plans will be developed according to the results of 6MWT, AT and VO2peak. Exercises will focus on skeletal muscles and cardiopulmonary function training and the exercises feasible at home basis will be selected. All patients will undergo three supervised training sessions to learn the correct exercise techniques.

All patients will be routinely contacted to ensure compliance with prehabilitation program.

Patients scheduled for surgery first by multidisciplinary tumor board will undergo 4 weeks prehabilitation program, while patients scheduled for perioperative chemotherapy will undergo prehabilitation while neoadjuvant treatment will be administered.

Control group:

Patients will also undergo 6 Minutes Walking Test (6-MWT), spiroergometry (VO2 max; AT), a grip strength test, a timed Up & Go (TUG) test, 10 m sprint test and sit to stand test before surgery or before and after neoadjuvant chemotherapy. Patients will not undergo prehabilitation.

Inclusion Criteria:

• Patient ≥ 18 years old
• Patient agrees to participate in a clinical study
• Patient requires surgical treatment for gastric cancer

Exclusion Criteria:

• Patient requiring surgical treatment for recurrent gastric cancer
• Patient condition not allowing to postpone surgery for at least 4 weeks
• Patients physical or mental condition which will not allow the patient to participate in prehabilitation program