Breast cancer (BC) is the most common neoplasia. Frequent for women and half of the new cases occur in people over 65 years of age. The treatment of BC generates adverse effects that deteriorate the physical functionality, muscle strength and quality of life of the survivors. This is more noticeable in elderly BC survivors. Physical exercise improves some adverse effects of BC, but few studies have focused on physical functionality, especially in older people. The elderly population reports the lowest adherence and lower level of physical activity. It is relevant to explore innovative and specific proposals for physical exercise for elderly survivors of BC. One solution may be virtual reality game-based exercise, which has been shown in healthy older people to significantly improve physical functionality and adherence compared to traditional physical exercise. The objective of our study is to estimate the feasibility and effect of a virtual reality-based exercise program on the functionality, muscle strength, and quality of life of older BC survivors, compared to a group undergoing traditional physical exercise.

This is a randomized controlled study. It will be conducted at the Dr. Sotero del Río Assistance Complex, which receives Southeast Metropolitan Health Service patients. Participants: 60 women over 60yrs who completed their antineoplastic treatment at least two years ago will be recruited.

Functionality will be measured using the Short Physical Performance Battery (SPPB), which is specific for older individuals. Hydraulic Dynamometry (Jamar © hydraulic hand dynamometer) will evaluate isometric upper limb muscle strength. Quality of life shall be assessed using the EORTC QLQ C30 Quality of Life Questionnaire - with its EORTC QLQ-ELD14 module, validated in the Chilean population. Feasibility will be measured using recruitment rate (≥50%), retention rate (≥ 80%), adherence rate (75% of total sessions ≥14 sessions), and incidence of adverse events.

Candidates will be randomly assigned to either virtual reality or traditional exercise groups. Both training groups will involve supervised sessions twice a week for nine weeks. The traditional exercise group exercises will be for arms and legs, involving body weight and external weights. Meanwhile, the virtual reality group will follow a physical exercise protocol using the "Nintendo Wii Fit" console. After the 9th week, participants will be evaluated one month after completing the training program.

Inclusion Criteria:

• Women between 60 and 80 years old.
• Diagnosis of primary breast carcinoma.
• Treated with at least two of the following treatments: surgery, radiotherapy, chemotherapy, hormone therapy, biological therapy.
• Minimum of 2 years and a maximum of 10 years after finishing treatments (surgery, chemotherapy, and radiotherapy).
• Being able to walk at least 4 meters independently or with a cane as assistive technology

Exclusion Criteria:

• Stage IV breast cancer.
• Previous cancer treatment for any type of cancer other than breast cancer (chemotherapy, radiotherapy, or endocrine therapy).
• Cognitive impairment measured by the abbreviated Mini-Mental State Examination with a score < 13 points.
• Medical contraindication to perform physical exercise.
• Self-reported of physical activity equivalent to the recent American College of Sports Medicine Exercise Guidelines for Cancer Patients and Survivors (150 min/week of moderate aerobic exercise and strength exercise twice a week).
• Body mass index < 18.5 kg/m2 or > 40 kg/m2.