Exercise training has been established as a feasible and safe intervention during or after neoplastic treatment in breast cancer patients. Numerous studies have shown that exercise can prevent and control various treatment-related side effects including functional limitation, physical capacity, anxiety and sleep disturbance. In the long-term, an active life style has been demonstrated to increase survival in women, who maintain a moderate level of exercise per week (30 or 75 minutes of brisk walking 5 days per week).

Specifically, active breast cancer survivors have a 51-85% lower cancer specific mortality and 33-82% lower all cause of mortality. But despite this, most breast cancer patients reduce their physical activity levels during and after cancer treatment. In 2010, a roundtable meeting of American College of Sport Medicine published guidelines for cancer survivors, defining that the recommended amount of exercise was 150 minutes per week of aerobic exercise of moderate-intensity and 2 or 3 days per week of strength training that included exercise for major muscle groups. But only 30-47% of breast cancer survivors follow these exercise recommendations.

In most clinical settings, information by the oncologist to keep physical active is part of the recommendation. Yet some breast cancer patients find it difficult to begin or maintain the minimal activity levels recommended by the experts. A typical obstacle includes lack of directions from experts, which can assure the safety and feasibility of the exercise that they perform. Moreover, important personal aspects can have major influence on the exercise preference, including certain food choice and dietary intakes, education level or the preference of a face-to-face exercise counseling by a professional.

A cancer diagnosis is recognized as "teachable moment", where patients are particularly motivated for lifestyle changes. So it is important to approach the patients with adequate interventions that consider the different needs in order to get a healthier behavior among the breast cancer patients.

Taking this into account, the hypothesis of this pilot project is that a guided integrated group exercise program, which includes an educational program on healthy life style, will increase the adherence of breast cancer survivors to exercise and a healthy diet. Therefore the aim of this pilot study was to investigate if a comprehensive and specific group exercise program, which includes dietary and exercise information, could increase leisure-time exercise in women with breast cancer.

This study will be performed as a collaboration between Technical University of Madrid (UPM), Spanish Group of Cancer Patients (GEPAC), Hospital General Universitario Gregorio Marañón, Hospital Universitario Puerta de Hierr y Hospital de Sanchinarro-Madrid del Norte. The project will be carried out at the facilities of the Physical Activity and Sport Science Institute (INEF) and has been approved by the Ethical Committee of the UPM. A single arm pilot project with pre-post test has been designed.

Intervention The exercise program was designed and conducted by a qualified exercise physiologist with oncologic training. The exercise program consisted in a twice weekly supervised training program developed in a social framework. The sessions included instructions in training exercises, as well as included time to speak about their fears and doubts with other patients, who were in the same situation. The intervention lasted 12 weeks (24 sessions). The training intensity was progressively increased from 65% to 85% of heart rate with control by a POLAR FT7 heart rate monitor for aerobic activities, and by 8-15 repetitions in 2-3 sets for the strength activities. Exercise intensity was prescribed using Karvonen equation.

Every supervised session had the same structure and a duration of 60 minutes. American College Sport Medicine (ACSM) Guidelines for Cancer Patients were followed for the session design. The first 10 minutes was a dynamic warm up combining different ways of movement around the class and articular movements. Next part consisted in aerobic exercise, where the principal aim was to practice exercises that increased the participant's functional capacity with music-based activities such as aerobic, box-dance or global strength circuits without external resistance. Followed by upper-limbs strength exercises with elastic bands to improve strength and increase arm lean mass, focusing on chest and dorsal exercises. The last part was whole-body stretching exercises to improve joint mobility and muscle flexibility of upper body limbs, and general muscle relaxation after training.

The exercise program was complemented with theoretical classes about exercise and nutrition. One class of exercise prescription was held after two months of intervention. The patients were taught about the minimum of exercise recommended and about which activities they could do and how to adapt them depending on their own situations.

The nutrition program consisted of three theoretical and practice classes, where specific terms of nutrition and diet were explained. The first class explained the different groups of nutrients, their functions in the organism and for which group of aliments these can be obtained. The second class was a practical class about how to interpret food labels and relating measurements of food portions with recommendations for a healthy diet. Final session spoke about the ten best and the ten worst aliments, which prevent and promote cancer. Teachers did not promote avoiding any group of aliments and a Mediterranean diet was encouraged to be followed.

Inclusion Criteria:

Inclusion criteria:

• Older than 18 years and younger than 75.
• Breast cancer diagnosed confirmed stage I-IIIA.
• Randomized disposition.
• Minimum of 45 days and maximum of 36 months after finishing treatments (chemotherapy and radiotherapy).
• 0-1 in Eastern Cooperative Oncology Group (ECOG) scale (present the ability to walk briskly)
• Oncologist approval.
• Informed Consent signed.
• Comunidad Autónoma de Madrid inhabitant.

Exclusion Criteria:

• Metastasis presence
• Serious medical risk such as unstable cardiac condition or severe pulmonary disease and anticoagulants treatments.
• Oncology or primary care approval who verified the medical risk exclusion criteria.
• ECOG > 1
• Pregnant