The study will include 76 participants aged 18-65 years, meeting specific criteria such as a diagnosis of hormone receptor-positive BC, no medical contraindications for exercise, no metastatic cancer, and no structured exercise in the last six months. These participants will be randomly assigned to a PE group or a control group. The study will consist of three phases: Phase 1 involves pre-intervention assessments, Phase 2 includes a 4-week PE intervention with three weekly sessions, and Phase 3 encompasses post-intervention and post-surgery assessments. The 4-week PE intervention in Phase 2 will include strength and aerobic training. Quality of life and fatigue assessments will use questionnaires, and measurements will be made for fat mass, lean mass, bone density, and cardiorespiratory fitness. Strength measurements will be taken, and shoulder mobility will be evaluated. Hemodynamics of the MT will be assessed using a hybrid device combining Near-Infrared Spectroscopy and Diffuse Correlation Spectroscopy with ultrasound. conditions: Breast Cancer studyType: INTERVENTIONAL phases: NA allocation: RANDOMIZED interventionModel: PARALLEL primaryPurpose: TREATMENT masking: NONE count: 76 type: ESTIMATED name: Prehabilitation exercise program measure: Quality of life score measure: Cancer quality of life score measure: Cancer-related fatigue measure: Body composition measure: Bone density measure: Cardiorespiratory fitness measure: Maximum isometric manual grip strength measure: Upper body maximum strength measure: Lower body maximum strength measure: Shoulder range of motion measure: Relative oxyhemoglobin concentration ([02Hb]) in the microenvironment of the tumor measure: Relative deoxyhemoglobin concentration ([HHb]) in the microenvironment of the tumor measure: Oxygen saturation (StO2) in the microenvironment of the tumor measure: Blood flow (BF) in the microenvironment of the tumor measure: Height measure: Body mass measure: Body mass index measure: Wait circumference measure: Anthropometric measurements measure: Bioimpedance measurements measure: Maximal heart rate sex: FEMALE minimumAge: 18 Years maximumAge: 65 Years stdAges: ADULT stdAges: OLDER_ADULT facility: Hospital Clínic status: RECRUITING city: Barcelona zip: 08036 country: Spain name: Eduard Mension, MD role: CONTACT email: mension@clinic.cat name: Albert Busquets, PhD role: PRINCIPAL_INVESTIGATOR name: Lucia Sagarra-Moreno, PhD role: PRINCIPAL_INVESTIGATOR name: Esther Valera, MSc role: SUB_INVESTIGATOR name: Graciela Martínez-Pallí, MD role: SUB_INVESTIGATOR name: Raquel Sebio, PhD role: SUB_INVESTIGATOR name: Blai Ferrer-Uris, PhD role: SUB_INVESTIGATOR name: Turgut Durduran, PhD role: SUB_INVESTIGATOR name: Mireia Mora, MD role: SUB_INVESTIGATOR name: Eduard Mension, MD role: SUB_INVESTIGATOR name: Helena Castillo, MD role: SUB_INVESTIGATOR name: Rosa Angulo-Barroso, PhD role: SUB_INVESTIGATOR name: Alfredo Irurtia, PhD role: SUB_INVESTIGATOR name: Marta Carrasco-Marginet, PhD role: SUB_INVESTIGATOR name: Alex Cebrián-Ponce, MSc role: SUB_INVESTIGATOR name: Ferran Faixat role: SUB_INVESTIGATOR name: Quim Rosales role: SUB_INVESTIGATOR name: Raquel Martinez-Reviejo, MSc role: SUB_INVESTIGATOR name: Paula Bonay, BS role: SUB_INVESTIGATOR lat: 41.38879 lon: 2.15899 hasResults: False