Inclusion Criteria:  Newly diagnosed with stage I-III breast cancer, histologically confirmed. Patients scheduled to receive adjuvant post-operative chemotherapy. Partial or total mastectomy with axillary node dissection. Partial or total mastectomy with sentinel node dissection with body mass index between 30.0 and 39.9 kg/m2. Approval of their treating physician to participate in sub-maximal physiological fitness testing and a low to moderate progressive resistance exercise program.  Exclusion Criteria:  Inter-limb volume difference greater than 200 ml or 10%. Previous antineoplastic treatment (chemotherapy, radiotherapy, or endocrine therapy). Breast cancer stage IV Unable to participate in an exercise program related to other medical problems. Be identified as vigorous exercise behavior related to American College of Sports Medicine recommendations. Body mass index lower than 18.5 kg/m2 or greater than 40 kg/m2. Pregnancy. Fluency and understanding of the Spanish language.