The primary purpose of this pilot study is to determine whether breast cancer patients whom elect to undergo cardiotoxic neoadjuvant chemotherapy can be enrolled and retained in a 6 month at home aerobic exercise training study. Using a randomized controlled trial approach, we will examine the safety and efficacy of a well monitored moderate-to-high intensity aerobic training program completed at home in breast cancer patients receiving neoadjuvant chemotherapy. In addition to assessing safety and efficacy of the program, we will assess intervention effects on cardiopulmonary fitness, cardiac function, and tumor response.