The primary objective of this study is to investigate the feasibility of a multimodal prehabilitation programme consisting of MIET during neoadjuvant intravenous chemotherapy infusion, HITT and strength training during the last six weeks prior to surgery, and optimising nutritional intake throughout the total preoperative period in patients with breast cancer with respect to recruitment, adherence, dropout, safety and acceptance. The secondary objective is to provide a preliminary evaluation of participant responses to a preoperative multimodal lifestyle intervention, on cardiorespiratory fitness, muscle strength, nutritional status, and fatigue in patients with breast cancer receiving neoadjuvant chemotherapy.