The study will evaluate the utility of hypoxic exercise training to improve cardiovascular
and metabolic health among obese breast cancer survivors. While participants exercise, a
lower fraction of inspired oxygen will be used to simulate a higher altitude. This approach
removes the mechanical strain needed to sustain moderate-to-vigorous exercise intensity which
is believed to support exercise tolerance. Participants are randomized to either the
treatment (walking+simulated-altitude) or control (walking under normoxic conditions).