Trial Comparing the Effects of Linear Versus Nonlinear Aerobic Training in Women With Operable Breast Cancer

Inclusion Criteria:

* Aged 45-80 years
* Female
* Has been diagnosed with early-stage breast cancer
* Post-menopausal, defined as :
* Age ≥ 45 with no menses for at least 2 years
* Chemically induced menopause through ovarian suppression, as determined by the primary oncologist
* An interval of at least one year, but no more than five years, following the full completion of primary therapy for malignant disease. Primary therapy is defined as:

  * Surgery plus radiation
  * Surgery plus chemotherapy
  * Surgery plus trastuzumab
  * Surgery plus hormone therapy Note: For patients who receive hormone therapy following surgery, the definition of one-year post-completion of therapy is defined by the surgery date. Patients who are currently receiving hormone therapy are eligible for enrollment.
* Weight of \< 205 kgs
* ECOG status of 0 or 1
* Life expectancy ≥ 6 months
* Performing less than 150 minutes of structured moderate-intensity or strenuous intensity exercise per week.
* Exercise intolerance defined by a VO2peak below that predicted for sedentary age and sex-matched individuals as defined in Appendix H.
* Willing to be randomized to one of the study arms
* Able to complete an acceptable baseline CPET, in the absence of high risk ECG findings or other inappropriate response to exercise as determined by the investigator.
* Able to achieve an acceptable peak baseline CPET, as defined by any of the following criteria:

  * Achieving a plateau in oxygen consumption, concurrent with an increase in power output;
  * A respiratory exchange ratio ≥ 1.10;
  * Attainment of maximal predicted heart rate (HRmax) (i.e., within 10 bpm of age-predicted HRmax \[HRmax = 220-Age\[years\]);
  * Volitional exhaustion, as measured by a rating of perceived exertion (RPE) ≥ 18 on the BORG scale.

Exclusion Criteria:

* Any of the following absolute contraindications to cardiopulmonary exercise testing:

  * Acute myocardial infarction within 3-5 days of any planned study procedures;
  * Unstable angina;
  * Uncontrolled arrhythmia causing symptoms or hemodynamic compromise;
  * Recurrent syncope;
  * Active endocarditis;
  * Acute myocarditis or pericarditis;
  * Symptomatic severe aortic stenosis;
  * Uncontrolled heart failure;
  * Acute pulmonary embolus or pulmonary infarction within 3 months of any planned study procedures
  * Thrombosis of lower extremities;
  * Suspected dissecting aneurysm;
  * Uncontrolled asthma;
  * Pulmonary edema;
  * Respiratory failure;
  * Acute non-cardiopulmonary disorders that may affect exercise performance or be aggravated by exercise (i.e., infection, renal failure, thyrotoxicosis);
* Presence of any other concurrent, actively treated malignancy
* History of any other malignancy treated within the past 3 years (other than non-melanoma skin cancer)
* Presence of metastatic disease
* Room air desaturation at rest ≤ 85%
* Mental impairment leading to inability to cooperate
* Any other condition or intercurrent illness that, in the opinion of the investigator, makes the participant a poor candidate for the trial