Effects of Aerobic Exercise Versus Weight Training in Breast Cancer Survivors During Chemotherapy

The study was a prospective, three-armed, randomized controlled trial. Participants were stratified by site (Edmonton, Ottawa, and Vancouver) and planned chemotherapy protocol (taxane-based versus nontaxane-based) and randomly assigned to AET, RET, or usual care (UC) in a 1:1:1 ratio using a random-numbers table. Participants assigned to the AET group were asked to perform aerobic exercise three times per week on a recumbent or upright cycle ergometer, treadmill, or elliptical. Exercise duration began at 15 minutes for weeks 0 through 2, and then systematically increased by 5 minutes every three weeks thereafter to 45 minutes for weeks 18 and beyond. Exercise intensity began at 60% of VO2max for weeks 0 through 2 and then systematically increased by 10% every 6 weeks thereafter to 80% of VO2max for weeks 12 and beyond. Warm-up and cool-down periods consisted of 5 minutes of aerobic activity at the power output of the ventilatory equivalent for oxygen (approximately 50% of peak oxygen consumption). Participants assigned to the RET group were asked to perform resistance exercise three times per week, which consisted of two sets of 10 repetitions of 9 different exercises performed at 60-70% of 1-repetition maximum. The specific exercises were: leg extension, leg curl, calf raises, chest press, latissimus pulldown, overhead press, triceps extension, biceps curls, and modified curl-ups. Resistance was increased by approximately 10% or the next weight level when the participant was able to complete 12 repetitions per set without difficulty.

Inclusion criteria

• Breast cancer early stage I -IIIA
• Completed axillary surgery
• Scheduled to receive adjuvant chemotherapy for 9 - 24 weeks
• Approval of the treating oncologist
• Able to understand and provide written informed consent in English or French (Ottawa)
• 18+ years of age
• No uncontrolled hypertension, cardiac illness, psychiatric condition
• No contraindication to exercise as determined by a fitness test

Exclusion criteria

• Pregnant.
• Unwilling to accept randomization.
• Any medical condition that would be a contraindication to exercise. The clinicians will make this decision.
• Unwilling to travel to/participate in the exercise program as defined by the protocol.
• Previous chemotherapy (previous cancer is NOT an exclusion criteria).
• Cancer recurrence.
• Planned/known absence of greater than 2 weeks during the intended study period.
• Previous therapy for known breast cancer.
• Those who have had TRAM (i.e., Transabdominal Rectus Abdominus Muscle Reconstructive Surgery) done.
• Moderate lymphedema (>20% or >200mL difference between the affected arm and the unaffected arm).