By Jonathon Stavres MS, ACSM-EP-C
Breast cancer affected nearly 231,000 women in the United States in 2013, and 40,860 of those women eventually died from the disease (CDC, 2013). Due to the significant impact of this disease, there is a very large base of research focusing on the possible benefits of exercise for those dealing with, recovering from, or at high risk for developing breast cancer.
Regular exercise and fatigue
One problem that research has tried to address is the cancer treatment related fatigue, a condition where cancer therapy causes significant fatigue and effects quality of life.
A study by Yang et al.(2015) examined the effect of a regular aerobic exercise program on fatigue in a group of women undergoing radiotherapy. All of the women had early-stage breast cancer; fatigue was assessed before and each week for six weeks during radiotherapy.
Results indicated that fatigue severity decreased significantly over time due to aerobic training, whereas fatigue severity increased in a group of women undergoing radiotherapy who did not participate in aerobic training.
Exercise and Estrogen Relationship
Another focus of research is on the prevention of breast cancer for women who are considered at high-risk. One aspect of prevention is estrogen-exposure. Estrogen is a female reproductive hormone that may influence the growth of breast cancer, and limiting estrogen exposure may mitigate breast cancer risk.
A study by Schmitz et al. (2015) tested the effects of aerobic exercise on estrogen secretion and found that regular aerobic exercise through five menstrual cycles reduced the estrogen exposure during the follicular phase of the menstrual cycle (every 100 minutes of exercise was associated with a 3.6% reduction in urinary estrogen).
These results suggest that regular aerobic exercise may help to limit estrogen exposure, however, these results need to be expanded on and more research needs to be done to better understand the exercise-estrogen relationship.
Take the necessary precautions
Although research does suggest that light-moderate intensity aerobic exercise can be beneficial for women dealing with breast cancer or at risk for breast cancer, there are some considerations to keep in mind.
As with anyone, acute high-intensity exercise does create a period of impaired immune function, which should be avoided. Similarly, overtraining (repeated very high intensity exercise sessions with little time for recovery) can result in tissue damage and overall impaired immune function in a healthy individual.
Therefore, it is very important to talk with your physician and an exercise professional before beginning an exercise program; both for safety reasons, and to design a program that is most effective.
*For more examples of other variations/exercises look under Multimedia-VDF Exercise Tips
**Consult with a physician and/or medical healthcare provider before starting any exercise regimen
Centers for Disease Control and Prevention. (2013). Breast Cancer Statistics.
Schmitz, K. H., Williams, N. I., Kontos, D., Domchek, S., Morales, K. H., Hwang, W. T., . . . Good, J. (2015). Dose-response effects of aerobic exercise on estrogen among women at high risk for breast cancer: a randomized controlled trial. Breast Cancer Res Treat, 154(2), 309-318. doi: 10.1007/s10549-015-3604-z
Yang, T. Y., Chen, M. L., & Li, C. C. (2015). Effects of an aerobic exercise programme on fatigue for patients with breast cancer undergoing radiotherapy. J Clin Nurs, 24(1-2), 202-211. doi: 10.1111/jocn.12672