The benefits of exercise for disease prevention and recovery are bountiful. Exercise of all kinds is highly recommended, for example, to combat and even reverse cardiovascular disease and obesity. The evidence linking exercise to better survival for cancer patients and survivors has been telling us this for years. The American Cancer Society and the US Department of Health and Human Services provide concrete cancer risk reduction guidelines, specifically highlighting the benefits of exercise.  Their recommendation of 150-300 minutes of moderate-intensity aerobic activity per week provides substantial benefits addressing treatment side effects such as fatigue, anxiety, depression, bone and muscle loss and even improves recovery and mortality rates.
Until recently, few research studies have focused on the benefits of exercise as applied to cancer patients suffering from the common, yet bewildering, side effect of “chemo brain”, or “chemo fog”. Chemo brain is a term used to describe symptoms of mental fogginess, fatigue, and disequilibrium experienced among cancer patients and survivors. Changes in cognitive function can result from brain tumors, but “chemo brain” is used to describe symptoms experienced by patients who do not have cancer in the brain. As the name implies, the condition is most often associated with chemotherapy treatment.
By observing how other cancer treatment side effects are positively affected by exercise, the theory that physical activity would net similar positive results for chemo brain is an intriguing and logical one to explore. A new large-scale and well-constructed study has examined the association between physical activity, chemotherapy and cognition. The findings were unquestionably solid. Those who met the ACS exercise guidelines before, during and after chemo treatments had the best cognitive performance.
Survivors who were more physically active prior to treatments had the best cognitive performance across the treatment period and in the 6 months afterward. This suggests that an early side effect prevention strategy of prescribing exercise prior to treatment protocols could be very effective.
It is too early to understand how exercise may impact the speed of recovery, recurrence rates or mortality if and when it is regularly prescribed prior to treatment. However, what is encouraging at this point is the fact that more participants reported continuing regular exercise 6 months after completing chemotherapy than they reported doing before treatments. This suggests that people understand the importance of exercise as a crucial part of recovery.
What is considered exercise? The US Department of Health and Human Services recommends 150 minutes of moderate-intensity aerobic activity per week, and at least 2 days of muscle-strengthening activity per week. It should be noted that the US Department of Health and Human Services includes yoga in their definition of moderate-intensity aerobic exercise, depending on the style and intention of practice.
“Many different forms of yoga exist, and they range in intensity level from more meditative Hatha yoga to power yoga. For this reason, yoga may include time that would be characterized as light-intensity physical activity or as moderate-intensity physical activity. Yoga may also be considered both aerobic and muscle strengthening, depending on the type and the postures practiced.”
What is missing from the well-constructed research on chemo brain, and what has yet to be considered, is the type of exercise and the dosage that best manages this side effect. Many kinds of moderate-intensity exercise, like brisk walking, golf, tennis, biking or rowing, can be challenging for many physically, economically and environmentally. This reason makes a solid case for oncology yoga as the exercise prescription because it is adaptable, considerate of all body conditions and, with access to the internet, readily available. Likewise for dosage, yoga can adapt to where the survivor is physically, emotionally and geographically.
“While we don’t know how much activity is needed to improve cognitive functioning, doing something active is better than doing nothing, … It’s figuring out how to move more every day, even if you can’t hit those guideline recommendations.” Sheri J. Hartman, Ph.D., of the University of California San Diego.
Researchers are still trying to understand this side effect, as medicine offers no relief. This study is the first indication that a solution is possible and that it could be as easy as 3 yoga classes a week.
 Salerno, E. A. et al. Physical Activity Patterns and Relationships with Cognitive Function in Patients with Breast Cancer Before, During, and After Chemotherapy in a Prospective, Nationwide Study. Journal of Clinical Oncology [Internet]. August 18, 2021 [Cited October 12, 2021];39:29. 3283-3292.
 Department of Health and Human Services Physical Activity Guidelines for Americans, 2nd Edition. Accessible from: https://health.gov/sites/default/files/2019-09/Physical_Activity_Guidelines_2nd_edition.pdf