Disclaimer: This blog is not a replacement for medical advice from your oncologist. Talk to your doctor before changing any part of your treatment plan to ensure it is safe for you.
It seems like you can’t go a day on social media without seeing a post or meme talking about how exercise is a cure-all. But sometimes it’s a little more complicated. For example, does exercise help you age slower, or can it actually age you faster?
As with most things, the real answer is more nuanced and not universal. Not every person or situation is same.
If you have seen my TEDx talk or listened to my podcast, you know that I like to start any discussion on cancer treatment with a reminder that cancer is not a homogeneous disease. By this I mean that all cancers are different. This is not just the idea that brain cancers are genetically and metabolically different from breast cancers; but even within a single tumour the cells that make it up can be quite different from one another.
What you should take away from this fact is that what works for treating one cancer may not be effective for all cancers or specifically your cancer. You should discuss all treatment options and changes to your treatment plan with your oncologist before starting something new.
That being said, what does the research say about exercising with cancer?
Exercising with cancer
In the last decade there have been many studies related to exercise and cancer. Many of them show some really interesting results. Unfortunately, none of these studies show that exercise will cure your cancer, but there are lots of great reasons that you should talk to your doctor and cancer care team about adding exercise into your treatment plan.
Exercise helps patients tolerate treatments & minimize the physical declines of cancer
Cancer and cancer treatment can have some devastating effects on the body. Decreased energy and general declining physical condition is almost universal for patients undergoing surgery and chemotherapy.
Research from the University of Alberta looked at how adding aerobic and resistance exercise to breast cancer patients receiving chemotherapy could decrease the negative effects of treatment and improve quality of life.
Aerobic means “with oxygen”. In relation to exercise this doesn’t mean breathing or not breathing, but whether or not your cells generating energy in a way that that requires oxygen or not. Types of aerobic exercise are traditionally things like the use of cardio machines, spinning, running and swimming. Resistance exercises, or anaerobic “without oxygen” exercises, on the other hand include things like free weights, resistance bands and use of weight machines.
While neither aerobic nor resistance exercise were found to significantly improve cancer-specific quality of life in breast cancer patients receiving chemotherapy, they did improve self-esteem, physical fitness, body composition and chemotherapy completion rate. Allowing more patients to complete treatment is an important step in successful therapy.
A separate meta-analysis conducted by the Australian Catholic University looked at seventy-nine studies that involved exercise as an intervention for cancer. A total of 36 exercise studies tested aerobic modes of exercise, 13 tested anaerobic modes, and 20 tested a combination of aerobic and anaerobic modes. An additional 10 studies looked at a combination of exercise plus psychological intervention. The authors of the meta-analysis were able to make the conclusion that adding exercise to traditional cancer therapy could allow patients to experience fewer/less severe adverse effects of treatment. This result was seen across all four intervention types, roughly equally for exercise, psychological and exercise plus psychological interventions. Exercise even outperformed the benefits of pharmaceutical interventions alone for decreasing adverse effects of treatment.
One of the most common adverse events experienced by patients with cancer, both during and after therapy, is cancer-related fatigue. A meta-analysis conducted at University of Rochester Medical Center found that exercise and psychological interventions are effective for reducing cancer-related fatigue and demonstrated the usefulness of adding exercise to treatment regimes.
Mental distress and improving quality of life with cancer
Another terrible common side effect of cancer and treatment is depression. Exercise has, in the non-cancer population, been shown to be an effective antidepressant for some patients. Following this same idea, Northwestern University conducted a meta-analysis looking at cancer survivors and whether exercise could be used to help those battling this set of diseases. They found modest benefits in terms of reduced depressive symptoms when patients exercised in large groups that were either supervised or partially supervised. It should be noted that exercise unsupervised conducted at home had no benefit.
Why did the supervised exercise have a benefit when the at home workouts did not? It isn’t entirely clear and would need a seperate study looking specifically at that to determine the cause, but we can look at some of the differences and make an educated guess. For starters, in a supervised environment the exercises can be done with proper form and less likely to cause injury. But more likely, the group programs forced both an additional level of social interaction to the patients who might otherwise stay indoors at home for their treatment which can also help with these symptoms, and allowed the patients to be seen more regularly by health care providers who supervised these groups. More contact with health care providers means more care overall.
Another meta-analysis conducted at University of New Mexico looked specifically at how interventions with exercise could affect health-related quality of life and found it had benefit across several cancers.
For breast cancer, the authors found greater reduction in anxiety for survivors. In prostate, gynaecological, and lymphoma patients they found great improvements in depression, fatigue, sleep disturbances and emotional well-being. The study does mention that all of the trials they looked at were at high risk for what is called “performance bias“. This happens when one group or groups in a study get a greater amount of attention or care, and it can’t be precisely determined whether the treatment is having the effect or if the increased attention and overall care is having that effect.
The authors also point out that the studies had a few other limitations. The first was that the people enrolled in the studies might not have been completely random or representative of portions of the regular population. Imagine studying heart disease risk only in teenagers, and then making claims about that study for all of America for example.
The second limitation was that many of the studies lost people from one treatment group more than from another group. This is called attrition bias, and when looking only at the final outcomes of a treatment, it can make you ignore the reasons why so many people left a group or could not continue treatment. Especially if the treatment itself is having that adverse effect.
Lastly, is something called detection bias. This is something you should keep in mind anytime you see testimonials for wired products on Facebook too. For many of these studies what it means is that because the participants knew both if they were or weren’t receiving the additional exerise intervention, and they knew exactly what the researchers were looking for in the outcomes (less fatigue, etc.), the self reporting survey results can affected if participants felt they should be feeling something or not.
Is exercise recommended for cancer treatment?
Based on decades of research and the meta-analyses I’ve discussed above, both the American Cancer Society and the Cancer Council of Australia recommend adding exercise to cancer treatment plans.
Exercise can aid in managing the common side effects of treatment and allow patients to speed up their return to usual activities and improve their quality of life. It can keep muscles from wasting due to inactivity, decrease risk of heart disease, help control your weight, and boost self-esteem.
You should always speak with your doctor before starting a new exercise program with cancer to ensure you don’t push yourself too hard. But most patients should be able to benefit from the addition of some sort of supervised exercise program. Your doctor can ensure what’s safe and what will work best for you, especially if you are undergoing chemotherapy or recent surgery to allow adequate time for recovery and healing.
As always, thank you for allowing me on your cancer journey and sharing the latest research with you. It is through research and knowledge that we will be triumph over this set of diseases.
