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The Impact of Exercise on Cancer – A Guest Blog by Glenn Sabin

Updated: Nov 9, 2023

I spend more time at the gym and exercising than just about anyone I know. I’ve been working out for years — and became more dedicated after being diagnosed with cancer in 1991.

It’s a bit embarrassing, but let me come clean:

  1. I have zero athletic ability

  2. Outside of Boy Scouts softball 40+ years ago I have never been on an organized sports team

  3. I am not coordinated enough to do body pump and other cardio — I’ve got two left legs and am easily confused

  4. Group Pilates or Yoga is about as far as I go in terms of ‘coordinated movement with others’

  5. My extremely athletic sons get their innate ability from my wife or someone else on either side of the family

However, I get a shit-ton of physical activity because of the reasons elucidated in this piece. So please, read on…

On average I lift weights six days a week and log over 20 miles of rigorous walking. In inclement weather I do interval training indoors on the treadmill. A couple days a week I also squeeze in an hour of Pilates.

I’m not advocating anyone become the workhorse I am. It is incredibly difficult — and sometimes impossible — to move through pain and tiredness. That’s why those diagnosed with cancer, going through treatments, and recovering, tend to become less physically active. Yet, to move to the best of our ability in whatever creative and enjoyable ways fit our lifestyle can be transformative.

Even back in 2003, when I had an acute episode of raging leukemia — constant low-grade fever, night sweats, and anemia — I was working out. Daily.

During that challenging stretch it was short swims and walks; the weights were just too much. The cardio was of moderate intensity, at best, but tough and necessary for this n of 1. It absolutely kicked my ass, but in a satisfying way.

All this physical activity happened after my physicians warned me to stay indoors, out of the heat, and to take it easy. The thinking then was that bed rest was more appropriate than breast stroke.

My oncologist’s concern was that physical activity, together with anemia and fatigue, fueled by an acute leukemic episode, could strain my heart. It made sense, but I didn’t listen.

In n of 1 I write about escaping from the hospital and heading off campus for a couple hours one bright summer day. Tethered to an IV pole, I was on the move. Literally.

I knew what my body and mind needed: Fresh air and physical activity — as much as I could muster.

Coming off a nasty week cooped up in a hospital room, with an infectious disease team hovering over me to rule out something other than the underlying chronic lymphocytic leukemia (CLL), I was feeling depressed and isolated.

All that lying around compounded the negative noise and fear spinning in my head.

When I got home it was the same deal. Moping around, greeting an endless stream of well-intentioned visitors, and my wife, Linda, tending to me like Florence Nightingale.

As lousy as I felt, I knew laying low was just making me, psychologically and emotionally, sink further. So I decided to go outside on those hot July days. I’d grab my canine sidekick, Jazz, jump in my old convertible, crank the music, and beeline for the park.

Exercise and Chemicals

I’ve always leveraged exercise and all forms of physical activity for the natural pharmacopeia that it is. Serotonin, norepinephrine, dopamine, and endorphins are always available in my brain’s go-to medicine cabinet, accessible from wherever I choose to unleash them: The gym, park, beach, pool, back yard.

For decades, exercise has simply become part of my lifestyle. Moving daily makes me feel amazing — physically, emotionally, and psychologically. It gives me a sense of control and provides cognitive support.

And when I miss a day or three due to injury or being under the weather? Trust me — you will want to stay clear of this very grouchy man.

Old School Thinking

Not too long ago, physicians would tell patients with bad backs and other joint issues to rest a lot, and to reduce their physical activity. Remember when traction was once very popular for those with herniated disks, sciatica, and other conditions?

That thinking shifted in recent times to more of a ‘use it or lose it’ philosophy, where limited physical activity is linked to worsening pain and muscle and joint atrophy — and more activity seems to keep joints lubricated, helping keep aches, pains, and arthritis at bay.

The less-is-more-take-it-easy mindset for cancer patients, and survivors, followed this same thinking for years: Those undergoing treatment (or in recovery) and dealing with fatigue, nausea, and pain should pace themselves.

However, this has proved to be a wasted healing opportunity. The emerging science is showing exercise as a powerful tool to prevent cancer, for helping to mitigate the often deleterious side effects of active treatment, and for contributing toward long-term survival.

Exercise and Cancer Risk — What Does the Science Say?

The answer is not definitive, but according to the National Cancer Institute:

There are a number of mechanisms through which physical activity could affect [positively influence] cancer risk [vis-à-vis prevention and survival]. It has been hypothesized that cancer growth could be initiated or abetted by three metabolic pathways that are also affected by exercise: sex steroids (estrogens and androgens); insulin and insulin-like growth factors; and proteins involved with both insulin metabolism and inflammation. Additionally, several non-hormonal mechanisms have been hypothesized to link physical activity to cancer risk, including inflammation, immune function, oxidative stress, and, for colon cancer, a reduction in time that it takes for waste to pass through the gastrointestinal tract.

Exercise and Cancer Prevention

In 2016, JAMA Internal Medicine published a study on ‘leisure-time physical activity’ and its impact in lowering the risk of 13 types of cancer.

This study pooled data on 1.44 million people, ages 19 to 98, from the U.S. and Europe, and examined an extensive range of cancers. Participants were followed for a median of 11 years during which 187,000 new cases of cancer occurred.

Those ‘leisure-time physical activities’ included walking, running, swimming. Other moderate to vigorous forms of exercise were also included. The median level of activity in the study was approximately two-and-a-half hours a week, pretty close to the current recommended minimum level of physical activity for the U.S. population.

Confirmation arrived — assessed by self-reported surveys — that indeed, leisure-time physical activity was associated with a lower risk of colon, breast, and endometrial cancers. As well, it was determined that leisure-time physical activity was associated with a lower risk of an additional ten types of cancers.

The greatest risk reductions were for esophageal adenocarcinoma, liver cancer, cancer of the gastric cardia, kidney cancer, and myeloid leukemia. Even myeloma and cancers of the head and neck, rectum, and bladder showed significant risk reduction (not as strong as the other results, but noteworthy nonetheless).

[NCI’s Cancer Physical Activity Fact Sheet can be found here.]

Exercise During Cancer Treatment/Long-Term Survival

I recently came across an excellent article in the journal Oncology, titled ‘Initiating Exercise Interventions to Promote Wellness in Cancer Patients and Survivors’.

For patients undergoing conventional cancer treatment, exercise has been shown to reduce levels of fatigue, depression, pain, and anxiety, while increasing quality of life, physical function, improving sleep, balance, and promoting healthier ratios of lean body mass to fat mass.

The Oncology article reviews current research on exercise in cancer settings and discusses the American College of Sports Medicine’s exercise recommendations for cancer survivors at various stages of cancer survivorship.

The authors make clear that an exercise program for those undergoing treatment and post-treatment should be tailored to the individual, keeping front of mind the common, acute, and long-term treatment side effects.

In Summary — Move Your Body

If you want to (1) increase your odds of preventing cancer; (2) get through active treatment in the best possible shape; (3) help ensure long-term survival post-treatment; and (4) improve your overall physical and emotional health — you should incorporate a lifelong exercise regimen tailored specifically for you.

You should absolutely consult your physician and get medical clearance before beginning any new exercise regimen.

Sadly, however, few physicians, including most conventional oncologists, are properly trained in this area. Oncologists are now aware of the link between obesity and various types of cancer — especially belly fat and breast cancer — but tend to have limited knowledge and experience in recommending specific exercises or physical activity protocols to patients.

This is where you come in as an empowered patient or survivor. Don’t get ‘stuck’ because of the unrealistic expectations you may have of your oncologist. It is incumbent upon you, and/or those supporting you, to seek out the very best professional guidance to creating a personalized exercise program for each stage of your treatment and recovery journey.

It is vital to find someone who has verifiable experience, certification, and success working with cancer survivors.

Meanwhile, you do not have to wait for more scientific studies. Just move your body. Daily. Starting today.

Did you know you can stay up to date with The Radical Remission Project through their monthly newsletter? Sign up for more healing stories as well as upcoming events and the latest news. Sign up HERE!


Glenn began his own, medically monitored and carefully researched lifestyle changes. He would conduct his own, informal, single patient clinical trial, through which he chronicled remarkable success.

A biopsy in 2012 confirmed that Glenn’s bone marrow contains no CLL cells. This Radical Remission was achieved without any conventional cancer treatment. His Harvard-documented case is part of the medical literature.

Today, Glenn is alive and thriving. He is a nationally recognized expert in integrative oncology, and an in-demand cancer coach, specializing in lifestyle changes to best prevent cancer, manage active disease, and to help ensure long-term survival.

Download an excerpt from Glenn’s book, n of 1.

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