by Gabe Mirkin, M.D.
In October 2018 I reported on a huge study from the Cleveland Clinic that showed exercise reduced death rates from all causes during the 21-year study period and that those with the highest levels of fitness had the lowest death rates. Most dramatically, the study showed that a high level of fitness was more beneficial than not smoking.
Compared to people who did not exercise, those with the highest level of fitness were more than 80 percent less likely to die from any cause. Being unfit was a stronger predictor of risk of dying than smoking, having diabetes, or having plaques in the arteries leading to your heart.
The authors concluded that, “There was no upper limit of benefit of increased aerobic fitness” (JAMA Netw Open, Oct 19, 2018;1(6):e183605). This is the largest analysis of patients referred for exercise treadmill tests: 122,007 patients, with 13,636 deaths between 1991 and 2018. The authors quoted many other studies showing that the more fit you are, the less your chances of dying from heart attacks, high blood pressure, diabetes, strokes, and cancer.
I had many questions about this report from cancer patients and cancer survivors, asking how this could be possible when we know that smoking increases risk for so many types of cancers. The Cleveland Clinic study did not analyze specific causes of death, but its findings support many other studies showing benefits from exercise during cancer treatment, for reducing risk of cancer recurrence, and for preventing many types of cancers.
Fitness Helps to Treat Many Types of Cancer
Exercise is now recommended as part of the treatment for cancer by the American College of Sports Medicine, American Society of Clinical Oncology, National Comprehensive Cancer Network, American Cancer Society, Oncology Nursing Society, the Commission on Cancer, and the Cancer Foundation For Life.
A regular exercise program reduces carcinogenic inflammation, strengthens the immune system, and improves mental processing by lowering cancer-inducing insulin-like growth factor 1, DNA damage and gene mutations, and increasing apoptosis (Exp Biol Med (Maywood), Feb 2013;27:585-6 and Br J Cancer, 2011;105:S52-73).
An extensive review of research (Translational Journal of the American College of Sports Medicine, December 1, 2016;1(17):152-158) shows that exercise:
• reduces the side effects of chemotherapy treatments including nausea, fatigue, anxiety, and depression and increases bone strength and muscle mass (Curr Treat Options Oncol, 2008;9:135-46).
• increases the percentage of people who are able to complete full-dose chemotherapy regimens (J Clin Oncol, 2007;25:4396-404).
• can increase tumor sensitivity to chemotherapy (Cancer Prev Res (Phila), 2013;6:925-37).
• reduces heart damage from chemotherapy (Circulation, 2011;124:642-50).
• markedly reduces arm swelling from extensive breast cancer surgery (N Engl J Med, 2009;361:664-73).
• is associated with a 50 percent increased survival rate in patients treated for breast cancer (JAMA, 2005;393:2479-86) and colon cancer (J Clin Oncol, 2006;24:3535-41).
• is associated with a 70 percent risk reduction in high-grade, advanced, or fatal prostate cancers (Arch Intern Med, 2005;165:1005-10).
Fitness Helps to Prevent Deaths from Cancer
A review of 12 prospective US and European studies on risk for 26 types of cancer in 1.44 million adults followed for 11 years showed that exercise is associated with reduced risks for cancer, regardless of body size or smoking history (JAMA Intern Med, published online May 16, 2016). Leisure-time physical activity was associated with a lower risk of cancers of the colon, breast, endometrium, esophagus, adenocarcinoma, liver, stomach, kidney, head, neck, rectum, bladder and lung and myeloid leukemia and myeloma.
Heart-lung fitness was measured by the maximum amount of oxygen that 5131 Danish men could take in and use (VO2max). They were followed for 44 years, and 1527 (29.8 percent) developed cancers. The higher their fitness levels, the less likely they were to develop cancers (Br J Sports Med, 2017 Sep;51(18):1364-1369).
Heart-lung fitness was measured by incremental exercise testing in 13,949 men, and the fitter they were, the less likely they were to suffer deaths from cancers of the lung, colon and rectum (JAMA Oncol, May 2015;1(2):231-7).
A Fitness Program for Cancer Patients
The FitSTEPS for Life (FSFL) program was started in 2001 as an evidence-based cancer rehabilitation program that charges no fees, is community-based, and is offered to cancer survivors from diagnosis onward. In the last 12 years, more than 14,000 referred patients have attended more than 350,000 exercise sessions at 13 community-based locations. To be accepted by FSFL, a cancer patient must be referred by a physician with specific recommendations on the patient’s limits for safe exercising.
Tips on Exercise for Cancer Patients
If you do not already have a regular exercise program, check with your doctor as soon as possible. After your doctor approves exercise for you, try to get into an exercise program that caters to people who are starting out at your level of fitness. I cannot recommend a specific exercise program for cancer patients because the amount of exercise you can do is limited by level of fitness and extent of disease. I can tell you that all exercisers, healthy or not, should follow these rules:
• Take the day off when your muscles feel tight or hurt after you have warmed up for five or more minutes. It is normal for muscles to feel sore when you first get up in the morning, but they should feel better after you have exercised for five to 10 minutes. Soreness after warming up means that your muscle fibers are damaged and are at increased risk for tearing if you exercise that day. Sometimes you can get away with exercising at reduced intensity on days when your muscles feel sore.
• Stop exercising immediately when you feel increasing soreness in one spot. That means that your muscles are about to go into a spasm and tear. You can prevent many injuries just by stopping exercising when you feel pain in one spot and not in the same spot on the other side of your body.
• Slow down if your muscles start to feel tight, hurt or burn. If the discomfort goes away in a short time, you can pick up the pace again, but if it continues, stop for the day. As you keep on exercising, your muscle fibers start to tear and run out of their stored sugar supply.
Your body always talks to you and tells when this is happening to you. Failure to listen to your body is the most common cause of exercise injuries.