Sitting More, Inactivity Linked to Worse Outcomes for Cancer Survivors

Sitting More, Inactivity Linked to Worse Outcomes for Cancer Survivors

Not exercising and lots of sitting can be harmful for cancer survivors.
Mar 25, 2022.

Cancer survivors who didn’t exercise and sat most of the day were more likely to die from cancer or another cause than those who sat less and were more active, according to a study.

The research was published in the March 2022 issue of the journal JAMA Oncology. Read the abstract of “Association of Daily Sitting Time and Leisure-Time Physical Activity With Survival Among US Cancer Survivors.”


About the study

Many studies have shown that exercise — before and after cancer — is linked to better survival for people diagnosed with several different types of cancer, including breast cancer.

Still, many people who’ve been diagnosed with cancer are quite sedentary. According to the National Cancer Institute (NCI), more than 33% of cancer survivors don’t exercise and spend many hours a day sitting or lying down.

In this study, the researchers wanted to know if a lack of exercise and prolonged sitting affected the survival outcomes of people who had been diagnosed with cancer.

The researchers used information from the U.S. National Center for Health Statistics’ National Health and Nutrition Examination Survey (NHANES) to identify a nationally representative sample of people diagnosed with cancer.

The NHANES collects health and nutrition information about people in the United States every two years.

The researchers did in-person interviews with the 1,535 cancer survivors in the study, as well as physical exams and lab tests. The people in the study also filled out questionnaires detailing their daily physical activity and how much time they spent sitting each day.

Of the people in the study:

  • 60.1% were female

  • 39.9% were male

  • 45.9% were ages 40 to 64

  • 54.1% were ages 65 and older

  • 83.1% were white

  • 7.8% were Black

  • 5.5% were Hispanic

  • 34.2% were considered overweight

  • 37.5% were considered obese

  • 21% had been diagnosed with diabetes

  • 21.7% had been diagnosed with heart disease

The researchers found that only 27.6% of the people in the study were physically active, meaning they did 150 minutes or more of physical activity a week. Nearly 57% of the people in the study were not physically active.

Most of the people in the study — 60.3% — said they sat for more than six hours a day. Almost 36% of the people in the study said they were not physically active and sat for more than six hours a day.

The researchers followed half the people in the study for less than nine years and the other half for longer periods of time.

During the researchers’ follow-up, 293 people in the study died:

  • 114 people died from cancer

  • 41 people died from heart disease

  • 138 people died from other causes

When the researchers looked only at the amount of time people spent sitting, they found that cancer survivors who sat the most each day were more likely to die from any cause.

Every additional hour people spent sitting each day made them:

  • 7% more likely to die from any cause

  • 9% more likely to die from cancer

  • 5% more likely to die from something other than cancer

People who did no exercise or did less than 150 minutes of exercise a week and who sat for more than eight hours a day were 5.38% more likely to die from any cause than people who exercised for at least 150 minutes a week.

Overall, people who exercised for 150 minutes or more a week were less likely to die from any cause than people who did no exercise and people who exercised less than 150 minutes a week.

“[The] combination of prolonged sitting with lack of physical activity was highly prevalent and was associated with the highest risks of death from all causes and cancer,” the researchers wrote.


ACS exercise guidelines for cancer survivors

As this study shows, exercise can have a big influence on outcomes after a cancer diagnosis.

In March 2022, the American Cancer Society (ACS) updated its Nutrition and Physical Activity Guideline for Cancer Survivors.

Besides survival benefits, exercise also can help reduce anxiety, depression, and fatigue; improve sleep and bone health; and ease side effects, such as joint pain and lymphedema.

If your doctor gives you the OK to exercise, you may want to try one of the following ACS guidelines on physical activity, which recommend:

  • 150 to 300 minutes a week of moderate-intensity exercise, meaning you can talk, but not sing, while you exercise (examples include brisk walking, yoga, and leisurely bicycling)

  • 75 to 150 minutes of vigorous-intensity exercise, meaning you have trouble talking or are out of breath while you exercise (examples include running, swimming, and singles tennis)

  • a combination of the two intensities

  • strength exercises two days a week (examples include hand weights; exercise bands; and body-weight exercises, such as push-ups or air squats)


What this means for you

This study reinforces the importance of exercise for people who’ve been diagnosed with cancer.

It also shows how bad sitting all day can be for you.

Still, we know that if you’re recovering from or still receiving breast cancer treatment — and are busy with work, household chores, and family matters — finding time to exercise almost every day can seem impossible.

It can help to break up exercise into 20- or 30-minute sessions that add up to at least 2.5 hours a week. Walking is a great way to start. You may want to try walking 15 minutes before going to work and 20 minutes on your lunch break. Many people walk a little extra by parking farther away from where they work or taking mass transit. It’s also a good idea to walk with a friend. People are more likely to stick with a routine when they exercise with a friend — plus, you can socialize at the same time.

No matter how old you are, it’s never too late to get moving. And once you start, keep at it!

Learn more about Exercise.

Written by: Jamie DePolo, senior editor

— Last updated on July 14, 2022, 4:34 PM

Reviewed by 1 medical adviser
Brian Wojciechowski, MD
Crozer Health System, Philadelphia area, PA
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