Here’s How Much Physical Activity a Day Cuts Your Risk of Colon Cancer

Photo credit: pixdeluxe - Getty Images
Photo credit: pixdeluxe - Getty Images

From Bicycling

  • People who were active as an adolescent, and maintained that activity in adulthood, were 24 percent less likely to develop a precursor to colon cancer than those who were inactive, a recent study published in the British Journal of Cancer found.

  • Those who started exercising in adulthood reduced also saw a benefit, though it was not as significant: They reduced their risk by 9 percent compared to those who were inactive.


Think back to what you were doing as a teen. Were you getting out on the trails for a ride? Maybe sprinting back and forth on the soccer field?

How active you were then—and how you’ve maintained it now—is important when gauging your risk of colorectal cancer, a recent study suggests. Physical activity during adolescence can lower risk of the disease, and if you continue moderate, daily physical exercise well into adulthood, the results are particularly dramatic.

Published in the British Journal of Cancer, the research looked at data from the Nurses’ Health Study II, one of the largest investigations into major chronic disease risk. Researchers analyzed data on 28,250 women aged 25 to 42, examining the long-term effects of physical activity, nutrition, and hormones, among other health factors.

They found that those who reported at least an hour of physical activity per day from age 12 to 22 had reduced risk of adenoma—polyps considered a precursor of colorectal cancer—by 7 percent, compared to those with lower activity amounts. Physical activity that started in adulthood reduced risk by 9 percent.

But for those who started being active as teens and continued that hour-plus-daily activity streak? They had the biggest benefit of all: They reduced their adenoma risk by 24 percent.

The takeaway here is that there’s a cumulative effect of physical activity as you age, according to study co-author Leandro Rezende, D.Sc., Ph.D.(c), of the University of Sao Paulo in Brazil. Starting physical activity at any age is advantageous for numerous reasons, including better colorectal health, he told Runner’s World, and the longer you maintain that activity, the better off you’ll be.

“Physical activity reduces the risk of colon cancer by several biological mechanisms,” he said. “Weight management and control are likely the most important, because it impacts insulin resistance and inflammation that are involved in the promotion and progression of cancer.”

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Although this study didn’t look at whether activity intensity or frequency made a bigger difference, Rezende said previous studies have shown that moderate-to-vigorous activity is associated with lower bowel cancer risks, as well as lower risk for breast and endometrium cancers.

Plus, recent studies suggest you don’t need to get your exercise in big exercise blocks, or even in 10-minute-plus increments, as previously believed. Even small bursts of activity can add up.

“The more activity you get, especially if you do it every day, and at higher levels, the more of an impact on cancer prevention you’re likely to see,” said Rezende.

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