• According to a new study published in the journal Cancer, the more aerobically fit you are, the less likely you are to develop lung and colorectal cancer.
  • People who were most fit were 77 percent less likely to get lung cancer and 61 percent less likely to get colorectal cancer compared to the least fit.
  • There is still a benefit to being moderately fit, but the more fit you are, the greater the reduction in cancer risk.

Being aerobically fit has been proven to offer a ton of benefits: It strengthens your bones, joints, and muscles; keeps your brain sharp; and helps prevent obesity, type 2 diabetes, and heart disease, to name a few.

Now, there’s additional proof that running regularly does wonders for your overall health—according to new research in the journal Cancer, it can help reduce your chances of certain kinds of cancer.

In the study, researchers looked at 49,143 patients between the ages of 40 and 70 who had an exercise stress test done within Detroit’s Henry Ford Health System from 1991 to 2009. The results of the exercise stress tests were measured in metabolic equivalents of task (METs), and researchers placed the patients into the following categories:

  • Those who achieved 6 METs or less (the equivalent of run-walking or running a 15-minute mile)
  • Those who achieved 6 to 9 METs (the equivalent of running anywhere from a 15-minute mile to an 11-minute mile)
  • Those who achieved 10 to 11 METs (the equivalent of running anywhere from a 10-minute mile to an 8-minute mile)
  • Those who achieved 12 METs or more (the equivalent of running a 7:30-minute mile or faster)

Their findings? After an eight-year followup period (where researchers checked cancer registries and the National Death Index), patients who achieved 12 METs or more were 77 percent less likely to get lung cancer and 61 percent less likely to get colorectal cancer compared to patients who achieved 6 METs or below.

Additionally, among patients who were actually diagnosed with lung cancer, those were the most fit (12 or more METs) were 44 percent less likely to die. And among patients diagnosed with colorectal cancer, those were the most fit were 89 percent less likely to die.

And according to study coauthor Catherine Handy Marshall, M.D., M.P.H., assistant professor of oncology at Johns Hopkins School of Medicine, there are still advantages to being moderately fit.

“There was a graded benefit, so that those who were moderately fit had moderate benefit and those who were even more fit and an even greater benefit when compared to those who were the least fit,” she told Runner’s World.

[Run faster, stronger, and longer with this 360-degree training program.]

While Handy Marshall and her colleagues aren’t 100 percent sure of the reason behind why being aerobically fit is linked to a decreased risk of cancer and cancer-related death, she says it’s an ongoing area of research. However, according to the National Cancer Institute, there could be a few factors at play. Those who are aerobically fit are less likely to be obese, have inflammation, and have a poor immune system—all things which can contribute to developing cancer.

The bottom line? Just keep running. Not only will it make you feel good, but it can help protect against life-threatening diseases, too.

Headshot of Danielle Zickl
Danielle Zickl
Senior Editor
Danielle Zickl for Runner's World and Bicycling.