These are not your usual "staying fit" runners or the people you see running 5ks/10ks/half marathons or even the one-time bucket list marathon.

These people were high-volume competitive repeat marathoners and ultramarathoners, if you look at the study. These people are on the extreme end of running, especially the ultramarathoners...they're pushing themselves past the "wall" regularly (which is literally your body shutting down because you've pushed it so hard) and experience throwing up and diarrhea as a result of their training/races.

These are also the people in the running community who are most likely to be extremely underweight, which is associated with worse health outcomes than being a healthy weight.

https://www.inovanewsroom.org/press-release/2025/08/groundbreaking-inova-study-finds-potential-link-between-long-distance-running-and-colon-cancer/

Anonymous wrote:I wonder if this has to do with with all the processed energy products - GUs, gels, etc. Protein powders and bars just can't be good in the long term, too.

There's no replacement for real food.

Highly doubt that because the American diet is so full of processed foods that a runner consuming these products would still be unlikely to be exceeding average levels. It wouldn’t explain the elevated risk. More likely has to do with stress on the body. I also wonder about extended proximity to car exhaust with all the training. But wouldn’t that mean lung cancer?!

I wonder if this has to do with with all the processed energy products - GUs, gels, etc. Protein powders and bars just can't be good in the long term, too.

There's no replacement for real food.

Worry more about your anxiety disorder

Not at all. I'm a passionate runner since childhood and I am 56. I run half marathons, but never marathons or even longer distances. Running marathons and ultra marathons is an extreme sport, which, even without clinical studies, has never seemed healthy to me.

Just shorten your runs.

Anonymous wrote:They should be more worried about sunken face

that won't kill them.
PSA: get a colonoscopy!

They should be more worried about sunken face

Not even the tiniest bit concerned.

No, these are long distance runners and I haven't done more than 7.5 miles at once.

There was a prior thread on this topic:

https://www.dcurbanmom.com/jforum/posts/list/1288377.page

this study included people up to the age of 50 -- when 45 is the normal recommended screening age. If i had any concern at all, advocate to your doctor for an earlier colonoscopy. That's the "good" thing about colon cancer - it can be detected, often prevented, before it turns deadly.

Everyone should schedule their screening colonoscopy by the age of 45. Sooner if other factors apply.

Gift link to full article:

https://www.nytimes.com/2025/08/19/health/running-colon-cancer.html?unlocked_article_code=1.fU8.b8FQ.jBHul-4c3Pb6&smid=url-share

Get your colonoscopy. No one in this (tiny) study had cancer -- some had polyps that could become cancerous but were not yet. Keep on top of your preventative medical care is the best advice for runners and non-runners.

Apparently long distance runners are at a higher risk. It was a small study but still concerning.
https://www.nytimes.com/2025/08/19/health/running-colon-cancer.html