Why Young and Fit Athletes Must Take Colon Cancer Screening Seriously

John B. Johnson has always prided himself on maintaining a fit lifestyle. From running track in high school to playing rugby at Kent State University, physical fitness has been an integral part of his life. At the age of 35, he aimed to achieve peak fitness by training for the 2023 Cleveland Marathon, logging over 70 miles each week. However, one morning he noticed blood in his stool, initially attributing it to his consumption of beets. As the issue persisted, he recognized the importance of consulting a medical professional.

After successfully completing the marathon with a time of 3:04—qualifying him for the Boston Marathon—Johnson visited his doctor. Initially, the doctor suspected a ruptured hemorrhoid but proceeded to schedule a colonoscopy. The outcome of the procedure was alarming: a mass was discovered in his rectum, diagnosed as stage 2 colorectal cancer.

For Johnson, the diagnosis was utterly shocking. He led a healthy life, avoided processed foods, and had no family history of cancer. “I just secured my spot in Boston, and then I was told I was sick,” he recalls. “It made no sense.”

Rising Incidence Among Young Adults

Colorectal cancer is predominantly diagnosed in older adults, with the average age at diagnosis being 66. However, Johnson’s case is part of a troubling increase in colorectal cancer among individuals under the age of 50, many of whom lead otherwise healthy lives.

From 2013 to 2022, cases of colorectal cancer in adults younger than 50 increased by 3% annually. Studies, such as one published in the February 17, 2026 issue of JAMA, indicate that the death rate from colorectal cancer in this age group has risen by 1.1% each year since 2005. Colorectal cancer has now become the leading cause of cancer-related deaths in those under 50.

Colorectal cancer can begin in the colon or rectum, which, along with the anus, constitutes the large intestine. Early symptoms are often brushed aside or misconstrued, but common warning signs include altered bowel habits (such as unexpected diarrhea or constipation), rectal bleeding, and blood in the stool (either bright red or dark and tarry). Other symptoms may include rapid weight loss, fatigue, persistent cramping in the lower abdomen, and a sensation of incomplete bowel evacuation.

The Genetic Connection

Factors like excess weight, obesity, smoking, heavy alcohol consumption, and diets high in red and processed meats, alongside low fiber intake, significantly contribute to colorectal cancer risks. Additionally, conditions such as diabetes and inflammatory bowel diseases (like ulcerative colitis and Crohn’s disease) can elevate one’s risk profile.

Despite maintaining healthy lifestyle choices, an increasing number of individuals still receive colorectal cancer diagnoses. The reasons remain a matter of ongoing investigation.

Genetics might play a significant role in this trend. According to Dr. Vikram Reddy, MD, PhD, chief of colon and rectal surgery at Yale School of Medicine, individuals with a first-degree relative (parent or sibling) diagnosed with colorectal cancer face double the risk compared to those without such family history. The risk intensifies if the relative was diagnosed before the age of 50. Studies also suggest that the cancer risk may extend, albeit to a lesser extent, to second-degree relatives.

So far, genetic connections account for roughly 25% of cases, with inherited genetic conditions constituting about 10%. The remaining cases seem to occur sporadically.

“Genetics could be a significant factor in the rising cases among younger individuals, even those who seem healthy,” Dr. Reddy explains. “While we’ve identified several genes related to colorectal cancer, we still have much to learn.”

For those with a family history of colorectal cancer, genetic testing serves as an effective screening method. If individuals test positive for known genetic markers, they can initiate early screening protocols to monitor their health more closely.

Even those without a known genetic background should consider testing, as it can be life-saving. Tim Hill, a 36-year-old relief pitcher for the New York Yankees, learned this firsthand.

In 2015, he experienced unusual fatigue during spring training, prompting a blood test that revealed anemia—a potential indicator of colorectal cancer. Acknowledging that his father had died from the disease at 53, Hill was subsequently diagnosed with stage 3 cancer and discovered he had Lynch Syndrome, a hereditary condition responsible for many cases of colorectal cancer.

Following surgery to remove parts of his colon and extensive chemotherapy, Hill emerged cancer-free but considerably weakened. The path to recovery was certainly challenging, yet he ultimately reclaimed his health and vigor.

Hill’s journey highlights the necessity of being proactive regarding personal health and scrutinizing family medical histories. “My father likely developed cancer due to Lynch Syndrome, but he was unaware, so I never suspected I was at risk,” he noted, emphasizing the importance of awareness, even at a young age.

The Importance of Screening

Taking preventive measures against colorectal cancer is critical at any age. The first step is adhering to a healthy lifestyle. “If you focus on exercising, eating whole foods, opting for chicken and fish over red meat, and ensuring adequate fiber intake, you’re already on the right track,” states Dr. Reddy. “However, it’s crucial to remain vigilant and consult your doctor for persistent unexplained abdominal symptoms.”

Routine screening is vital as well. Colonoscopy remains the benchmark for colorectal cancer screening, and guidelines suggest that individuals begin screening by age 45. If there’s a family history of colorectal cancer, screening should start at 40 or ten years prior to the age at which the family member was diagnosed, whichever comes first. During a colonoscopy, a flexible tube equipped with a camera is inserted through the rectum to examine the large intestine for polyps—small growths that could evolve into cancer. Any detected polyps are removed during the procedure.

“Based on your results and risk factors, you might require colonoscopies every 10 years, five years, or even more frequently,” adds Dr. Reddy. “For individuals with genetic conditions, annual screening may be necessary.”

Inquiring about genetic testing can also be a prudent decision, especially if colorectal cancer has impacted your family. This straightforward blood test is relatively affordable and often covered by insurance when prescribed by a healthcare provider.

Resilience and Advocacy

For Johnson, battling colorectal cancer proved to be both painful and life-altering. After undergoing extensive radiation and chemotherapy, his tumor eventually disappeared. By 2025, he returned to the Boston Marathon, matching his previous time from the Cleveland Marathon. A month later, he ran the Cleveland Marathon again, surpassing the three-hour mark two years post-diagnosis.

Inspired by his experiences, Johnson established the Get Off My Butt Foundation to raise awareness about colorectal cancer among young adults and within the fitness community. His message is clear: never consider yourself invincible. “Recognizing something is amiss with your body and getting it checked is a testament to your strength, not a weakness,” he shares. “I was in excellent shape, and I still faced cancer. This underscores the truth that it can happen to anyone.”