The Washington PostDemocracy Dies in Darkness

Runners raced through mud in California. Now some have rashes and fevers.

A group of contestants in athletic clothes covered in mud climb over a wall that is just taller than head height. A yellowing grass field can be seen in the foreground.
Participants in the Tough Mudder race climb over an obstacle at Sonoma Raceway in Sonoma, Calif. (KTVU Fox 2)
3 min

For hours, Noa Umbaugh and her five friends ran, crawled and dragged one another through a gritty obstacle course at the Sonoma Raceway in Sonoma, Calif. Tangles of barbed wire and rows of wooden boards forced them to submerge themselves in pits of muddy water.

It was all part of the appeal of the 10-kilometer race put on by Tough Mudder, a race organizer that boasts about the grimy challenge of its obstacle courses. Umbaugh and her friends celebrated after completing the course on Aug. 20. They washed off the mud and went home.

But the next morning, Umbaugh woke up and discovered a rash of painful red bumps covering her legs and stomach. They were sore and hot to the touch. Her friends had them, too. Her concerns grew when she found more stories on social media of other Tough Mudder participants coming down with similar symptoms.

“It was just disgusting,” Umbaugh, 26, told The Washington Post.

A doctor diagnosed Umbaugh with folliculitis, a skin infection sometimes caused by bacteria, and prescribed antibiotics. An announcement from the Sonoma County Department of Health Services later that week said she wasn’t alone: Multiple participants had reported rashes accompanied by fevers, muscle pain and vomiting after running the Tough Mudder race, it warned in a public health advisory.

Tough Mudder, the Sonoma Raceway and the Sonoma County Department of Health Services did not immediately respond to requests for comment Sunday evening.

Umbaugh was running her second Tough Mudder race after first completing a course the previous year, also at the Sonoma Raceway. The event, which featured several obstacle courses of different lengths over the weekend, felt like a fun challenge to her and her group of friends, an outdoorsy hiking group.

Nothing seemed amiss until the day after, when Umbaugh woke up with a rash. She feared that small cuts she had gotten on her knees while climbing around rocks on the obstacle course may have contributed to the infection.

“I looked in the mirror, and my entire knees were covered, my legs were covered, my stomach, too,” Umbaugh said. “It was like something I’ve never seen before.”

She quickly found that she wasn’t the only one. Increasingly alarmed posts on the Tough Mudder subreddit, a forum for the race’s participants, described runners visiting the emergency room and receiving diagnoses for bacterial infections. Umbaugh was prescribed antibiotics but did not get her condition tested to identify the bacteria responsible for her infection, she said.

A Sonoma County official said they have confirmed at least 15 cases of people experiencing symptoms after the race, the Santa Rosa Press Democrat reported Wednesday. Some participants exhibited symptoms consistent with a bacterial infection, and one patient tested positive for Aeromonas, a waterborne bacteria.

Tough Mudder acknowledged the reports of infections and said in a message to participants sent after the Sonoma County health alert that it was investigating the incident, Umbaugh said, but the company did not respond to her request for a refund for the race’s $150 entrance fee.

Umbaugh is concerned about whether organizers tested the site, which she said is grazed by animals. The Sonoma Raceway uses a herd of sheep to manage its grassland, according to the raceway’s website. Sonoma Raceway did not immediately respond to an inquiry about whether animals grazed the fields where the Tough Mudder races took place.

One week later, Umbaugh’s rash has lessened but not disappeared entirely, she said. She is considering checking with her doctor again.

She and her friends spent the week nervously updating each other on their symptoms. They will opt for a hike instead of a mud-soaked obstacle course the next time they get together.

“I wanted to try it out,” Umbaugh said. “But I’ll never do it again.”