Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In


Trail Tips

Ultrarunning Hallucinations Happen. Here’s How to Deal With Them

Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.

For three-time Hardrock 100 finisher Steve Pero, the 2013 race was especially tough. He completed the iconic Colorado ultramarathon course in 44:39:48—hours slower than his two earlier finishes. His grumbling stomach prevented food from staying down, and his aging frame—he was then 61—felt the miles.

To make matters worse, there were the row houses lining the final miles of the Bear Creek Trail. Even in the middle of the night, families were out barbecuing on their decks, laughing and having a good time.

After the houses, he encountered a camper who had rudely set up his tent in the middle of the trail. A few yards later, Pero spotted hundreds of 1970s-style transistor radios, each hand-painted with pictographs of human faces and leaping animals.

Bizarre, absurd … and entirely nonexistent. Pero knew it, too. He was hallucinating.

Mind Games

Such experiences are not uncommon among ultrarunners. Andrew Mojica studied participants in Badwater, a 135-mile race through the heat of Death Valley, when he was a psychology student at the University of Texas at El Paso. “At least a third of ultrarunners I studied experienced hallucinations during their second night,” says Mojica, now a cognitive psychologist for the engineering and government-services company KBRwyle. “That number might be higher, too, as some participants may be forgetting what happened out there.”

If hallucinations seem like the mind playing tricks, the truth is, so is everything else you see. Vision is the result of a complex interplay between the eyes, the data-processing centers in the brain and possibly even our expectations and desires, according to Jay Sanguinetti, a research assistant professor at the University of New Mexico who studies psychophysiology, or how the mind and body interact.

“Your brain chooses what data from the optic nerve it wants to use,” Sanguinetti says. Conversely, it can create visual images that simply don’t exist. “Your brain has to assemble data into the best interpretation possible,” he says. To do that work, it combines two-dimensional visual information with a lifetime of experiences. “99.9 percent of the time, it’s right,” he says. That other 0.1 percent of the time, we see row houses.

Ultra Weird

This phenomenon happens much more often in the right circumstances. Running an ultra is one of those times—in fact, it’s just about perfect for creating hallucinations.

“It gets very complicated when it’s dark outside, or very shady,” says Sanguinetti, himself a trail runner who spent hours at a time running sections of the Appalachian Trail during college. The odds go farther south when you toss in sleep deprivation, which interrupts visual processing. Without the resources to get the job done, your eyes become a 1970s Radio Shack computer trying to load Microsoft Office: Error messages start flying.

Not all surreal occurrences are textbook hallucinations, however. If they last more than an instant or two, you might actually be dreaming, your brain switching between its dream and awake states. “It’s all blending together,” says Sanguinetti. “Your brain is saying, ‘This is the best I can do, given that you’ve been awake for two days while running. You’re going to see some stuff, and I’m not sure if it’s out there or in here, but at least you’re still moving forward.’”

That’s how Gary Robbins ended up seeing house numbers on trees during his 60-hour-long attempt to complete the notoriously challenging 100-mile Barkley Marathons in Tennessee this spring. Robbins also saw faces on leaves whenever he looked down. The visions lasted for hours, but Robbins—a top Canadian endurance runner who holds the fastest known time for the 93-mile Wonderland Trail around Mount Rainier and has completed a variety of ultras and multi-day adventure races—was experienced enough to know the routine.

“The first time, it’s like blistering or chafing,” he says. “It’s super painful. Then, you realize you’re not going to die. Years of experience definitely helped me handle hallucinating.”

Keeping It Real

Planning to run through the night, but want to avoid the flamethrower-toting gnomes? Mojica and Sanguinetti have a few suggestions.

Feed your brain. Relative to other organs in our body, our brains require a tremendous amount of oxygen and sugars to function properly. Deprive your brain of those resources, and it’ll start to go haywire.

Sleep when you can. Even with well-fueled brains, sleep deprivation will take its toll, guaranteed. As little as 20 minutes of snoozing at an aid station will help ward off hallucinations.

Avoid anticipating. Sanguinetti stresses the major role that “top-down” factors, or expectations and beliefs, play in shaping an outcome. “It’s like going into a house that you think is haunted—you expect to see ghosts, so you see ghosts. Then, you freak out and expend a lot of energy on being aroused.” Try not to go into races anticipating hallucinations.

Look assertively. As the miles pass, we have a tendency to shift to a more introspective mental state. The result? Less attention for the world around you, which may lead to more hallucinations. Try to focus on the trail aggressively.

Use a pacer. A pacer will help you engage with the world around you. He or she can also be vigilant, and point out when you’re hallucinating. The downside? Pacers can hallucinate, too.

Keep calm. If you do hallucinate, the best thing to do is to let it go. As when an unwanted thought intrudes on meditation practice, calmly acknowledge the hallucination without judging it. Don’t spend your precious remaining physical resources on it. “You’re in a really unusual situation, not faced by most of us,” says Mojica. “It’s fine. Try not to stigmatize it, and it should be less frightening.”

Doug Mayer would like to thank the pack of Labrador puppies that ran next to him in his last ultra. He lives in Randolph, New Hampshire, and is the founder of the trail-running tour company Run the Alps.