Your Anti-Inflammatory Meds Are Secretly Hurting You

Instead of reaching for Advil in the middle of your race, one of the foremost experts on pain management during long-distance running has an alternative: blueberries.

David Nieman is a professor at Appalachian State University and the director of the Human Performance Lab at the North Carolina Research Campus. He’s pioneered the science of exercise and nutrition immunology and has published over 400 papers. But what does some scientist know about eating fruit, of all things, when your hamstring feels like it’s being fiddled by Satan?

Well, he’s run 58 marathons and ultramarathons—which is how he ended up studying long-distance runners.

“I was struck by how many [marathoners and ultrarunners] were so just sore afterwards,” Nieman said, “and I wondered what they were doing to cope with the pain.”

What he discovered by studying ultrarunners at the Western States 100 for five years was enough to concern him.

Seven out of every ten competitors took ibuprofen before and/or mid-race to reduce pain and swelling, Nieman and his team found. These runners not only experienced the same amount of muscle damage and soreness as those who didn’t take nonsteroidal anti-inflammatory meds (NSAIDs), but they also suffered from more endotoxemia (toxins in the bloodstream), systemic inflammation, and kidney dysfunction. In short, “It just made everything worse,” he said.

The Problem with Over-the-Counter Pain Killers

NSAIDs are anti-inflammatory agents that reduce pain, fever, and inflammation. They’re commonly called ibuprofen, with brand names Advil and Motrin, and naproxen, found in Aleve, and Aspirin. Voltaren (diclofenac), both in pill form and the popular gel, also fits in this category. They work by blocking prostaglandin production in the kidneys, which in turn shrinks blood vessels and decreases blood flow.

In a pharmaceuticalized world filled with a prescription for everything, these popular over-the-counter meds may sound pretty harmless. And in many cases, they are. But concerns about NSAIDs are not new in distance running. The biggest issue is their potential link to kidney dysfunction—limiting blood flow can strain the kidneys significantly. At worst, this leads to rhabdomyolysis, when muscle tissue breaks down and releases proteins into the bloodstream faster than the kidneys can clear them, causing the kidneys to shut down. Such severe renal failure is rare, but potentially life-threatening, and more likely when the renal system is already under duress during intense exercise, like running an ultra.

That’s why in 2021, the UTMB World Series banned the use of NSAIDs during and 24 hours prior to racing in its events, although it has since rolled that policy back to be in line with World Anti-Doping Agency (WADA) standards.

All Olympic sports, from archery to weightlifting, operate under the WADA code. For a substance to be banned by WADA, it must meet two of three criteria: provide or have the potential to provide a performance benefit, cause harm, and/or “violate the spirit of the sport.” As of now, WADA considers NSAIDs to be “performance-enabling” rather than “performance-enhancing.” But ultrarunning officials worry WADA may not be considering how point two—the ability to cause harm—applies to the unique demands of the sport.

Julien Chorier, the sports director for the UTMB World Series and an accomplished trail runner himself, admitted race officials are concerned about runners using certain painkillers during races, but remaining consistent with WADA is more important for now.

“For us it’s difficult,” Chorier said. “We want to be totally in line with WADA and have the same rules. We want one universal policy. But there is some movement on this. It’s important we keep discussing it.”

Why Runners Risk It

Despite warnings from many medical experts and scientists, studies suggest that NSAIDs are used by 30 to 80 percent of ultramarathoners, depending on the race. In one 2013 study on 32 ultramarathoners published in the British Journal of Sports Medicine, 44 percent said they used analgesics sometimes during training and racing to combat fatigue and pain. The majority of those medications were NSAIDs. A 2017 study on 89 ultrarunners conducted by physicians at Stanford University and published in the Emergency Medicine Journal found that figure to be more like 77 percent.

“They work well,” said Daniel Fitzpatrick, a sports physician in the U.K. who conducted a review of the risk of NSAIDs in the Journal of Science and Medicine in Sport.

It’s for this reason alone that many ultrarunners use NSAIDs during races—even when they know the risks.

Fitzpatrick believes the numbers may be even higher than the studies say due to self-reporting bias. One study, Fitzpatrick said, revealed that twice as many ultrarunners actually used them in a race. “The use of them is widespread,” he said.

Plus, there isn’t enough evidence to conclude that NSAIDs directly cause rhabdomyolysis, Fitzpatrick said. This was also the conclusion reached by Eve Pannone, a trail runner and doctor, in a 2024 systematic review published in BMJ Open Sport and Exercise Medicine, which she co-wrote with Rebecca Abbott.

Their analysis of 30 studies on the health risks of NSAIDs in marathon and ultramarathon running found there is “very little evidence” showing that NSAIDs harm the health of ultrarunners. However, anecdotal data may suggest otherwise; they conclude: “Indications from a few non-randomised studies of a possible effect on kidney function need exploring with more high-quality research.”

NSAIDs themselves may not cause acute damage, but they likely contribute to it. This is why NSAIDs are especially dangerous in the heat, when runners are likely dehydrated and nauseous: It makes a bad situation worse.

Meanwhile, Nieman found that ibuprofen can damage the lining of the gut just enough that it allows a tiny bit of bacteria to seep out into the bloodstream. It also seems to increase inflammation in some cases, another weird finding, given that ibuprofen is designed to reduce it. The study conducted by physicians at Stanford found that runners who took ibuprofen doubled their risk of injuring their kidneys, although it also found that nearly all of those cases resolve spontaneously.

These sometimes inconclusive, even paradoxical findings may be partly explained by the nature of the sport. Ultrarunners have a saying: It’s not if something will go wrong, it’s when.

These athletes run dozens of miles, generally in the heat, at altitude, or in bad weather, up and down mountains, all while attempting, sometimes miserably, to eat and drink enough to keep going. Dehydration is almost a given. It’s some of the most stress you can place on a body for that long a time without dying, unless you’re a prisoner of war, stranded in the desert, or training to be a Navy Seal. It’s hard, therefore, to know just how much damage is caused by NSAIDs and how much is caused by the race itself.

Given these confounding variables, Fitzpatrick drew one conclusion from the many studies he reviewed. NSAIDs themselves may not cause acute damage, but they likely contribute to it. This is why NSAIDs are especially dangerous in the heat, when runners are likely dehydrated and nauseous: It makes a bad situation worse.

“There’s no clear evidence that it will make you unwell,” Fitzpatrick said, “but we think that if you were to become unwell, it makes you a lot sicker, where you may even wind up in the medical tent.”

Is There a Place for NSAIDs in Your Training Regimen?

Despite the potential risks, Fitzpatrick doesn’t want to tell runners (or even his own athletes) to avoid NSAIDs altogether. Runners, instead, should avoid habits like taking them before a race or a hard workout. Only use them judiciously, he advised.

“We aren’t saying there’s no place for them,” he said. “But you should get out of the habit of taking them like you would a gel. If you know the race is going to hurt, then that’s not a good reason to use them.”

Pain is the body’s way of telling you when something is wrong. It’s true that both the body and brain can be pretty whiny, and it’s also true that runners have to expect some level of discomfort during a race, from 5Ks to 100 miles and beyond. But taking something to mask the body’s warning signs concerns Renee McGregor, a leading sports dietitian who worked with Olympic teams and as a team manager for the U.K. 24-hour national team. She does not allow athletes on that 24-hour team to take NSAIDs. She also doesn’t take them herself as a runner and ultramarathoner who runs races up to 50 miles.

“You need to feel and listen to your body,” she said. “If you run through an injury, you’ve put yourself in a massive hole. I don’t think any race is worth that personally.”

Professional ultrarunner and two-time U.S. Olympic marathon trials qualifier Tim Tollefson has avoided NSAIDs for most of his career because he once had black tar stools after taking them. “It kind of freaked me out,” he said. “I remember thinking, ‘This doesn’t seem right.’”

Tollefson has won some exclusive races, including the Javalina 100-miler and Lavaredo Ultra Trail 120K, and he’s podiumed twice at UTMB. He doesn’t like the risks of taking NSAIDs mid-race, or that they may negate the inflammatory response your body needs for training to work. He questions why any runner would take them, especially if they’re hurt.

“If you need them to get to the start of a race,” he said, “should you really be thinking about even starting?”

Anti-Inflammatory Drug Alternatives

As Nieman and others remind us, there are other over-the-counter pain killers out there, and some of them are even good for you.

Blueberries

Take blueberries, for instance. Once Nieman began to warn runners at Western States about the effects of painkillers, he was met with thanks but also more than a little consternation: Well, then, what are we supposed to use?

The question intrigued him. And after experimenting with many different substances—he’s also a pioneering researcher in nutrition immunology—he found blueberries.

“The one that jumped out in terms of fighting inflammation was blueberries,” Nieman said. “They are the ibuprofen substitute.”

There’s some context to his recommendation. For one, you have to eat a whole lot of them. And for another, you have to eat them for a while. In fact, Nieman says you should eat a cup of blueberries each day for two weeks before your race.

Maybe think of it as another way to taper.

“The unique part of this, though, is that it isn’t a pill,” Nieman said. “These aren’t drugs you can take quickly.”

Anthocyanin, a flavonoid antioxidant responsible for their deep blue color, helps combat inflammation, Nieman said, along with the berries’ polyphenols and phenolic acids. Alas, the effects also go away pretty quickly if you stop the blueberry regimen.

Here are some other ways you can combat pain during a race:

Acetaminophen and Paracetamol

The brand name is Tylenol or Panadol. Europe, Australia, and India call it paracetamol, and, because the U.S. has to be different about everything, including the metric system (unless we are talking race distances), we Americans call it acetaminophen.

This class of drugs is generally considered safe to use while running—as long as you stay within the recommended dose—because it’s metabolized by the liver rather than being processed by the kidneys.

Fuel Properly

McGregor, who wrote a guide to fueling for races in her book Fuel for Thought, believes food can be a painkiller. “There’s nothing worse than overreaching,” she said, something many ultrarunners do during a race, “and not having the energy to do it. You usually feel good after you’ve eaten something.”

She also recommends eating protein during a race, such as five to ten grams every two hours or 30 grams every six. “Often it’s the breakdown of muscle that’s causing pain,” she said.

Have a Good Attitude

Wallowing in your misery can increase your perception of the pain you feel during a race. Try to be positive and remind yourself that you chose to be here.

Caffeine

Caffeine, McGregor says, changes your perception of fatigue. Fatigue makes everything worse and can increase your perception of pain. So caffeine can make the pain feel less severe. Many studies back this up.

“You can be quite clever with caffeine,” McGregor said. “You can overdo it, too, but sometimes we use caffeine in a strategic way.”

Stretch

Cold stretching is bad for you, but stretching during a race can help, especially if you know of a stretch that can relieve a problem area.

Dissociation and Distraction Techniques

Tollefson uses these during his races. “The ability to control your own thoughts and mind is incredibly powerful,” he said.

Acceptance

Preparing your mind for the pain of a race and then answering that pain with a mantra is a good way to cope with it. In The Terrible and Wonderful Reasons Why I Run Long Distances, author Matthew Inman (The Oatmeal) presents a mantra this author has used with success: “This hurts, and it will continue to hurt, and that’s OK.”

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