Photo: Paul Sakuma/Stanford School of Medicine

Ultrarunners May Want to Skip the Advil

A Stanford study finds that ibuprofen raises the risk of acute kidney injury.

By Diana Aguilera

If you’re an ultramarathon runner — one of those hardy souls unafraid to tackle a distance of 50 miles or more — you may want to reconsider popping pain pills like Skittles for your next race. Stanford University researchers recently found that endurance runners who took ibuprofen doubled their risk of acute kidney injury.

As many as 75 percent of ultramarathoners use the nonsteroidal anti-inflammatory drug to reduce pain and swelling, according to Grant Lipman, a clinical associate professor of medicine at Stanford and the lead author of the study. A long-distance runner himself, he was intrigued by how often people took ibuprofen before, during and after events.

“Running these races tends to hurt,” says Lipman, who directs the wilderness medicine section of Stanford’s emergency medicine department. Extreme athletes are already straining their kidneys through dehydration and muscle tissue breakdown. Adding ibuprofen into this mix further increases the danger of kidney damage.

Most previous studies of runners have not shown an association between NSAIDs and kidney injuries, Lipman says. This study, conducted by researchers at Stanford, the University of Colorado, Harvard University and Washington University in St. Louis, and recently published in Emergency Medical Journal, is the first randomized, placebo-controlled, double-blind study to examine the use of ibuprofen in ultramarathoners.

The team randomly divided 89 runners competing in 155-mile weeklong races in China, Chile, Ecuador and Sri Lanka into two groups. Runners in one group took 400 milligrams of ibuprofen every four hours while they ran a 50-mile section of their race, and those in the other group received sugar pills. The result: Those who took ibuprofen had an 18 percent higher rate of kidney injury, which can cause symptoms such as fluid retention, difficulty breathing, confusion and nausea.

For every five runners who took ibuprofen, there was roughly one additional case of acute kidney injury, Lipman says. “That’s a pretty high rate. For the first time, there’s strong enough evidence to warn people there could be real side effects.”

If something hurts, ultrarunners might want to consider switching to acetaminophen (Tylenol) and ice baths for pain relief, Lipman suggests. While athletes who suffer acute kidney injuries tend to bounce back quickly, the condition can progress to renal failure. Two years ago, a 40-year-old triathlete died of kidney failure three days after competing in an Ironman race.

So how about the rest of us? Don’t panic just yet. The results of the study are specific to endurance runners and may not apply to people who go on daily jogs or hikes. •