For all the advances in science and technology made in the last century, people often find themselves thwarted by the simplest of problems. There’s still no cure for the common cold, for example. Our conditioner always seems to run out before our shampoo. And we still have no scientifically proven way to avoid blisters. Well, we can cross that last one off the list, at least. A study published today in the Clinical Journal of Sport Medicine reports a simple, cheap method for blister prevention—and it’s available in any drugstore.

Grant Lipman is an emergency medicine doctor working with some of the blister-iest feet in the world: those of runners. "What I kept hearing was, 'Doctor, I'd be doing so well, if only for my feet,'" Lipman said in a press statement. "Their feet were getting decimated."

Military doctors told him that blisters were keeping their patients from completing basic training. The angry sores that form from repeated pressure and friction, and the infections they caused, were hobbling our armed forces.

"People have been doing studies on blister prevention for 30 or 40 years and never found anything easy that works," Lipman said. "I wanted to look at this critically."

So he and a team of his colleagues in emergency and sports medicine put their heads together and decided to test one method that patients had mentioned again and again: paper tape. Paper tape, also known as surgical tape, is a mildly sticky adhesive tape used in hospitals to cover wounds. A roll of paper tape will run you less than a dollar at your local drug store, and anyone can apply it.

Lipman decided to put the tape to the ultimate test: actual ultramarathons. These extreme footraces are legendary for breaking down runners’ bodies and minds. If paper tape could help runners get through an ultramarathon—in this case, the seven-day, 155-mile RacingthePlanet event—that would be pretty good evidence in its favor.

RacingthePlanet runners literally become globetrotters, completing the race's six stages in different parts of the world. Before the event began, researchers recruited 128 runners: 19 participants from the Jordan segment, 35 from the Gobi, 21 from Madagascar, and 53 from the Atacama Desert. Each participant told study staff about their personal blister history.

Medics associated with the study then applied tape to one foot on each runner. If the runner was blister-prone, the medic stuck tape in areas of previous problems. Otherwise, the location of the tape was randomly assigned to one of four blister-likely areas: the toes, instep, outstep, or heel.

Then the race began. By the finish line, 109 participants (that is, 109 feet) remained in the study. On those feet, the researchers found 97 blisters—but only 28 of those were located in taped areas. The cheapo paper tape had blocked blisters in 74 percent of runners.

"It's kind of a ridiculously cheap, easy method of blister prevention," Lipman said. "You can get it anywhere. A little roll costs about 69 cents, and that should last a year or two."