We’ve all been there: a couple miles into what was supposed to be a long outing on the trail, you feel the hot spot burning inside your shoe. A damn blister. Maybe you’re in ill-fitting new shoes or bunchy socks that caused your feet to sweat. Maybe you just have blister-prone feet. Either way, a skin bubble can put an end to an otherwise great day—or lead to some serious discomfort. Don’t despair: we called up John Vonhof, author of Fixing Your Feet: Injury Prevention and Treatments for Athletes ($20, Wilderness Press), first published in 1997 and now in its sixth edition. Vonhof is a former paramedic and an ultrarunner who now works the medical tents at races like California’s 100-mile Western States Endurance Run and the Badwater 135, as well as Decaman, a series of ten back-to-back Ironmans in New Orleans. He gave us his best advice on blister prevention and treatment.
Take Blisters Seriously
They always seem tiny and innocuous, but they can be day enders. “Even a blister the size of a pea in the wrong spot—at the base of the toe or ball of the foot—can disrupt your gait, meaning pain could go up into your knees or your back,” says Vonhof. “Blisters can seem very minor, but if you don’t take care of them, they can get larger.” He has seen instances where a runner pushed on through a hot spot, not bothering to stop and treat it, and instead of a quarter-inch inflammation, the runner was left with a two-inch bulge covering the whole arch of their foot. Once ripped, a blister leaves a huge patch of raw, exposed skin rubbing the inside of the shoe—not a comfortable situation.
Know the Causes
It’s generally understood that pressure, friction, heat, or moisture can cause blisters to form. When layers of skin and bones move against each other, the inner connections can break down, and a fluid-filled cavity forms. There are a few simple rules to help avoid blister-causing situations. “The most important thing is fit,” Vonhof says. Not enough room in the toe box or too much space in the heel can cause pinching or shifting. Also, Vonhof says, “Skip the cotton socks.” Technical, breathable wicking blends that stay in place are key. We can recommend a few: Balega Blister Resist socks prevent clamminess and eliminate friction, Drymax makes a collection of socks for runners that keep your feet moisture-free, and Injinji’s toe socks keep your digits from rubbing. Mileage matters, too. If you try to run 50 miles off the couch, you’ll probably wind up with blisters. But steadily add distance with a training plan and your feet will thank you.
Prep Your Feet
Proper foot care means good preparation, according to Vonhof. Before a big run or hike, he recommends reducing calluses, trimming and filing toenails, and getting proper insoles for your shoes. If you’re racing long distances, plan to change your socks often, air your feet out at regular rest stations, and carry a foot-care kit (Trail Toes makes a prepackaged blister kit). If you clench your toes, work to relax your feet while running. If you’re prone to blisters or are running ultramarathons, taping problem areas in advance might be a good idea. At Badwater, Vonhof regularly pretapes the entire bottom of a runner’s foot, and he recommends Leukotape K Kinesiology tape since it stays put and molds easily. If you’re running in wet conditions or your dogs tend to sweat, apply a layer of protective, moisture-managing cream, like RunGoo, before putting on your socks. Vonhof likes Squirrel’s Nut Butter Anti-Chafe salve for slathering between toes or on heels to prevent irritation.
Ditch the Moleskin
People used to rub Vaseline on a blister, then cover it with a doughnut-shaped piece of moleskin. These days, Vonhof prescribes lancing. “It’s a debate. Should you lance the blister and get the fluid out or leave it?” Vonhof says. “Sometimes it’ll pop on its own. If it’s in an area where you’re going to continue to put pressure on it while you run or hike, you’re better off lancing it.” To do that, he recommends cleaning the skin first, then piercing it in two places with a sterile pin or needle—a safety pin, tweezers, or pocketknife sterilized with a flame or vodka will work. Gently push the fluid out. (Gravity will also help the blister drain.) Then apply an antibiotic ointment, like Neosporin, and put 2nd Skin or KT tape over the top. Standard Band-Aids don’t stick well and tend to shift.