If you’re a runner, there’s no doubt you’ve experienced blisters before.
They are an incredibly common running injury, and while some of us are more susceptible than others, whether you are running a 5K or an ultra, they can strike any runner’s feet. 1Brennan, F. H. (2002). Managing Blisters in Competitive Athletes. Current Sports Medicine Reports, 1(6), 319–322. https://doi.org/10.1249/00149619-200212000-00003
Sometimes you are expecting them and other times they come as a surprise, leaving many runners limping to the finish line.
However, blisters don’t have to occur.
Blisters require three things to propagate: heat, friction, and moisture.
By minimizing these three elements, you can drastically reduce the risk of developing blisters while running.2Blisters on Feet: Causes and Treatments. (2017, May 18). Healthline. https://www.healthline.com/health/blisters-on-feet#diagnosis
A nice and blister-free foot (we didn’t have the heart to show you full-blown blisters)
What Are Blisters?
Blisters are pockets of fluid that form on the outside of your skin.
They often look like bubbles or bumps, and most are filled with a clear liquid. Occasionally, they can be filled with blood, which are known as blood blisters.
What Causes Blisters For Runners?
The primary cause of blisters is friction between your skin and socks. Your body reacts to the friction by gathering fluid. This fluid continues to build up until it collects under the outermost layer of your skin and forms a bubble.
Heat and moisture can cause more friction, which, unfortunately for most runners, is very common.
So, if you get really sweaty or run in the rain, you are much more likely to get running blisters.
You may also get blisters if your shoes don’t fit properly. If you have ill-fitting shoes that are too small or tied too tightly, then your feet might rub against the shoes and cause blister formation.
Conversely, if you wear poor-fitting shoes that are too big, then your feet will slip around too much in your shoes. This poor shoe fit can cause friction, leading to (you guessed it!) more blisters.
Blisters are more common if you are wearing new running shoes, as it can take time for your feet to adjust and for the shoes to be worn in.3Knapik, J. J., Reynolds, K. L., Duplantis, K. L., & Jones, B. H. (1995). Friction blisters. Pathophysiology, prevention and treatment. Sports Medicine (Auckland, N.Z.), 20(3), 136–147. https://doi.org/10.2165/00007256-199520030-00002
How Should Runners Treat Blisters?
Most medical professionals recommend leaving a blister alone.
Small blisters usually go away within a day, and even bigger blisters will become smaller after a day or two.
It’s best to let the blister stay because the fluid and bubbled-up skin are protecting the layers of skin underneath!
When you pop a blister, the bacteria that live on the outside of the skin can get into the raw area underneath and become infected.
However, sometimes blisters pop on their own, or you may be in too much pain to walk or run. If so, you can pop the blister. It’s imperative to use a sterilized needle when popping a painful blister. This means you should hold it against a flame, rub it with rubbing alcohol, or boil it. And then, make only small holes so the fluid will drain.
Whether you pop the blister yourself or it pops on its own, make sure you cover it with a bandage to keep it clean and prevent infection. This will also keep a new blister from forming on the raw skin.
You may also want to apply antibacterial medicine, like Neosporin, or antibiotic ointment.
Just be sure to change the bandage out regularly and keep the area clean until the skin has time to heal fully!
If you’re struggling with a blister under your toenail, then check out our specific guide on how to treat it.
How Can Runners Deal With Blisters While Running?
If you need to run and still have a blister, you can take steps to prevent it from popping while you run.
The first is to invest in moleskin.
Cut a hole in the moleskin that is the size of the blister and then place it around the blister. You can then cover the entire area with a bandage. You can use band-aids or KT tape that is designed for blisters. In a pinch, some runners like using duct tape! This should cushion the area enough that it won’t become infected.4Lipman, G. S., Sharp, L. J., Christensen, M., Phillips, C., DiTullio, A., Dalton, A., Ng, P., Shangkuan, J., Shea, K., & Krabak, B. J. (2016). Paper Tape Prevents Foot Blisters. Clinical Journal of Sport Medicine, 26(5), 362–368. https://doi.org/10.1097/jsm.0000000000000319
If you develop a blister while running, you can continue running unless it becomes too painful.
If you keep moleskin or tape with you, you can stop and treat the affected area right away. Otherwise, don’t push it.5Scheer, B. V., Reljic, D., Murray, A., & Costa, R. J. S. (2014). The enemy of the feet: blisters in ultraendurance runners. Journal of the American Podiatric Medical Association, 104(5), 473–478. https://doi.org/10.7547/0003-0538-104.5.473
If you feel a lot of pain, stop running! Go home, rest, and treat the blister in the way described above.
If you are running a big race, stop by a medical tent if your blister is bothering you. They should have the supplies on hand to tape you up quickly and get you back on track.
How Can Runners Prevent Blisters?
There are a few ways to prevent blisters when you go for a run.
The first is to invest in the right gear.
Investing in quality running socks can go a long way in preventing blisters.6Worthing, R. M., Percy, R. L., & Joslin, J. D. (2017). Prevention of Friction Blisters in Outdoor Pursuits: A Systematic Review. Wilderness & Environmental Medicine, 28(2), 139–149. https://doi.org/10.1016/j.wem.2017.03.007
Look for moisture-wicking socks, especially if you sweat a lot. These will help your feet stay dryer when you run.
Running socks also usually don’t have seams, which means there is one less surface to cause friction while you run. To further help with blister prevention, some runners prefer wearing double-layered socks so that the only friction they experience is between their socks and the shoe.
Invest In Toe Socks
Getting blisters between your toes?
Eliminate any toe rubbing altogether with a pair of toe socks. Their glove-like design isolates each and every toe, meaning blisters won’t form.
We recommend Injinji toe socks – check them out.
After you invest in the right socks, it’s time to get fitted for your shoes.
If you haven’t visited a running store to get fitted, we highly recommend it. The employees at running stores are often runners themselves and can help you understand how your new shoe should fit and feel.
When you run, your feet swell, and you need shoes that will accommodate this swelling.
The general rule is to size up a half size in running shoes, but you may need a full size larger than your normal shoe.
Now that you have your basic gear, you can take even more steps to prevent blisters if you are especially prone to them. You can apply kinseo tape, moleskin, and yes, duct tape to the areas where you usually blister. This will reduce the friction in that area, protecting your skin.
You can also use lubrication in the form of Vaseline, Aquaphor, or products like Body Glide. Having your feet well lubed actually reduces friction and should prevent blisters.
However, be sure not to apply too much, otherwise, you’ll be slippery in your socks. If you don’t like using lubricant, you can use powders or sprays designed to keep your feet very dry. We recommend experimenting with both options to find the one that works best for you.
Finally, if you enjoy getting pedicures or do them at home, avoid removing the calluses on your toes and feet. Though not pretty, they serve as protection and will keep those parts of your feet from blistering.
Beating Blisters
Blisters happen to everyone.
Sometimes, you get stuck in the rain or pour too much water on yourself on a hot day.
The best protection is to wear moisture-wicking toe socks such as Injinjis and properly fitted shoes.
However, some runners are more prone to blisters than others, so you may need to rely on anti-chafing lubricants or powders to get you through your long runs.
If you follow the preventative steps outlined above and are still struggling at a lot with blisters, consider seeing a podiatrist.
How Long Does A Friction Blister Last?
The good news is that even though blisters can be painful, they usually go away on their own after a day or two.
So, don’t worry if you need to take a rest day after a painful, blister-filled run.
You’ll be back up and running again in no time!
If you’re still struggling with more than blisters, take a look at our in-depth guide to running injury prevention.
running in Texas my shoes are squishy from sweat by the end of a long run, and no wicking sock will prevent this. my feet are often macerated from the moisture. aside from trail toes or vaseline everywhere I guess there arent other options. I have thought about running loops and changing into dry shoes and socks each loop but that takes time!