Painful blisters often plague distance runners. Blisters, as we all know, are caused by friction. Repeated rubbing of damp skin creates more friction than dry skin. Reduce dampness as well as the rubbing, and you'll reduce blistering.

So we all know that to prevent blisters, you need to minimize friction. This begins with shoe selection. Shoes should fit comfortably, with about a thumb's width between your longest toe and the end of the shoe. Remember that this is often your second toe, not your great toe! Narrow shoes can cause blisters on the great toe and little toe. A shallow toe box can lead to blisters on the tops of the toes, while loose shoes can create blisters on the tips of the toes. Shoes that are too big can cause sliding of your foot which can blister the soles as well as the tips of your toes.

Always try on shoes in the afternoon or evening, because feet tend to swell during the day. Walk or run around the store before buying them and then wear the shoes around the house for 1 to 2 hours to identify any areas of discomfort. It often helps to break in shoes by wearing them for 1 to 2 hours on the first day and gradually increasing use each day.

Socks can decrease friction between the feet and shoes. Coolmaxx or synthetic moisture wicking socks or even special double-layered socks can minimize shearing forces. These can wick moisture away from the skin more effectively than wool or cotton can, further decreasing the likelihood of blisters. You can also carry extra pairs of socks to change into if your socks become too damp on a long run.

Another preventive measure is to use padded insoles or moleskin to decrease friction in a specific area. Drying agents can also help. Foot powders and spray antiperspirants are inexpensive ways to decrease moisture. For severe sweating, there are prescription antiperspirants you can get from your physician that provide even more effective drying.

A study of West Point cadets revealed a more than 50% decrease in blisters in those cadets that used spray antiperspirant before running, but many experienced some skin irritation; so test the antiperspirant on a patch of your foot before trying this on the run.

A thin layer of petroleum jelly or Body-Glide can also be applied to the feet to decrease friction. Conditioning the skin by gradually increasing activity tends to lead to formation of protective calluses rather than blisters.

Blisters are a fact of life in distance runners. Almost one in three marathon runners experience blisters at some point in their training.

So how should a blister be treated?


  • If the blister is small and not painful, leave it alone! Place a small band-aid or piece of moleskin over it to protect it and treat the cause so it will not become bigger.
  • Large or painful blisters that are intact should be drained without removing the roof. This is a biological barrier and helps with healing. First clean the blister with alcohol or antibiotic soap and water. Then heat a pin over a flame until the pin glows red, and allow it to cool before puncturing a small hole at the edge of the blister. Drain the fluid with gentle pressure, then apply an antibiotic ointment and cover the blister with a bandage. Change the dressing daily—more frequently if it becomes wet, dirty or loose.
  • Once your blister has been drained, you should treat it as an open wound. Dress it daily with a bandage. Keep it dry and clean for a couple days and if you engage in the activity that caused it in the first place before it heals, take care to provide extra padding and secure the area to prevent any rubbing that may irritate the wound. Change the dressing anytime it becomes moist or soiled and keep an eye out for infection.

When should I see a doctor for a blister?

If you experience increased redness, swelling, pain, or green or yellow discharge you should take it to your physician immediately to make sure it's not becoming infected.

Bottom line: blisters are a common annoyance for many runners. These tips should help you conquer this pesky problem before it slows down your run.