Ask the Experts: Blisters

I’m training for a fall marathon and I’ve been ramping up my mileage on the weekends. On my last two long runs, I’ve developed blisters on the side of my heel. Do I need new shoes?

-Vida B. Washington, D.C.

Chances are, you probably don’t need new shoes. The blame for your blisters probably lies more with your socks than your shoes. While you’ve been increasing your mileage, mother nature has been increasing the temperature. Long, hot runs make for sweaty feet and they’re made even wetter by sweat that drips down your legs and into your shoes. If you’re wearing cotton socks, all that wetness is just absorbed. Wet socks expand, slip and slide all around your feet and the friction of that motion causes the development of blisters.

Look for socks that wick moisture away from your feet. In general, wicking socks are a cotton/polyester blend or a cotton/nylon blend. Different brands use different names. Nike has Dryfit. Adidas has ClimaCool. Saucony uses CoolMax fabric. Generally, a thinner sock is desirable in the summer. Make sure your shoes are tight enough to prevent your foot from slipping around, but not so tight that you restrict circulation.

If you’ve already got a blister, you can still go for a run. You’ll want to cover it with something. Bandages and moleskin don’t hold up very well once your feet get sweaty. I recommend using Duct tape. Apply the duct tape while your foot is dry. Make sure to cover the blister and plenty of skin around it. The duct tape is sticky enough to stay in place and the outside is slick enough to reduce friction. Cover the duct tape with your sock and go for your run.

If you use duct tape, make sure to remove it immediately after you run. It’s a temporary tool to get you through your run, not a long term solution. You may find that the blister will break while you remove the duct tape (don’t worry, it doesn’t hurt). If that happens, clean it and apply antibiotic ointment and a bandage. You can protect the tender area with duct tape again the next time you run.