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An Ounce of Prevention: Stopping Blisters


By Tom Demerly

You have a $5000 bike, $3000 wheels, $1500 power meter, $250 cycling shoes, $150 running shoes and a $600 wetsuit. Another $2000 on coaching and $550 on an entry fee after $3500 in travel, hotels and rental cars. More importantly, you’ve done the training, put in the time.

For a want of a $1.49 packet of BlisterSheild you could lose minutes- our hours in a race. Or not finish at all. Blisters can be a race killer. Once they form they prevent you from concentrating on your race. They are painful to the point of hobbling you on the run. Once you have blisters your training schedule is dictated by your feet, not your coach.

I didn’t aspire to it, but I’ve become an expert on blisters and foot care in endurance races. I’ve raced on all seven continents, from Antarctica to the Sahara Desert to the Jungles of Vietnam and climbed the highest mountains on three continents. Wet conditions, dry conditions, arctic conditions and tropical conditions, deserts and mountains. The first thing I learned about blisters is simple: Prevent them.

“The first thing I learned about blisters is simple: Prevent them.”

Blister prevention requires proactive effort and planning. While most athletes put in the training on every other aspect of performance, blister prevention usually gets ignored until it is too late. Once it is too late and blisters have formed, you will slow down. It will cost you time. You will suffer.

Blisters on your feet are caused by friction, friction is caused by movement. Your first line of defense against blisters is footwear selection that reduces or removes movement. A good running shoe fitter will not only evaluate your gait but use a Brannock device or other measuring tool to verify your size. Even if you know your shoe size you should be measured for active footwear like running shoes for use in an environment where blisters can be a deal killer. Your fitter will also evaluate your foot volume and shape, critical aspects of selecting the right size, brand and model.

Not all shoes are created with blister prevention in mind. As more athletes have chosen to go sock-less for faster transitions in triathlons a new culture of footwear has emerged designed specifically for use without socks.

The decision to go sockless is an easy one. For most events including a half Ironman sockless is the way to go- provided you are using the correct shoes and blister prevention strategies. First, experiment with sockless running using your chosen blister prevention during training. The reasons to go sockless include faster transitions and, when done correctly, actually reduce the chances of blisters on the run. Socks can absorb water from aid stations and other fluids during the run. Once wet they are more likely to create friction- and friction creates blisters.

Zoot Sports has designed most of their line to be bare foot friendly even in the most demanding race environment. A bare-foot specific run shoe has a long list of conflicting requirements: It must provide a friction free layer next to bare skin. It must fit consistently when wet and dry. It must not trap or pool water, perspiration and urine (you think a sub 10 hour Ironman competitor stops to pee?) and it must manage moisture over hours of exertion in wide temperature ranges.

Zoot uses three technologies to prevent blisters for sockless runners: BareFit, Tri-Dry and Dri-Lex Fabric. Basically the internal of the shoes are free of abrasive seams and stitching and use a moisture management fabric that does not swell or expand when wet, changing shoe fit. Additionally, the sole of the shoe and the midsoles have drain holes so an aid station cup dumped over your head drains effectively keeping the shoes light and avoiding pooling inside the shoe which changes shoe fit and begins the blister cycle.

Even with good shoe design blisters can still form. The ultimate blister birthplace may be the sand beach run at the annual U.S. Navy SuperSEAL and SuperFrog triathlons. These are salt water swims, setting up the blister cycle since salt water is more abrasive. The event incorporates a beach run in loose sand, the same sand used by Navy SEAL candidates in their training.

At SuperSEAL and SuperFrog I’ve used Zoot shoes with Brave Soldier Friction Zone. Friction Zone is a “wet” blister shield, like the consistency of caulking or non-abrasive toothpaste. It uses primarily natural ingredients like soybean oil, beeswax with silicone, shea butter, macadamia nut butter and hemp seed oil along with a wax-based paraben (propylparaben). You squeeze it into your shoes around the entry and, as your foot slides into the shoe in T2 it spreads where it needs to and facilitates lightening fast shoe entry. The outer fabric of most Zoot shoe models resists sand intrusion so your anti-friction goo inside your shoe remains relatively clean and free of grit.

The first decision you make about blister prevention is whether you are going to rely on a “wet solution” such as Friction Zone, BodyGlide or SportSheild roll-on or a dry blister prevention such as BlisterSheild foot powder or Dr. Scholl’s MoleSkin’s. This decision is made mainly by event. If you are swimming first and your feet are going to be wet going into your shoes, either from the swim, from rain or from aid station cups dumped over your head on a hot day then using a wet lube and seamless inner running shoe is a viable strategy with no socks.

If you are doing a stand-alone running race in dry conditions such as a trail run or marathon where you may be using a CamelBak (as opposed to aid station cups which allow fluid to splash down into your shoes) then a dry solution such as BlisterShield and Dr. Scholl’s MoleSkin combined with blister management socks like double layer WrightSocks is an effective blister prevention strategy. BlisterSheild is a powder with a talcum-like consistency that has an uncanny ability to eliminate friction. Even on extremely hot days when feet perspire heavily BlisterSheild powder remains dry and effective at eliminating friction. You apply blister shield by spooning it into your shoe and sock- a little goes a long way. If you shake your sock with the top held shut it will distribute the powder evenly. Used in your shoes without socks BlisterSheild is effective until it gets really soaked.

Another viable blister prevention especially suited for daily training when you don’t want to use some type of topical application on your feet are WrightSocks double layer, anti-friction socks. WrightSocks uses an amalgam of elegant technologies to resist blister formation and reduce friction. Firstly, the sock is actually two completely seamless layers. The interaction between the layers reduces friction between the sock inner layer and the skin by transferring it to the two layers in the sock. WrightSocks Dri-WRIGHT II fabric helps manage moisture and is non-absorbent, meaning it does not swell or become baggy when soaking wet. Fit is another innovation with WrightSocks with their Y-Heel and Stabilizer Zone fit sold in color coded sizes so you can match up the same size socks out of the laundry.

2Toms, the makers of BlisterSheild also distribute a wet solution called SportSheild. SportSheild is available in a roll on or inn towelettes. It is convenient to apply and perfect for triathlons where you feet will be wet coming off the bike and will stay wet when you keep dumping water over yourself in aid stations.

If you only use one friction reduction product BodyGlide may be the answer. It is not as tenacious as BlisterSheild but works well for most of the run even when wet. BodyGlide rolls on like underarm deodorant and is available in different formulas that include sunscreen. Simply apply generous amounts of BodyGlide to the insides of your shoes where friction could accumulate prior to the race.

BodyGlide also has a new “Liquefied Powder” skin lubricant that goes on as a paste and dries quickly to form an incredibly slippery surface. This “dry shield” is convenient to apply inside shoes for a triathlon or directly to feet for a long run.

The key to using blister prevention products is trying them before race day. Practicing with shoe fit and selection and using different wet and dry friction reduction strategies will teach you which one works best before blisters have a chance to ruin your “A” race.