Blisters form when “shearing forces” (also known as friction or rubbing) cause layers of skin to separate. This article will cover a number of techniques for preventing blisters on your feet in the outdoors. For the most authoritative source on the subject refer to the bible of footcare, Fixing Your Feet.
Dry Feet
The first and arguably most important way to reduce friction is to keep your feet dry – think about how difficult it is to put socks on wet versus dry feet. Keeping your feet dry doesn’t just mean not stepping in puddles or staying out of the rain, it means dealing with the quarter liter of sweat that your feet produce every day (more when you’re hiking). If you don’t allow your feet to breathe then this moisture has no way to escape and you’ll end up with wet, blistered feet.
Your choice of footwear greatly affects the ability of your feet to breathe. Sandals are the most breathable followed by shoes with lots of airy mesh such as trail runners. Lightweight hiking shoes which use a combination of mesh and leather-like materials occupy the middle ground while all-leather boots are significantly less breathable.
Bringing up the rear is any footwear with a waterproof-breathable (WPB) membrane such as Gore-Tex or eVent. Although marketed as preventing water from getting onto your feet they unfortunately also prevent water from getting off of your feet to a significant degree. This contributes to sweat build-up and also greatly extends the time needed for your feet to dry out once they do get wet, something which is often unavoidable on longer trips. For these reasons any footwear with these and other similar membranes should be avoided.
To a lesser degree our choice of socks also impacts breathability. Thinner socks are more breathable than thicker socks, and layering socks over one another is less breathable than wearing a single pair. Some socks have extra-thin panels or vents for added breathability, typically on top of the foot.
Wearing socks that are too warm will cause your feet to overheat, increasing the amount of sweat that they produce. Thicker and/or taller socks are typically warmer but you should avoid using socks that are so short that they allow your footwear to rub directly against your ankles or that are so thin that they offer inadequate padding.
Socks primarily contribute to dry feet by wicking moisture away from the skin and into the sock where it can then evaporate. Synthetic socks dry faster and are therefore better at wicking than wool but wet wool feels more comfortable against the skin. The best-wicking socks are manufactured by Drymax whose proprietary technology makes them 25 times drier than any other sock.
Finally, foot powders such as Bromi-Talc can be applied directly to the foot to absorb any moisture present.
Smooth Feet
The ideal texture of the foot is “supple” or soft and smooth. Anything that increases the roughness of the feet also increases the chance of blisters.
The problem of excessively dry and cracked feet can be addressed before a trip by repeated application of moisturizers such as O’Keefe’s Foot Cream. Although severe cases may take up to a week, significant results can be had in just one or two days.
Hardened patches of dead skin such as calluses and corns (formed by rubbing and pressure, respectively) experience much higher friction than regular skin. Blisters which occur beneath a corn or callus are often among the most painful. According to the American Academy of Dermatology these can be removed by soaking your feet in warm water for 10 minutes and then filing them with a pumice stone. A professional pedicure is another option if you don’t feel like doing it yourself.
Long toenails can contribute to the formation of corns on the tops of your toes. Long or rough toenails can also contribute to the formation of blisters under the toenail and black toenails, either by repeated impacts against the front of your footwear or repeatedly catching on socks. Toenails should be trimmed straight across and then filed smooth.
Lubricants such as Foot Glide or Trail Toes can also be applied to the feet during a trip to reduce friction between the foot and the sock.
Reducing and Transferring Friction
Polytetrafluoroethylene or PTFE, more commonly known as Teflon, is one of the slipperiest solids and can be employed as a blister prevention aid. Engo PTFE patches can be applied to the insides of footwear or the tops of insoles to reduce friction. Drymax Blister Protection socks incorporate PTFE fibers (which have one eighth of the friction of wool) to reduce friction between your feet and your socks.
Using a liner sock inside of your regular sock essentially “transfers” a portion of the friction that would normally occur between sock and foot to instead occur between outer sock and liner sock. Double-layer socks such as Wrightsock’s incorporate this concept into a single sock.
Toe socks such as Injinji greatly reduce direct toe-to-toe friction and effectively eliminate between-toe blisters.
Applying tape to your feet, such as paper tape or Leukotape, introduces a barrier which essentially absorbs friction before it reaches your skin. Tape should be applied preemptively to known problem areas and in response to hot spots (areas of discomfort that occur before the formation of a blister), and it should be replaced as it wears down.
In the Field
Even the best-wicking socks may still require significant drying time depending on conditions but changing into a fresh pair of dry socks provides instant relief. You should always have a pair of dry socks to change into.
During short breaks, remove your feet from your shoes to give them an opportunity to breathe and increase the rate of evaporation. You may also try removing any insoles to help them dry as well. During longer breaks, remove your feet from your socks and apply powders or lubricants or replace tape as needed.
If you feel a hotspot forming stop and treat it as soon as possible. Do not attempt to wait it out or ignore it as this will result in blisters, often sooner than you think.
Recommendations
I wear a pair of Oboz Sawtooth Low in the non-waterproof variety. Although less breathable than trail runners I find the mesh side vents and tongue and especially the mesh directly over the toes provide adequate venting. While sandals are the most breathable their openness also allows dust, sand, and grit to easily get onto your feet which can very quickly cause discomfort and blisters.
For socks I use a pair of Drymax trail running socks with PTFE. They feel “different” but not slippery and are unbelievably good at wicking moisture. While expensive they are also very durable, I’ve used my current pair for an entire year including 300km on the Camino de Santiago and they show no signs of wear. Their fit is a bit more on the snug side. They are almost impossible to dry when turned inside out. I have not had a single blister since switching to these socks.
I have never tried Injinji toe socks, and I’ve found double-layered Wrightsocks to be ineffective at preventing blisters.
About three nights before a trip (say, Wednesday for your typical weekend outing) I’ll trim my nails so that any newly-exposed skin has time to toughen up and become less sensitive. I’ll also apply a layer of O’Keefe’s before I go to bed and, if necessary, repeat for the next two nights. I do not bring foot cream with me on hikes.
I do not have any in-the-field experience with foot powders or lubricants (mostly because they are incompatible with my socks) but I’ve tried Bromi-Talc at home and it is the real deal.
I prefer paper tape to Leukotape because it breathes much better. If you soak your feet and wait for the non-taped skin to dry, peeling off paper tape will reveal dry skin whereas the skin under Leukotape will be white and pulpy (“macerated”) – I discovered this after showering with taped feet several times on the Camino. Leukotape is also much more adhesive and will remove hair from your skin and is generally unpleasant to take off. Finally, paper tape tears very easily by hand (although not in clean straight lines) while Leukotape requires scissors or a blade to cut.
I’ve tried silk tape which is more durable than paper tape and gridded so that it tears in straight lines, but it has very poor adhesion to dry skin and I find that the grid pattern is uncomfortable against the skin when walking.
At the beginning of each season I’ll buy new insoles and apply a fresh set of Engo patches to them, usually where the heels and balls of the feet rest.
The End
Thanks for reading! I hope the information in this article helps you stay blister-free in the outdoors.