Fix your feet
before they fix your race.

The friction stack

A blister is not rub. It is shear between skin layers, driven by bone moving inside a foot that is being pressed, rubbed, wetted, and heated at the same time.

That is useful because it gives you five levers instead of one product. You do not need to solve all five. You need to find which one this course hands you the most of and take that one away.

• Bone movement: fit and lacing control how much the foot travels inside the shoe.
• Pressure: toe box width, seam placement, insole shape, lace tension.
• Friction: lubricant when dry, tape where you have history.
• Moisture: sock fiber, sock changes, powder, barrier cream.
• Heat: ground temperature, sock thickness, airflow, ice.

Fit is the whole game

Loose lets the foot slide, which is shear. Tight cuts circulation and presses, which is pressure. Both end in the same place.

A thumb width from the longest toe to the end. Heel locked with no lift. Toe box wide enough that toes spread when you land, because they do land spread.

1. Measure both feet sitting and standing. Feet lengthen under load.
2. Fit the larger foot. They are not the same size and you only get to pick one.
3. Try them in race socks. A sock is a whole half size of volume.
4. Jog. Find a slope. Heel lift shows up going downhill and nowhere else.
5. Pull the insole out and stand on it. If your foot spills over the edge, the shoe is too narrow no matter what the length says.

Socks are equipment

No cotton, ever. Cotton holds water and welds itself to soft skin.

Double layer socks move shear into the sock instead of into your skin. Toe socks solve inter toe blisters and cause problems for people who have never worn them, which is why you test them in training.

• Wool or synthetic. Thickness is a fit variable, so pick it before you pick the shoe size.
• Retire socks when the fabric pills or the cuff stops gripping. Flat fabric has stopped wicking.
• Turn a new pair inside out and find the seams before a race finds them for you.
• Carry one spare pair beyond your plan. Plans get wet.

Lacing is free and nobody practices it

Two lacing patterns solve most fit problems that shoe shopping cannot. Learn them with cold hands.

• Heel lock through the top two eyelets stops heel lift on descents.
• Skipping an eyelet over a pressure point takes tension off a hot spot without loosening the whole shoe.
• Retie at the top of a long climb. Feet have swollen and the tension you set at the start is now wrong.
• Gaiters over the collar for dust, decomposed granite, volcanic ash, and sand. Fine grit still gets through a mesh toe box, so plan to shake shoes out too.

Lube, powder, and barrier cream do different jobs

Lubricant lowers friction while skin is dry enough to stay lubricated. Powder absorbs moisture and buys time in heat. Zinc oxide and barrier creams keep water out of skin on courses where your feet are simply going to be wet.

Petroleum jelly is the wrong tool. It traps heat, it does not absorb, and over enough hours it helps skin macerate.

• Dry and hot: powder, and lubricant only on the spots with history.
• Wet or humid: barrier cream, and accept that you are managing water rather than avoiding it.
• Reapply when you change socks, not on a separate schedule you will forget.
• Skin tougheners and tape adherent help tape hold. They also sting on broken skin.

Pretape history, not everything

If you have blistered the same spot three times, tape it before the start. If you have never blistered somewhere, tape is just another edge that can wrinkle.

Tape goes on clean dry skin. Tape on damp skin peels, rolls into a ridge, and creates the blister it was meant to prevent.

1. Wipe with alcohol. Let it flash off completely.
2. No lotion, no lube, no powder under the tape.
3. Lay the strip down without stretching it. Stretch is tension and tension is a new pressure point.
4. Smooth every edge. Run a thumb around the whole perimeter.
5. Stand up, put the race sock and shoe on, and walk. Wrinkles announce themselves immediately.

Insoles and nails

• Stock insoles are thin and generic. An aftermarket insole matched to your arch can fix a hot spot the shoe cannot.
• Custom orthotics get broken in over long runs, never introduced on race morning.
• Trim nails straight across, then file the corners smooth. A sharp corner cuts the toe next to it.
• Trim four or five days out, not the night before. Fresh short nails are tender.

Heat: the problem is sweat, then it is the ground

In heat your socks saturate from the inside. Skin softens, friction climbs, and the shoe that fit this morning is now full of a swollen foot.

On pavement in real heat there is a second problem. The road conducts heat up through the sole and cooks the bottom of the foot. That blister is a burn, and taping it does nothing.

• Change socks at every stop you can reach. Dry socks are the highest value five minutes in ultrarunning.
• Powder in the toe box on desert courses. Reapply with each sock change.
• Lean forward when you pour water over your head so it runs off your chest and not into your shoes.
• Ice in the sock cuff, not against bare skin for long stretches.
• On hot pavement, a thicker sole and a lighter colored upper both buy real time.

Wet: stop trying to stay dry

On a wet course your feet are going to be wet. The plan is not avoidance, it is limiting how long skin stays waterlogged and keeping grit out of the sock while it is.

Macerated skin is pale, wrinkled, and soft. It tears instead of blistering, which is worse, because a tear has no roof over it.

1. Change socks after the crossing, not before it.
2. Pat feet dry. Do not rub. Rubbing takes the top layer off soft skin.
3. Barrier cream on the areas that macerate first, usually between and under the toes.
4. Shake the shoe out. Water carries grit in and leaves it behind.
5. Give feet ten minutes of air at a crew stop if the clock allows it.

Grit: sand, granite, and volcanic ash

Grit is friction in granular form, and it does not stop when you stop. It sits in the sock and sands the same spot for as long as you leave it there.

Decomposed granite, desert sand, and volcanic pumice all behave differently. Ash is the worst of them because it is sharp and fine enough to pass straight through a mesh upper.

• Gaiters over the sock and shoe collar. This is the single highest return piece of foot gear on a gritty course.
• Empty shoes and turn socks inside out at stops. Do it on schedule, not when it hurts.
• Rinse feet if there is water to spare. Grit plus sweat becomes a paste that tape will not stick over.
• Gaiters do not solve mesh. Expect some to get in and plan the shake out.

Cold: wet plus cold is the dangerous one

Cold on its own makes feet numb, which mostly means you stop noticing damage. Cold plus wet over hours is trench foot, and that is a tissue injury rather than a skin injury.

Cold also breaks your foot care. Tape will not stick to cold damp skin, and your hands will not work well enough to apply it.

• Dry socks in every bag you will reach after dark. Not one spare, one per bag.
• Warm the foot before you tape it. Hands on the foot for a minute is enough.
• Numb toes get checked visually, because you cannot feel what is happening.
• Waterproof socks help until water goes over the cuff, then they hold it in.

Multiday: day three is the whole event

Anything past two hundred miles is a skin durability problem. Damage from day one never heals, and by day three you are working on feet that are soft, swollen, and thin.

Sleep debt is a foot care problem too. Tired runners skip the stop, and tired crew tape over wrinkles.

• Two or three pairs of shoes, with the later pairs a half size up.
• Rotate pairs so a wet pair gets to dry instead of staying wet for a hundred miles.
• Foot stops go on the schedule with the sleep stops. Feet up whenever you are horizontal.
• Assume you will be draining and patching, and stage the supplies for it rather than hoping.

Hot spot: stop at the top of the climb

A hot spot is a warm, tender patch. There is no roof yet, which means you can still fix it with tape and lose almost nothing.

Runners talk themselves into the next aid station. The next aid station is nine miles away and the hot spot becomes a blister in two.

1. Sit down. Shoe and sock off. Look at it.
2. Wipe, dry completely, tape flat over the spot with the edges smoothed.
3. Find the cause while you are in there: grit, a seam, a lace, a wet sock.
4. Stand, walk five steps, then go.

Blister: the roof is the bandage

An intact blister roof is sterile cover over raw skin. Keep it if you possibly can. Drain the fluid when pressure is changing your gait, and leave the roof in place.

Once the roof is gone you have an open wound on a foot that is going into a shoe for another several hours. Cover it properly and watch it.

1. Decide whether you can offload it instead. A donut pad and a lace change beat a needle.
2. If draining: wipe the skin, sterilize the needle, puncture at the edge and low, press the fluid out.
3. Leave the roof. Ointment, then a pad or a moleskin donut around it.
4. Tape over the top with anchor strips that reach onto normal skin.
5. Sock, shoe, stand, walk. If it still hurts the same way, the pad is in the wrong place.

Torn skin and maceration tears

Torn blisters and macerated tears are the hardest thing to fix mid race, because there is no dry intact skin to build on and no roof to protect the wound.

The goal changes from prevention to containment. You want the wound covered, the pressure moved somewhere else, and no more grit getting in.

• Clean gently, dry the surrounding skin thoroughly, then work outward from the wound.
• Hydrocolloid over the wound if you have it, then a moleskin donut so the pressure sits on the ring.
• Anchor tape onto healthy skin well beyond the pad. Nothing sticks to a wound.
• Fresh socks are not optional here. A dirty sock over an open wound is how the race ends in a clinic.

Nails and black toes

• A black toenail is a bruise under the nail from repeated contact with the front of the shoe. Descent and toe box room, in that order.
• If it is painful and pressurized, that needs a clinician, not a needle at an aid station.
• A lifting nail gets taped flat so it cannot catch. Leave it attached.
• After the race, protect it, keep it clean, and let it grow out. Watch for infection for two full days.

Brief them before race week

Your crew needs to know your foot history, which spots you always blister, which products you have tested, and what you want done at each stop. Written down, on one page, in the bag.

Pick one person as foot lead. Foot care by committee at mile 70 is how wrinkled tape happens.

• Your history: which spots, which races, what worked last time.
• Your products, by name. Not a category, the actual tube and the actual tape.
• Which stops are full foot stops and which are pass throughs.
• Permission in advance: tell them to look even if you say the feet are fine.

The stop, in order

Same sequence every time so nothing gets skipped when everyone is tired. Chair, light, gloves, then feet.

1. Runner sits with the foot up where you can see it. Get real light on it.
2. Both shoes and socks off. Both. The problem is usually on the foot they did not mention.
3. Look and say out loud what you see: hot spots, tears, maceration, nails, grit.
4. Wipe, then pat completely dry. Dry is the step people rush and it is the step that decides whether tape holds.
5. Treat, tape, fresh socks, relace with the foot flat on the ground.
6. Runner stands and walks five steps before they leave. Fix it now if something feels wrong, because in two minutes they are gone.

Clean, dry skin before tape. Tape on damp skin peels into a ridge and makes the blister it was meant to stop.

What lives in the crew bag

• Strong rigid tape and kinesiology tape. Both, they do different jobs.
• Alcohol wipes, and more than you think. Every stop uses two.
• Hydrocolloid patches, moleskin, gel pads.
• Scissors, nail clippers, nail file.
• The runner's tested lubricant and powder. Their brand, not yours.
• Multiple pairs of socks. Multiple.
• Antibiotic ointment, nitrile gloves, a sterile needle used with judgement.
• A small towel that stays dry, and a headlamp that is not the runner's.

The calls your crew has to make

Some of this is not taping, it is judgement. Agree on it before the race so nobody is deciding it while a runner begs to leave.

• How long a foot stop is allowed to take before it costs a cutoff.
• What you do if the runner refuses to take their shoes off.
• What signs mean the runner sees medical instead of the crew chair.
• Who says the word if the day is over.