What the Trial Found
In a randomized trial at four 250 km six-stage desert races, 83% of 128 runners blistered, and 3M Micropore paper tape on their blister-prone spots cut blister incidence by 40 percentage points. Lifted tape was the most common reason the method failed, which is why spare rolls and early access drive the quantities below. The trial details, the taping method, and an earlier trial that found no effect are in Blister Prevention for Ultramarathons.
The Kit List
| Item | Potential Use | Safety Note |
|---|---|---|
| Paper tape | Cover a known hot spot on intact skin. The trial used 3M Micropore, 1 inch on toes and 2 inch on the heel. | Test adhesion in training. Stop if it wrinkles, constricts, or irritates. Do not tape broken skin. |
| Lube or balm (optional) | Reduce friction at a familiar rub point, if it worked in training | Keep it off skin you tape, because it stops tape sticking. Stop if irritation or grit makes rubbing worse. |
| Scissors | Cut tape cleanly | Use only in a safe, well-lit place and keep them away from skin |
| Dry socks | Replace a wet, gritty, wrinkled, or rubbing pair | Test each sock-and-shoe combination before race day |
| Towel | Dry feet before tape or socks | Keep it clean and separate from used dressings |
| Hydrocolloid and non-stick dressings | Cover a drained or torn blister | Smooth every edge so it cannot roll inside the sock |
| Alcohol wipes, sterile needles or lancets, gloves | Clean and drain a large blister | Individually wrapped. Follow the drainage steps in the blister guide. |
| Alternate footwear (optional) | Address a specific fit, traction, or weather issue | No default size increase; test for both pressure and slipping |
Illustrative Quantities
The counts below are a packing example, not a dose from the trial. They use the same crewed 1-mile loop as the 24-hour gear checklist: 8–18 °C, no rain, a table every lap. A self-supported stage race has to carry the resupply that the table would have held.
| Item | Crewed 24-hour loop | Six-stage self-supported week |
|---|---|---|
| 1-inch paper tape | 1 roll at the table | 2 rolls in the pack, because adhesion failed for some trial runners and a lifted strip has to be replaced |
| 2-inch paper tape | 1 roll at the table | 1 roll in the pack, for heel and metatarsal-head strips |
| Dry socks | 6 pairs: one change every 4 hours with no rain | 1 pair per stage, plus 1 spare. Sand and river crossings use the spare early. |
| Small scissors | 1 pair, in the feet box | 1 pair, if the rules allow a blade. Some mandatory lists already require a knife. |
| Small towel or gauze | 2, so one can be wet while the other is dry | 1, kept in a zip bag away from used dressings |
Eighty percent of the trial's blisters had appeared by the end of stage 2. Pack the tape where you can use it on the first afternoon, not at the bottom of a bag you open on day four. If the event bans scissors or requires a different kit, the rulebook wins.
The Hot-Spot Rule
A hot spot means stopping at the next crew point or aid station, not the one after. The kit exists to make that stop take minutes: the towel, tape, scissors, and a dry pair should come out of one bag together. What to do with the foot itself, from a hot spot to a blood blister, is in the mid-race blister management steps.
Packing System
Keep the foot kit in one obvious bag. Do not scatter tape in one box, socks in another, and scissors somewhere mysterious. Label it "FEET" in large letters and tell crew to bring the whole bag when you mention rubbing.
Pair the kit with a tested shoe rotation strategy.
After the Race
Wash and dry feet gently, then restock the kit before the next stage or race: refill tape and dressings, and wash the towel. Blister care and the signs of infection are in the blister guide, and the day-by-day recovery timeline covers the weeks after the finish.
Sources
- Lipman, G.S. et al. (2016) — Paper Tape Prevents Foot Blisters: A Randomized Prevention Trial Assessing Paper Tape in Endurance Distances II (Pre-TAPED II). Clinical Journal of Sport Medicine, 26(5), 362–368. Source of the 128-runner sample, the 83% blister rate, the 40 percentage-point reduction, the 80% of blisters by stage 2, the adhesion failures, and the 1-inch and 2-inch 3M Micropore method.
Frequently Asked Questions
What tape should you use for ultra blisters?
The strongest ultramarathon trial used 3M Micropore paper tape on blister-prone areas and compared it with untaped skin on the same foot. The authors report an absolute reduction in blister incidence of 40%. Lack of adhesion was the most common reason the tape failed. Test the exact tape on your skin before race day, and stop if it irritates, wrinkles, or constricts.
What goes in a blister kit for an ultra?
Paper tape in 1-inch and 2-inch widths, small scissors, a towel, dry socks, hydrocolloid dressings, and alcohol wipes with individually wrapped sterile needles. For a crewed 24-hour loop without rain, the illustrative counts are one roll of each tape, six dry sock pairs, and two towels. A six-stage self-supported race needs two rolls of 1-inch tape and one of 2-inch tape in the pack.
How often should you change socks?
There is no fixed interval for every race. On the illustrative crewed 1-mile loop in the 24-hour gear checklist — 8–18 °C and no rain — the packing assumption is one dry pair every 4 hours, six pairs in the day. Rain, a longer loop, or a self-supported stage means you change when the pair is wet, gritty, or wrinkled, and you pack for that access.