DOWNHILL SHEAR8,200 FT OF LOSS
Natural Chimneys Park, Virginia · September · 100 km
Foot care for Grindstone 100 km
Grindstone 100 km cooks feet. Heat, sweat, and soft skin.
Threat matrix
What Grindstone 100 km does to feet.
Every line below is computed from published course data or written by PR Run and labeled as such.
- Heat and sweatSeptember highs reach 85 degrees F. Sweat saturates socks, skin softens, friction climbs.Course data
- Hours on feet62.1 miles inside a 18 hour limit. Every hour adds shear, swelling, and sock saturation.Course data
- Downhill shearMile 44.6 to 52.6 drops 2,700 ft at 6.3 percent average grade. Toes hit the front of the shoe, heels lift.Course data
- Technical groundTechnicality 6/10. Rock strikes, side loading, and constant foot correction grind the same spots.Course data
- Long aid gaps12.5 miles between stations at the widest gap. Carry what you need to fix a hot spot alone.Course data
Downhill shear
Where gravity works on your toes.
Sustained descents pulled straight from the elevation profile. Pretape before these, not after.
The schedule
Where you sit down and take the shoes off.
Set your goal time. The clocks, the stop plan, and the kit all move together.
- Natural Chimneys ParkMI 006:00
Eyes only
Named station on course.
- Eyes only. Feel for hot spots through the sock and keep moving.
- Grindstone mile 12MI 1208:54
Eyes only
12.4 mi since the last stop, cutoff 3.6 h.
- Eyes only. Feel for hot spots through the sock and keep moving.
- Grindstone mile 25MI 2511:54
Shoes off
12.5 mi since the last stop, 2,050 ft of descent into it, cutoff 7.2 h.
- Shoes and socks off. Pat completely dry, fresh socks, powder if the last pair was soaked.
- Check toes and nail beds. 2,050 ft of descent came into this stop.
- Pretape hot spots. 1,250 ft down through mile 33 to 42 is next.
- Grindstone mile 37MI 3714:52
Socks and a look
12.4 mi since the last stop, 700 ft of descent into it, cutoff 10.799999999999999 h, late race, feet already soft.
- Socks off. Check the pressure points and swap if the pair is wet.
- Grindstone mile 50MI 5018:08
Shoes off
12.4 mi since the last stop, 2,300 ft of descent into it, cutoff 14.4 h, late race, feet already soft.
- Shoes and socks off. Pat completely dry, fresh socks, powder if the last pair was soaked.
- Check toes and nail beds. 2,300 ft of descent came into this stop.
- Finish VirginiaMI 6221:00
Socks and a look
12.4 mi since the last stop, 1,000 ft of descent into it, cutoff 18 h, late race, feet already soft.
- Socks off. Check the pressure points and swap if the pair is wet.
Checked on top of the essentials for Grindstone 100 km.
Vest / pack
Crew bag
Drop bag
Kit deltas
What Grindstone 100 km adds to the standard kit.
- Powder and a moisture barrierSweat is the friction multiplier on this course.
- Pretape for toes and heelsLong descents load the front of the shoe and lift the heel.
- Vest foot kit you can use aloneThe widest gap is long enough that a hot spot becomes a blister before the next station.
- Moleskin for pressure pointsRock strikes and side loading build hot spots off the usual map.
Shoes
What survives this course.
Matched on terrain, technicality, and distance. Fit still beats every spec, so try them on a long run first.
Crew
What your crew needs on paper.
Two plates. On the left, the race-specific notes that never make it into the standard script. On the right, the printable card your crew reads at two in the morning under a headlamp.
Race day notes
- Crux near Reddish Knob on an eighteen-hour clock near mile 40. Plan foot work before the field splits.
- Surfaces: 85% trail / 10% jeep / 5% paved. Match lugs and tape adhesion to the dominant surface.
- Air band 45°F to 85°F. Crew should carry dry socks and skin lube when heat or rain is in range.
- Cutoff 18 hours. Longer stops only where the schedule has real buffer.
- Educational only. Test every tape, sock, and shoe combination on long runs before race day.
Where you sit down
- Grindstone mile 25MI 25
- Grindstone mile 50MI 50
Print card
A single sheet your crew reads at two in the morning: the stop script, the mandatory kit, and the calls that pull the runner. Print it, laminate it, staple it to the drop bag.
Crew foot care card
Station script. Three to eight minutes if organized.
- Runner sits. Shoes and socks off both feet.
- Inspect: hot spots, maceration, nails, blisters.
- Clean with wipe. Pat completely dry. No tape on damp skin.
- Treat hot spots first. Drain blisters only if necessary with clean technique.
- Fresh socks. Relace shoes. Runner stands and tests before leaving.
Mandatory kit
- Leukotape, kinesiology tape, wipes, blister patches, moleskin
- Scissors, nail clippers, lubricant, powder, spare socks (2+)
- Antibiotic ointment, gloves, cohesive wrap, small towel
When to pull runner: spreading redness, loss of feeling, gait collapse, unmanageable pain.
PR Run · pr.run/foot-care
FAQ
Grindstone 100 km foot questions.
- 01
Where should I stop for foot care at Grindstone 100 km?
Grindstone mile 25 at mile 24.9, Grindstone mile 50 at mile 49.7. Those stops carry the most ground and descent behind them, so a sock change and a tape check pay for the minutes they cost.
- 02
Which section of Grindstone 100 km wrecks feet?
Mile 44.6 to 52.6 drops 2,700 ft at 6.3 percent average grade. That is where toes meet the front of the shoe and heels start to lift. Pretape before it, not after.
- 03
How do I keep my feet dry at Grindstone 100 km?
September highs reach 85 degrees F. Sweat saturates socks, skin softens, friction climbs. Change socks at every stop you can, run powder or a moisture barrier, and lean forward when you dump water on your head so it misses your shoes.
- 04
How many sock changes for Grindstone 100 km?
Plan one at every foot stop you have access to, and carry one spare pair beyond that. 62.1 miles inside 18 hours is long enough that dry socks are faster than the five minutes they cost.
- 05
What goes in my vest for Grindstone 100 km?
12.5 miles between stations at the widest gap. Carry what you need to fix a hot spot alone. Tape, two wipes, a blister patch, and a small tube of lube covers a hot spot without waiting for crew.
- 06
How do I stop blisters at Grindstone 100 km?
Start from the biggest threat on this course. September highs reach 85 degrees F. Sweat saturates socks, skin softens, friction climbs. Fit the shoe with room for swelling, pretape the spots that have blistered on you before, keep grit out, and change socks at every stop you have access to. Blisters come from pressure, friction, and moisture, so remove whichever one this course hands you the most of.
- 07
What foot care kit should I pack for Grindstone 100 km?
Beyond the standard kit, this course calls for powder and a moisture barrier, pretape for toes and heels, vest foot kit you can use alone, moleskin for pressure points. Sweat is the friction multiplier on this course.
- 08
What shoes work for Grindstone 100 km?
85% trail / 10% jeep / 5% paved at technicality 6/10 points toward Norda 055, Hoka Mafate X, Hoka Mafate X. Whatever you pick, race it on a long run first and leave room for feet that swell over the back half.
Educational only. Not medical advice. Persistent pain, infection, or numbness: see a podiatrist or sports medicine clinician.
Train for it
Feet get you to the finish. The plan gets you there on the clock.
Foot care is one system on Grindstone 100 km. Climbs, descents, heat, fueling, and cutoffs are the rest of it.