Races
Fun Trails Chichibu & Okumusashi
Japan, November. 105 km on 75% trail. +25,259 ft of climbing. 30 hours cutoff.
- Start968 ft
- High3,043 ft
- Low418 ft
- Finish968 ft
- Japan at mile 0.0
- Fun Trails Chichibu & Okumusashi mile 13 at mile 13, cutoff 6 hours
- Fun Trails Chichibu & Okumusashi mile 26 at mile 26, cutoff 12 hours
- Fun Trails Chichibu & Okumusashi mile 39 at mile 39, cutoff 18 hours
- Fun Trails Chichibu & Okumusashi mile 52 at mile 52, cutoff 24 hours
- Finish Japan at mile 65, cutoff 30 hours
Geometrycourse math
Weather at the cruxcourse math
At hour 8 of race, feels like 20 C (66 F).Sample of 7 race days, medium confidence.At hour 8 of race, apparent temperature P90 is 20 C / 68 F.
The cruxHumid climbs, ridge exposure, and aid gaps in remote terrain (near mile 42)
Course DNA
The Course
Fun Trails Chichibu & Okumusashi runs 105 km through Japan. +25,259 ft gain and -25,259 ft loss. Surfaces skew 75% trail / 20% dirt road / 5% paved. Humid climbs, ridge exposure, and aid gaps in remote terrain. High point near 3,169 ft. Low near 390 ft. November temps run 50°F to 85°F. The course rewards patience early and punishes rushed descents after mile 33.
The Work
Train for 25,259 feet of climbing across 105 km. Back-to-back long runs on trail. Practice power-hiking grades above 15 percent. 30 hours total means limited margin: rehearse fueling every 45 to 60 minutes and downhill eccentric work weekly. Technicality 5/10. Build a block that simulates the crux near mile 42.
Kit
November in Japan: plan for 50°F to 85°F. Mandatory shell if rain is in forecast. Headlamp with spare batteries if 30 hours pushes past dark. Poles help on sustained climbs above mile 16. Vest capacity for 2 liters minimum. Shoes matched to 75% trail: lugs for mud, rock plate if the course turns technical after mile 33.
Race Day
Hold effort through mile 16. The field often splits on the first big climb after mile 33. Humid climbs, ridge exposure, and aid gaps in remote terrain near mile 42 is where time is won or lost. Walk the steep pinches. Run the flats and gentle downhills. Crew at major aids: socks, calories, ice if hot. Transitions under 5 minutes when possible. Final third is 22 miles of fatigue management. Finish with reserve for the last descent.
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