Races
OSJ Ontake
Japan, July. 100 mi on 75% trail. +28,573 ft of climbing. 24 hours cutoff.
- Start2,969 ft
- High5,567 ft
- Low2,881 ft
- Finish2,969 ft
- Japan at mile 0.0
- OSJ Ontake mile 20 at mile 20, cutoff 4.800000000000001 hours
- OSJ Ontake mile 40 at mile 40, cutoff 9.600000000000001 hours
- OSJ Ontake mile 60 at mile 60, cutoff 14.399999999999999 hours
- OSJ Ontake mile 80 at mile 80, cutoff 19.200000000000003 hours
- Finish Japan at mile 100, cutoff 24 hours
Geometrycourse math
The cruxHumid climbs, ridge exposure, and aid gaps in remote terrain (near mile 65)
Course DNA
The Course
OSJ Ontake runs 100 mi through Japan. +28,573 ft gain and -28,573 ft loss. Surfaces skew 75% trail / 20% dirt road / 5% paved. Humid climbs, ridge exposure, and aid gaps in remote terrain. High point near 5,591 ft. Low near 2,844 ft. July temps run 50°F to 85°F. The course rewards patience early and punishes rushed descents after mile 50.
The Work
Train for 28,573 feet of climbing across 100 mi. Back-to-back long runs on trail. Practice power-hiking grades above 15 percent. 24 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 65.
Kit
July in Japan: plan for 50°F to 85°F. Mandatory shell if rain is in forecast. Headlamp with spare batteries if 24 hours pushes past dark. Poles help on sustained climbs above mile 25. Vest capacity for 2 liters minimum. Shoes matched to 75% trail: lugs for mud, rock plate if the course turns technical after mile 50.
Race Day
Hold effort through mile 25. The field often splits on the first big climb after mile 50. Humid climbs, ridge exposure, and aid gaps in remote terrain near mile 65 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 33 miles of fatigue management. Finish with reserve for the last descent.
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