Races
Aso Volcano Trail
Japan, May. 115 km on 75% trail. +18,875 ft of climbing. 28 hours cutoff.
- Start1,578 ft
- High3,944 ft
- Low1,454 ft
- Finish1,765 ft
- Japan at mile 0.0
- Aso Volcano Trail mile 14 at mile 14, cutoff 5.6000000000000005 hours
- Aso Volcano Trail mile 28 at mile 28, cutoff 11.200000000000001 hours
- Aso Volcano Trail mile 43 at mile 43, cutoff 16.8 hours
- Aso Volcano Trail mile 57 at mile 57, cutoff 22.400000000000002 hours
- Finish Japan at mile 71, cutoff 28 hours
Geometrycourse math
Weather at the cruxcourse math
At hour 6 of race, feels like 25 C (77 F).Sample of 7 race days, medium confidence.At hour 6 of race, apparent temperature P90 is 25 C / 78 F.
The cruxHumid climbs, ridge exposure, and aid gaps in remote terrain (near mile 46)
Course DNA
The Course
Aso Volcano Trail runs 115 km through Japan. +18,875 ft gain and -18,688 ft loss. Surfaces skew 75% trail / 20% dirt road / 5% paved. Humid climbs, ridge exposure, and aid gaps in remote terrain. High point near 4,012 ft. Low near 1,440 ft. May temps run 50°F to 85°F. The course rewards patience early and punishes rushed descents after mile 36.
The Work
Train for 18,875 feet of climbing across 115 km. Back-to-back long runs on trail. Practice power-hiking grades above 15 percent. 28 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 46.
Kit
May in Japan: plan for 50°F to 85°F. Mandatory shell if rain is in forecast. Headlamp with spare batteries if 28 hours pushes past dark. Poles help on sustained climbs above mile 18. Vest capacity for 2 liters minimum. Shoes matched to 75% trail: lugs for mud, rock plate if the course turns technical after mile 36.
Race Day
Hold effort through mile 18. The field often splits on the first big climb after mile 36. Humid climbs, ridge exposure, and aid gaps in remote terrain near mile 46 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 24 miles of fatigue management. Finish with reserve for the last descent.
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