Races

Aso Volcano Trail

JapanMay

Japan, May. 115 km on 75% trail. +1,913 ft of climbing. 28 hours cutoff.

71 mi+1,913 ft-1,913 ft28 hours56 ft to 121 fttech 5/10Checkpoints per race bookWSER qualifierMay
Distance71 mi
Gain+1,913 ft
Loss-1,913 ft
Altitude56 ft to 121 ft
Technicality5/10
Air50°F to 85°F
Gradient profileOfficial race GPX
  • Start66 ft
  • High121 ft
  • Low56 ft
  • Finish66 ft

Geometryderived

Steepest drop66 ft-0.6% over 2.1 mi
Night miles26 misunset near 19:00 local

Weather at the cruxderived

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. +1,913 ft gain and -1,913 ft loss. Surfaces skew 75% trail / 20% dirt road / 5% paved. Humid climbs, ridge exposure, and aid gaps in remote terrain. High point near 121 ft. Low near 56 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 1,913 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.

Aso Volcano Trail