Runners start · local time — (full marathon) / 08:20(half marathon) / 09:00(10km marathon)
The 16th Izu Oshima Marathon takes place on Saturday, December 5, 2026, in Oshima, Tokyo.
Every race starts in front of the Motomachi Port passenger terminal and finishes back at the same spot.
Start times are 8 a.m. for the full marathon, 8:20 a.m. for the half marathon,
and 9 a.m. for the 10K, with a time limit of 7 hours, 3 hours, and 1 hour 40 minutes, respectively.
The full marathon course makes one loop of the island on the Izu Oshima ring road.
Past 10K, heading toward Oshima Park, comes the toughest stretch, with steep climbs and descents.
The route passes through a tunnel of camellia trees and alongside Urasabaku, the volcanic desert behind Mount Mihara, and there are two more hills after 30K.
The gap between the highest and lowest points is 365 meters, with 785 meters of total climbing.
Full marathon cutoffs are 10 a.m. outside Oshima Park (13.0 km), 12:30 p.m. at Habu Miharashidai (27.5 km),
and 1 p.m. outside the Sashikiji agricultural co-op (31.0 km).
The half marathon and 10K run on the Sunset Palm Line, a coastal road with views across the water to the Izu Peninsula and Mount Fuji.
The half marathon goes out and back on it twice, the 10K once (26 meters of elevation change).
The half marathon has a 10:30 a.m. cutoff at 11K, outside Hamanoyu.
In 2025, there was an aid station about every 5K, staffed by island residents.
Every finisher gets a medal, and after the finish there's arajiru, a hot soup made from fish bones,
plus a ticket to Hamanoyu, an open-air hot spring overlooking the ocean.
