Ecomarathon de Saïko 2026

The Ecomarathon de Saiko is a road race held in October in Saitama Prefecture, Japan. It begins at Sai Lake within Toda’s Saiko Doman Green Park. Participants can select a half marathon, a 10 km run, or a 5 km parent-child fun run. The event has a limit of 500 participants. The half marathon and 10 km are open to healthy runners aged 15 and older, and the 5 km is for children under 15 accompanied by a parent. All three races follow loop courses within the park, keeping runners near the lake, ponds, and green areas instead of on city streets. The event has an environmental focus and includes sponsors and cooperators such as Alishan, Second Harvest, the International Refugee Support Association, and PEACE RUN. Participants receive a prize, but they must manage their own belongings as luggage storage is not available.