BOOSTランニングフェスタ in 味の素スタジアム ナイトソロマラソン 2026

BOOST Running Festa at Ajinomoto Stadium Night Solo Marathon is an evening summer run inside Ajinomoto Stadium in Chofu, Tokyo. The solo races are 5 km and 10 km, with runners starting after check-in in the early evening, and the wider event also includes a half-distance relay for teams. It was added because Tokyo has very few running events in the hottest part of summer, even though plenty of people still want a race to enter. The course uses 1 km laps, so the format is simple to understand and manageable for newer runners. Relay teams can choose each runner’s distance, number of laps, and running order, which makes it work for mixed groups such as families, coworkers, beginners, and stronger runners sharing one team. The organizers build the event around heat control: participants can use a cooler room after running, and the venue also provides cold water showers, mist, and hydration points. Spectators can come without registration, so it works as a small stadium night event as much as a race.