It was a high-level men's race at this year's Lake Saroma 100 km Ultramarathon. In cooler conditions than usual at Lake Saroma Tatsuya Inagaki and Masato Tanaka went out hot with a 34:50 opening 10 km, way ahead of pace for Alexsandr Sorokin's 6:05:35 WR and even the unofficial 5:59:20 run by Sibusiso Kubheka last year. Tanaka lost touch with Inagaki before 40 km, but with halfway splits of 2:54:59 and 2:56:05 both were still far under Kubheka's mark. Running 3rd through 5th at that point, Chiharu Kuzukubo, Hirofumi Nakamura and Toru Somiya were all under Sorokin's WR pace too, with 6th-placer Takatoshi Oe just off in 3:02:49.
Inagaki couldn't sustain that kind of performance, and by 60 km Tanaka was back in touch. 10 km Tanaka was 5 minutes ahead and still on 5:54:46 pace, with Oe moving up to 3rd and just over 3 minutes behind Inagaki. 70 km is the marathon's 30 km of the 100 km, and Tanaka began to slow rapidly, over 6 hour pace at 80 km with Oe now in 2nd and 5 minutes back, then on 6:07 pace at 90 km with only a 1:19 lead over Oe and even Tanaka regaining ground. In the end Tanaka could't hold Oe off, Oe winning in 6:10:23 with Tanaka next in 6:12:19 and Inagaki 3rd in 6:16:02. In 4th, Somiya cleared 6:20 too with a 6:19:46, making it one of the deepest years in Lake Saroma history.
The women's race started off as a head-to-head between last year's winner Mikiko Ota and Akiko Maruichi, the pair running together for the first 20 km before Ota opened a lead. But between 40 and 50 km Ota started to fade, and Maruichi went from a minute and a half behind to 10 minutes ahead. Ota started to turn it around over the last 30 km, but in the end Maruichi kept a margin of almost 7 minutes to win in 7:22:23. Ota was next in 7:28:50, with Ako Takigahira 3rd in 7:42:47.
Based on their performances here, post-race the JAU named Oe, Tanaka and Inagaki to the Japanese men's team for September's IAU 100 km World Championships in Ames, Spain alongside NR holder Jumpei Yamaguchi, with Somiya named alternate. Maruichi, Ota and Takigahira join Miho Nakata on the women's team, 4th-placer Ono named alternate.
Mahiro Watanabe won the men's 50 km in 3:07:58, with Hong Kong's Virginia Lo winning the women's title by almost 33 minutes in an excellent 3:22:52.
41st Lake Saroma Ultramarathon
Hokkaido, 28 June 2026
Men's 100 km
1. Takatoshi Oe - 6:10:23
2. Masato Tanaka - 6:12:19
3. Tatsuya Inagaki - 6:16:02
4. Toru Somiya - 6:19:46
5. Hirofumi Nakamura - 6:22:04
6. Shun Masaoka - 6:38:18
7. Shinji Watanabe - 6:39:41
8. Takahiro Sakaguchi - 6:42:03
9. Takayuki Kibata - 6:43:09
10. Fumio Shimura - 6:45:58
Women
1. Akiko Maruichi - 7:22:23
2. Mikiko Ota - 7:28:50
3. Ako Takigahira - 7:42:47
4. Kaoruko Ono - 7:44:15
5. Saki Shimada - 7:50:43
6. Haruka Yamaguchi - 7:54:41
7. Yuka Tomitaka - 7:59:12
8. Kanako Tomita - 8:03:33
9. Yukari Kiyomiya - 8:08:53
10. Emi Saito - 8:25:34
Men's 50 km
1. Mahiro Watanabe - 3:07:58
2. Daichi Soda - 3:09:14
3. Yasuhiko Shibata - 3:10:33
Women's 50 km
1. Virginia Lo (Hong Kong) - 3:22:52
2. Yoshimi Kishi - 3:55:33
3. Ikuko Hasegawa - 4:02:58

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