Hiroki (荒井大樹) Arai
ID 169803
Born : 1981 Cat. M45 Ultrarunner since 2009 JPN
37
DUV-index ?Largest integer N such that the runner has at least N credited races of at least N km.
53
DUV-index+ ?Largest integer N such that the race distances provide at least N complete segments of N km in total. A single long race may therefore contribute several segments. See the DUV-Index tab for the detailed calculation. calculation details
1
Countries visited ?JPNJapan
4,3%
Rank quotient ?This runner's calculation uses 37 eligible race(s): Σ(rank − 1) = 638; Σ finishers = 14 737. 638 / 14 737 × 100 = 4.33%. A win adds 0 to the numerator. Lower is better.

Totals

Ultras completed37
Km — ultra races3 573 km
> 100 km12
> 160 km2
> 200 km2
> 24h2
Longest race230,1 km
21. Hiratsuka 24 hour race — 15/9/2018

Km per year (ultra races)

284
3 races
2022
2023
75
1 race
2024
2025
66
1 race
2026

Race types (share of distance)

Road100,0%

Wins & podiums (ultra)

🏆 Win9
🏆 Win M11
🏅 Top 321
🏅 Top 3 M22
Longest winning streak2
Current streak1

Records

6 h84,38 km24 h230,10 km

HISTORY

37 race(s)
DateRacePerf.Rk
2026
17.01 5h JPN13th Iikoto Challenge - 5h 65.672 km1 🏆
2024
14.01 5h JPN11th Iikoto Challenge - 5h 75.224 km2 🥈
2022
03.07 8h JPN28th 8-Hour Endurance Race Tokorozawa 88.200 km3 🥉
05.06 78km JPN29. Ultramarathon Okumusashi 5:47:56 h3 🥉
17.04 118km JPN32th Fuji 5 Lakes 118 km Challenge 10:38:56 h10
2019
02.06 78km JPN26. Ultramarathon Okumusashi 6:05:51 h10
21.04 118km JPN29th Fuji 5 Lakes 118 km Challenge 9:44:12 h7
03.02 5h JPN9th Iikoto Challenge - 5h 71.410 km1 🏆
2018
15.09 24h JPN21. Hiratsuka 24 hour race 230.100 km3 🥉
30.06 8h JPN24th 8-Hour Endurance Race Tokorozawa 88.200 km1 🏆
03.06 78km JPN25. Ultramarathon Okumusashi 6:09:13 h7
22.04 118km JPN28th Fuji 5 Lakes 118 km Challenge 9:22:53 h3 🥉
2017
09.09 6h JPN20. Hiratsuka 6 hour race 81.310 km1 🏆
02.07 8h JPN23th 8-Hour Endurance Race Tokorozawa - 3 tai 90.888 km1 🏆
04.06 78km JPN24. Ultramarathon Okumusashi 6:00:56 h7
23.04 118km JPN27th Fuji 5 Lakes 118 km Challenge 9:29:36 h5
09.01 6h JPN7th Iikoto Challenge - 6h 84.384 km2 🥈
2016
24.09 6h JPN19. Hiratsuka 6 hour race 83.040 km2 🥈
03.07 8h JPN22th 8-Hour Endurance Race Tokorozawa - 3 tai 87.642 km1 🏆
05.06 78km JPN23. Ultramarathon Okumusashi 5:57:47 h13
24.04 118km JPN26th Fuji 5 Lakes 118 km Challenge 9:46:43 h5
11.01 6h JPN6th Iikoto Challenge - 6h 82.800 km1 🏆
2015
19.09 6h JPN18. Hiratsuka 6 hour race 77.850 km2 🥈
22.06 77km JPN22. Ultramarathon Okumusashi 5:56:57 h11
19.04 118km JPN25th Fuji 5 Lakes 118 km Challenge 10:38:48 h11
2014
13.09 6h JPN17. Hiratsuka 6 hour race 77.850 km2 🥈
20.04 108km JPN24th Fuji 5 Lakes 108 km Challenge 11:07:58 h69
2013
14.09 6h JPN16. Hiratsuka 6 hour race 72.660 km3 🥉
2012
01.09 6h JPN15. Hiratsuka 6 hour race 77.850 km4
2011
15.10 24h JPN6th Jingu Gaien 24 Hour Challenge 213.976 km13
24.09 6h JPN14. Hiratsuka 6 hour race 79.580 km1 🏆
11.06 6h JPN10. Tokyo Challenge 6 hours 78.419 km2 🥈
30.04 112km JPN21st Fuji 5 Lakes 112 km Challenge 9:59:59 h12
2010
11.10 6h JPN13. Hiratsuka 6 hour race 74.800 km1 🏆
19.06 6h JPN9. Tokyo Challenge 6 hours 72.100 km2 🥈
25.04 112km JPN20th Fuji 5 Lakes 112 km Challenge 14:26:06 h326
2009
26.04 112km JPN19th Fuji 5 Lakes 112 km Challenge 13:28:24 h127