Masakazu (大林正和) Obayashi
ID 221284
Born : 1971 Cat. M55 Ultrarunner since 2011 JPN
27
DUV-index ?Largest integer N such that the runner has at least N credited races of at least N km.
50
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
27,5%
Rank quotient ?This runner's calculation uses 27 eligible race(s): Σ(rank − 1) = 9 729; Σ finishers = 35 336. 9 729 / 35 336 × 100 = 27.53%. A win adds 0 to the numerator. Lower is better.

Totals

Ultras completed27
Km — ultra races2 787 km
> 100 km8
Longest race120,0 km
36th Fuji 5 Lakes Sparta Challenge — 19/4/2026

Km per year (ultra races)

218
2 races
2022
200
2 races
2023
2024
120
1 race
2025
120
1 race
2026

Race types (share of distance)

Road76,6%
Trail23,4%

Records

100 km8h40'05

HISTORY

27 race(s)
DateRacePerf.Rk
2026
19.04 120km JPN36th Fuji 5 Lakes Sparta Challenge 14:47:58 h314
2025
20.04 120km JPN35th Fuji 5 Lakes Sparta Challenge 14:54:30 h412
2023
25.06 100km JPN38. Lake Saroma 100 km Ultramarathon 12:13:41 h1128
11.06 100km JPN11th Hida Takayama 100 km Ultramarathon 11:49:29 h388
2022
22.05 100km JPN28th Yatsugatake Nobeyama 100 km 12:53:39 h460
17.04 118km JPN32th Fuji 5 Lakes 118 km Challenge 12:54:35 h96
2019
30.06 100km JPN34. Lake Saroma 100 km Ultramarathon 12:24:27 h1599
21.04 118km JPN29th Fuji 5 Lakes 118 km Challenge 14:11:54 h262
2018
24.06 100km JPN33. Lake Saroma 100 km Ultramarathon 11:25:15 h1000
22.04 118km JPN28th Fuji 5 Lakes 118 km Challenge 14:43:55 h385
2017
25.06 100km JPN32. Lake Saroma 100 km Ultramarathon 9:39:07 h266
2016
16.07 100km JPN9th OSJ Ontake 100km Ultra Trail 13:27:37 h210
26.06 100km JPN31. Lake Saroma 100 km Ultramarathon 9:35:27 h311
22.05 100km JPN22nd Yatsugatake Nobeyama 100 km 10:52:25 h156
24.04 118km JPN26th Fuji 5 Lakes 118 km Challenge 12:12:41 h97
2015
18.07 100km JPN8th OSJ Ontake 100km Ultra Trail 13:47:42 h196
28.06 100km JPN30. Lake Saroma 100 km Ultramarathon 9:43:33 h385
2014
30.08 63km JPN1st Shigakogen Extreme Trail 18:42:47 h252
29.06 100km JPN29. Lake Saroma 100 km Ultramarathon 11:55:00 h803
26.04 88km JPN3rd Shizuoka to Yamanashi 17:43:49 h115
2013
13.07 100km JPN6th OSJ Ontake 100km Ultra Trail 13:55:09 h177
30.06 100km road race JPN28. Lake Saroma 100 km Ultramarathon 9:37:56 h225
19.05 100km JPN19th Yatsugatake Nobeyama 100 km 11:29:57 h199
2012
24.06 100km road race JPN27. Lake Saroma 100 km Ultramarathon 8:40:05 h84
22.04 112km JPN22nd Fuji 5 Lakes 112 km Challenge 10:41:52 h33
2011
26.06 100km road race JPN26. Lake Saroma 100 km Ultramarathon 9:14:52 h142
30.04 112km JPN21st Fuji 5 Lakes 112 km Challenge 11:29:59 h61