Shigehiro (井坂誠博) Isaka
ID 637477
Born : 1968 Cat. M55 Ultrarunner since 2014 JPN
29
DUV-index ?Largest integer N such that the runner has at least N credited races of at least N km.
36
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
40,0%
Rank quotient ?This runner's calculation uses 29 eligible race(s): Σ(rank − 1) = 4 164; Σ finishers = 10 407. 4 164 / 10 407 × 100 = 40.01%. A win adds 0 to the numerator. Lower is better.

Totals

Ultras completed29
Km — ultra races1 881 km
Longest race100,0 km
8th Ibaraki 100k Ultra Marathon — 8/3/2026

Km per year (ultra races)

330
5 races
2022
50
1 race
2023
148
2 races
2024
50
1 race
2025
208
3 races
2026

Race types (share of distance)

Road31,9%
Trail68,1%

Records

50 km5h54'18100 km9h53'48

HISTORY

29 race(s)
DateRacePerf.Rk
2026
14.06 63km JPN12th Echigo Country Trail 10:20:20 h107
26.04 45km JPN19th Ishioka Trail Run 5:59:15 h118
08.03 100km JPN8th Ibaraki 100k Ultra Marathon 11:15:15 h220
2025
21.09 50km JPN12th Tsukuba Renjyo 50 km Road & Trail Run 7:38:42 h89
2024
25.08 48km JPN11th Tsukuba Renjyo 48 km Road & Trail Run 7:57:37 h127
10.03 100km JPN6th Ibaraki 100k Ultra Marathon 9:53:48 h69
2023
29.04 50km JPN16th Ishioka Trail Run 7:48:26 h167
2022
28.08 75km JPN9th Tsukuba Renjyo 70 km Road & Trail Run 11:34:34 h87
19.06 60km JPN8th Echigo Country Trail 10:39:21 h119
27.05 45km JPN1st Karuizawa Trail Running Race 8:14:08 h210
29.04 50km JPN15th Ishioka Trail Run 6:44:33 h89
13.03 100km JPN4th Ibaraki 100k Ultra Marathon 12:49:21 h201
2021
25.04 50km JPN14th Ishioka Trail Run 5:54:18 h82
2020
18.10 54km JPN7th Shigakogen Extreme Trail 9:54:40 h169
2019
11.08 50km JPN1st OSJ Mahirusanchi Trail 50K 9:30:40 h86
23.06 72.6km JPN6. Spatrail - Shima to Kusatsu 72K 10:59:46 h186
09.06 100km JPN8th Hida Takayama 100 km Ultramarathon 11:36:30 h527
28.04 49km JPN12th Ishioka Trail Run 5:36:14 h42
24.03 100km JPN1st Ibaraki 100k Ultra Marathon 10:20:53 h135
2018
17.06 100km JPN2nd Nikko 100km Ultramarathon 11:29:37 h229
2017
27.05 50km JPN9th OSJ Okukuji Trail 50k 13:15:40 h291
2016
28.08 70km JPN3rd Tsukuba Renjyo 70 km Road & Trail Run 10:27:53 h132
16.07 65km JPN7th Nozawa Onsen 4100D Mountain Trail 11:47:29 h133
28.05 50km JPN8th OSJ Okukuji Trail 50k 11:46:06 h148
29.04 49km JPN9th Ishioka Trail Run 5:36:12 h37
2015
13.09 50km JPN8th OSJ Adatara Trail 50K 9:17:52 h61
30.08 70km JPN2nd Tsukuba Renjyo 70 km Road & Trail Run 9:10:01 h65
19.07 65km JPN6th Nozawa Onsen 4100D Mountain Trail 11:20:40 h87
2014
07.09 50km JPN7th OSJ Adatara Trail 50K 11:24:29 h180