Tomokazu (井原知一) Ihara
ID 161561
Born : 1977 Cat. M45 Ultrarunner since 2009 JPN
70
DUV-index ?Largest integer N such that the runner has at least N credited races of at least N km.
80
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
7
Countries visited ?HKGHong KongINAIndonesiaITAItalyJPNJapanTHAThailandTPETaiwanUSAUnited States
8,6%
Rank quotient ?This runner's calculation uses 89 eligible race(s): Σ(rank − 1) = 1 744; Σ finishers = 20 166. 1 744 / 20 166 × 100 = 8.65%. A win adds 0 to the numerator. Lower is better.

Totals

Ultras completed89
Km — ultra races11 667 km
> 100 km60
> 160 km53
> 200 km3
> 24h1
Longest race298,0 km
12th Hong Kong Four Trails Ultra Challenge — 21/1/2023

Km per year (ultra races)

1 006
7 races
2022
1 344
9 races
2023
1 036
8 races
2024
695
5 races
2025
373
3 races
2026

Race types (share of distance)

Trail97,6%
Elim.2,4%

Wins & podiums (ultra)

🏆 Win7
🏆 Win M7
🏅 Top 320
🏅 Top 3 M20
Longest winning streak1
Current streak0

Records

50 km5h13'30100 km9h55'1750 mi13h29'16100 mi16h52'59Backyard42 loops

HISTORY

89 race(s)
DateRacePerf.Rk
2026
18.07 50km USA18th Silverton Alpine 50K 5:25:14 h11
02.05 162km INA12th Mt Rinjani Ultra - 162km 46:21:30 h5
17.01 100mi USA26th HURT 100 Endurance Run 100 Mile 26:09:26 h11
2025
06.12 48km THA2nd Chiangmai Thailand by UTMB - HMONG 50-DAY 6:14:18 h69
10.10 169km JPN5th Lake Biwa 100 28:05:08 h6
25.08 153km ITA15ème Sur les Traces des Ducs de Savoie 31:26:51 h271
18.07 102mi USA12th Ouray 100 Mile Endurance Run 32:40:54 h5
17.05 100mi USA31st Massanutten Mountain Trails 100 Mile 23:16:43 h7
2024
06.12 175km THA1st Chiangmai Thailand by UTMB - TRANS-INT 160 28:45:30 h23
16.11 100mi JPN10th FunTrails100M Round 24:42:22 h1 🏆
14.09 100mi USA23st Plain 100 Mile Endurance Run 25:54:00 h2 🥈
21.06 165km JPN3rd Deep Japan Ultra 100 - 165 km 28:56:32 h3 🥉
08.06 52.4km JPN4th Okushinano 100 - 50 km 6:19:04 h26
18.05 100mi USA30th Massanutten Mountain Trails 100 Mile 24:06:09 h15
20.03 40mi USA29th The Barkley Marathons 40 Mile 22:08:53 h11
20.03 60mi USA29th The Barkley Marathons 60 Mile Fun Run 34:43:15 h10
2023
28.10 80km JPN3rd Manno Mountain Madness 2023 13:29:16 h7
08.09 100mi USA44th Wasatch Front 100 Mile 23:17:17 h6
20.08 100mi USA41st Leadville Trail 100 Mile 23:31:18 h40
15.07 100mi USA3rd Devil's Gulch 100 Mile Race 23:54:44 h1 🏆
24.06 100mi USA50th Western States 100 Mile Endurance Run 20:19:59 h39
03.06 100mi USA45th Old Dominion 100 Mile Endurance Run 18:52:27 h2 🥈
15.03 40mi USA28th The Barkley Marathons 40 Mile 22:46:38 h11
15.03 60mi USA28th The Barkley Marathons 60 Mile Fun Run 35:55:24 h8
21.01 298km HKG12th Hong Kong Four Trails Ultra Challenge 2d 06:02:00 h1 🏆
2022
09.12 171km THA3rd Thailand by UTMB - 100mi 29:19:12 h22
19.11 Backyard Ultra JPN3rd Last Samurai Standing Backyard Ultra - Tokyo 281.652 km (42h)1 🏆
17.09 162.6km JPN14th Shinetsu Five Mountains Trail 100 mile 20:56:58 h3 🥉
17.07 65km JPN13th Nozawa Onsen 4100D Mountain Trail 8:34:17 h14
11.06 100.8km JPN2nd Okushinano 100 12:04:38 h15
21.05 100mi JPN7th Trainic World 100 Mile in Sai-No-Kuni 26:24:41 h2 🥈
08.03 40mi USA27th The Barkley Marathons 40 Mile 26:15:27 h1 🏆
2021
28.08 75km JPN1st Okushinano 100 - 75 km 9:03:39 h25
2020
18.01 100mi USA20th HURT 100 Endurance Run 100 Mile 23:57:21 h4
2019
30.11 75km TPE4th Formosa Trail 75km 11:06:59 h5
14.09 100mi JPN11th Shinetsu Five Mountains Trail 100 mile 20:20:18 h4
03.08 50km USA8th Volcanic 50 6:46:37 h11
13.07 100mi JPN12th OSJ Ontake 100 Mile Ultra Trail 19:13:17 h6
30.03 60mi USA24th The Barkley Marathons 60 Mile Fun Run 39:38:34 h4
06.02 298km HKG8th Hong Kong Four Trails Ultra Challenge 2d 09:42:00 h2 🥈
19.01 100mi USA19th HURT 100 Endurance Run 100 Mile 24:21:19 h4
2018
01.12 104km TPE3rd Formosa Trail 100km 15:29:53 h5
15.09 100mi JPN10th Shinetsu Five Mountains Trail 100 mile 21:02:41 h7
14.07 65km JPN9th Nozawa Onsen 4100D Mountain Trail 9:16:17 h6
2017
23.09 100mi USA5th Mountain Lakes 100 21:14:41 h5
16.09 50km USA4th The Barkley Fall Classic 9:55:23 h3 🥉
15.07 100mi JPN10th OSJ Ontake 100 Mile Ultra Trail 19:07:10 h9
11.03 100mi USA3rd Coyote Cohorts Backbone 100 Mile Trail Ultra 21:47:13 h1 🏆
14.01 100mi USA17th HURT 100 Endurance Run 100 Mile 25:43:23 h6
2016
17.09 100mi USA5th Idaho Mountain Trail Ultra Festival (IMTUF 100) 26:23:29 h13
27.08 100mi USA18th Cascade Crest Classic 100 Mile 21:37:00 h8
06.08 100mi USA29th Angeles Crest 100 Mile 25:43:09 h28
19.03 100mi USA5th Fort Clinch 100 Mile Endurance Run 19:23:20 h2 🥈
19.02 100mi USA1st Orcas Island 100 Mile Race 22:42:40 h3 🥉
16.01 100mi USA16th HURT 100 Endurance Run 100 Mile 25:44:33 h8
2015
25.09 170.3km JPN4th Ultra-Trail Mt. Fuji 25:24:59 h15
18.07 100mi JPN8th OSJ Ontake 100 Mile Ultra Trail 17:55:38 h4
17.01 100mi USA15th HURT 100 Endurance Run 100 Mile 23:21:07 h4
2014
14.09 110km JPN6th Shinetsu Five Mountains Trail 110km 11:41:11 h9
02.08 100mi USA27th Angeles Crest 100 Mile 31:19:27 h74
21.03 100mi USA9th Antelope Island Buffalo Run 100 Mile 17:17:12 h2 🥈
18.01 100mi USA14th HURT 100 Endurance Run 100 Mile 26:02:00 h7
2013
30.11 168km HKGHK168 - 168 km ultra-endurance race Hong Kong 27:25:30 h3 🥉
02.11 100mi USA6th Pinhoti 100 Mile 20:30:03 h9
15.09 110km JPN5th Shinetsu Five Mountains Trail 110km 12:10:23 h10
03.08 100mi USA26th Angeles Crest 100 Mile 22:28:35 h5
22.03 100mi USA8th Antelope Island Buffalo Run 100 Mile 17:47:00 h4
19.01 100mi USA13th HURT 100 Endurance Run 100 Mile 24:49:00 h6
2012
17.11 100mi USA4th The Chimera 100 Mile Mountain Race 20:09:21 h5
15.07 100mi JPN5th OSJ Ontake 100 Mile Ultra Trail 17:06:31 h2 🥈
19.05 100mi USA2nd Born to Run Ultra 100 Mile Marathon 17:50:00 h1 🏆
24.02 100mi USA3rd Rocky Road 100 Mile Runs 16:52:59 h4
2011
19.11 100mi USA3rd The Chimera 100 Mile Mountain Race 19:30:33 h3 🥉
06.11 50km JPN3rd Kanna Mountain Run II 6:35:19 h7
09.10 71.5km JPN19th Hasetsune Cup - Japan Mountain Endurance Race 9:55:17 h62
24.09 110km JPN3rd Shinetsu Five Mountains Trail 110km 12:22:49 h10
16.07 100mi JPN4th OSJ Ontake 100 Mile Ultra Trail 18:49:51 h4
05.06 50km JPN3rd OSJ Okukuji Trail 50k 7:36:52 h20
2010
10.10 71.5km JPN18th Hasetsune Cup - Japan Mountain Endurance Race 9:53:11 h54
03.10 50km JPN4th Madarao Forest Trails 50km 5:13:30 h11
19.09 110km JPN2nd Shinetsu Five Mountains Trail 110km 13:00:13 h8
04.07 50km JPN2nd OSJ Shiga Kogen Trail 50K 7:25:19 h21
16.05 100km JPN16th Yatsugatake Nobeyama 100 km 9:55:17 h68
11.04 50km JPN2nd OSJ Okukuji Trail 50k 8:58:44 h17
2009
04.10 50km JPN3rd Madarao Forest Trails 50km 5:41:54 h27
19.07 100km JPN2nd OSJ Ontake 100km Ultra Trail 14:10:16 h113
05.07 50km JPN1st OSJ Shiga Kogen Trail 50K 9:08:30 h159
12.04 50km JPN1st OSJ Okukuji Trail 50k 12:12:38 h111
08.02 50km JPN1st OSJ Jungle Trail 50K Amami 8:01:32 h156