Guide2026 TransJeju 100K Sub-19-Hour Race Plan and CP Times
My 2026 TransJeju 100K plan: start at 5:00 AM, aim for a 23:30 finish, and keep 29 minutes in reserve. Includes target CP times and post-Seongpanak strategy.
My goal for the 2026 TransJeju 100K is to start at 5:00 AM and finish before the date changes. Instead of aiming for 23:59, my target finish time is 23:30. The remaining 29 minutes are reserved for problems that may arise during the race.
Dividing the full distance by the target time does not produce a useful pace for a trail race longer than 100km. A kilometer around Yeongsil, Eorimok, Gwaneumsa, or Seongpanak can take very different amounts of time from a kilometer through the forests later in the course. Several accounts from the 2025 race also describe runners slowing after Seongpanak because of mud, wet rocks, stream crossings, darkness, and accumulated fatigue.
Using the 2025 course, official results, and runners' accounts, I built this 18-hour-30-minute checkpoint plan.
This is not an official pace chart or an average of runners' 2025 splits. The checkpoint distances and course sequence come from 2025 sources, while the target times are my personal plan for finishing before midnight in 2026. Weather and trail conditions can change the difficulty significantly.
Official 2026 TransJeju 100K information
The official Jeju100K page listed the following information as of September 9, 2026.
| Item | Details |
|---|---|
| Race date | Saturday, October 3, 2026 |
| Start time | 05:00 |
| Start and finish | Jeju World Cup Stadium |
| Distance | 104km |
| Elevation gain | 4,000m+ |
| Time limit | 29 hours |
| Personal target | Finish at 23:30 in 18 hours 30 minutes |
The race details and mandatory equipment are available on the official 2026 TransJeju Jeju100K page. The official rules also state that poles are prohibited throughout the course.
Why I chose 23:30
Starting at 5:00 AM means I need to finish in under 19 hours to arrive before midnight.
In the official 2025 ITRA results, 175th-place Hongkyu Lee finished in 18:58:18. With a 5:00 AM start, that is 23:58:18. The next runner, Jaeeun Cho in 176th place, finished in 19:01:55, or 00:01:55 the following day.
Midnight falls between those two results. Thirty runners finished between 18:30 and 18:58, placing their actual arrival times between 23:30 and 23:58.
A plan targeting 18:59 leaves no room for delays. A few extra minutes at each aid station, cramps, or a slower pace over rocks at night can easily cost half an hour. I therefore separated my planned finish from the final deadline.
| Target | Time | Purpose |
|---|---|---|
| Planned finish | 23:30 | Arrival time if the race goes to plan |
| Emergency reserve | 23:30–23:59 | Aid-station delays, pain, or slower night running |
| Final deadline | Before 23:59 | Finish before the date changes |
18-hour-30-minute checkpoint schedule
This schedule uses checkpoint locations described in accounts of the 2025 race. I will confirm every location and distance against the final 2026 runner guide and GPX before race day.
| Point | Distance | Target time | Elapsed | Section time |
|---|---|---|---|---|
| START, Jeju World Cup Stadium | 0km | 05:00 | 0:00 | - |
| CP1, Healing Forest | 7km | 05:55 | 0:55 | 0:55 |
| CP2, Yeongsil | 20km | 08:20 | 3:20 | 2:25 |
| CP3, Eorimok | 28km | 09:55 | 4:55 | 1:35 |
| CP4, Gwaneumsa | 41km | 11:20 | 6:20 | 1:25 |
| CP5, Seongpanak | 59km | 15:50 | 10:50 | 4:30 |
| CP6, Eseungak Oreum | 71km | 17:40 | 12:40 | 1:50 |
| CP7, Camping Site | 82km | 19:55 | 14:55 | 2:15 |
| CP8, Healing Forest | 92km | 21:45 | 16:45 | 1:50 |
| FINISH, Jeju World Cup Stadium | 104km | 23:30 | 18:30 | 1:45 |
The plan does not use a constant average pace. I have allowed more time on Hallasan and plan to move steadily on the runnable sections. Time spent at aid stations is included in each section.
Yeongsil at 20km by 08:20
The first time to remember is 08:20 at Yeongsil, 3 hours 20 minutes after the start. Three actual 18-hour finishers in 2025 reached Yeongsil between 3:11 and 3:26, so I moved the original 08:00 target to a more realistic time.
I do not need to gain 10 or 20 minutes in the opening 20km by running every climb. Hallasan must still be crossed twice, and 20km is early in a 100K race. I plan to control my effort and keep eating and drinking on the way to Yeongsil.
Save the legs between Yeongsil and Eorimok
| Point | Target |
|---|---|
| Yeongsil, 20km | 08:20 |
| Eorimok, 28km | 09:55 |
| Section time | 1 hour 35 minutes |
I have allowed 1 hour 35 minutes for the 8km from Yeongsil, across Witse Oreum, and down to Eorimok. The three comparison runners covered this section in about 1:31–1:35. I want to stay within that range without chasing extra time and finish the first Hallasan crossing with usable legs.
During the recent Taebaek Trail 50K, I cramped above the knee while descending. That experience makes it risky to lengthen my stride and chase time on the descent to Eorimok. The hardest Gwaneumsa climb and another 45km after Seongpanak still remain.
How cramps at the Taebaek Trail 50K changed this plan
I entered the 2026 Dynafit Taebaek Trail 50K as a training race for TransJeju. The cramping that day did not happen only once.
My calves and shins tightened on the steep dirt climb up Taebaeksan. When they cramped, I let my friend go ahead and rested for about five minutes. I started moving again, but the cramps returned on the climb from Manhangjae toward the Hambaeksan entrance. After descending Hambaeksan, I cramped above the knee and had to alternate between walking and running.
The cramps returned on both climbs and descents during a 50K race. If the same thing happens at TransJeju, far more distance will remain. Pushing hard to gain 10 minutes can cost the rest period and reduce my pace on every runnable section afterward. This time, I plan to lower the effort as soon as the muscles begin to tighten rather than waiting for a full cramp.
| What happened at Taebaek | How I will respond at TransJeju |
|---|---|
| Calves and shins tightened on a steep climb | Do not run the Yeongsil and Gwaneumsa climbs to gain time |
| Cramps returned on the next climb after a short rest | Do not return immediately to the previous pace |
| Cramping above the knee after a long descent | Shorten my stride on the descents to Eorimok and Seongpanak |
| Alternating walking and running late in the race | Maintain an even effort instead of trying to recover time at full speed |
I completed Taebaek despite the cramps, but the same problem after 50km of a 100K would leave much farther to go. Arriving slightly late at Yeongsil or Gwaneumsa with functional legs is preferable. The 23:30 target should preserve my ability to keep moving, not encourage me to bank time early.
Gwaneumsa at 41km by 11:20
| Point | Target |
|---|---|
| Eorimok, 28km | 09:55 |
| Gwaneumsa, 41km | 11:20 |
| Section time | 1 hour 25 minutes |
I plan to move faster between Eorimok and Gwaneumsa and arrive at 11:20. The three comparison runners reached this point in 6:07–6:18. My plan uses 6 hours 20 minutes for the first 41km and leaves 12 hours 10 minutes for the remaining 63km.
In his 2025 race report, Anggriawan Sugianto described the road from Eorimok to Gwaneumsa as a long and difficult 12km stretch. Treating it as a recovery section just because the first major mountain section has ended could delay my arrival. If I preserve energy over the first Hallasan crossing, this is where I can manage time with a steady pace.
Allow 4 hours 30 minutes from Gwaneumsa to Seongpanak
| Point | Target |
|---|---|
| Gwaneumsa, 41km | 11:20 |
| Seongpanak, 59km | 15:50 |
| Section time | 4 hours 30 minutes |
I have assigned 4 hours 30 minutes to the 18km from Gwaneumsa, over Baengnokdam, and down to Seongpanak. That is an average of 15 minutes per kilometer. The three actual section times ranged widely, from about 4:17 to 4:54, so I moved time saved on the earlier road section back into this climb and descent.
Sugianto called Gwaneumsa to Seongpanak the hardest part of his race. His speed fell sharply on the long stair climb, and he experienced sharp pain in his inner thigh or groin. Trying to gain 20 minutes here could cost hours later.
At Gwaneumsa, I plan to take the supplies I need without sitting for too long. I will hold a steady effort uphill and descend conservatively enough to protect my quadriceps. The target is Seongpanak at 15:50.
Assessing the race at Seongpanak
| Arrival at Seongpanak | Time until midnight | Assessment |
|---|---|---|
| 15:30 | 8 hours 30 minutes | 20 minutes ahead; do not push harder |
| 15:45–16:00 | 8 hours–8 hours 15 minutes | On plan |
| 16:30 | 7 hours 30 minutes | Reduce unnecessary aid-station time and keep moving |
| 17:00 | 7 hours | The remaining 45km at night becomes very tight |
An arrival around 15:50 means I am on schedule. It does not mean that the race becomes easy once Hallasan is behind me. The accounts I found repeatedly describe plans unraveling after Seongpanak.
Comparing my target pace with three actual 2025 finishers
The first version of this schedule was an estimate based on the 2025 course flow and race reports. I later checked the official checkpoint splits on UTMB Live 2025 for one runner each from the low-18-hour, 18:30, and near-18:50 ranges.
The runners are 127th-place Donghyun Kim (18:08:51), 146th-place Vachira Tongrow (18:30:39), and 163rd-place Juwon Kang (18:48:43). Every value below is elapsed time from the 5:00 AM start.
| Point | Distance | Donghyun 18:08 | Vachira 18:30 | Juwon 18:48 | My 18:30 target |
|---|---|---|---|---|---|
| CP1, Healing Forest | 7km | 0:58 | 0:53 | 0:55 | 0:55 |
| CP2, Yeongsil | 20km | 3:27 | 3:12 | 3:19 | 3:20 |
| CP3, Eorimok | 28km | 4:59 | 4:43 | 4:54 | 4:55 |
| CP4, Gwaneumsa | 41km | 6:17 | 6:07 | 6:19 | 6:20 |
| CP5, Seongpanak | 59km | 10:44 | 10:34 | 11:13 | 10:50 |
| CP6, Eseungak Oreum | 71km | 12:34 | 12:17 | 13:14 | 12:40 |
| CP7, Camping Site | 82km | 14:54 | 14:45 | 15:27 | 14:55 |
| CP8, Healing Forest | 92km | 16:39 | 16:52 | 17:17 | 16:45 |
| FINISH | About 104km | 18:09 | 18:31 | 18:49 | 18:30 |
Three runners are not enough to establish an average pace chart, but they are useful for checking the allocation in my original plan. Its three-hour Yeongsil target was 12–27 minutes faster than all three actual runners, while its seven-hour Gwaneumsa target was 42–53 minutes slower. The distribution of time within the first 41km needed adjustment.
I therefore moved Yeongsil to 3:20 and aligned Eorimok at 4:55 and Gwaneumsa at 6:20 with the actual range. The Gwaneumsa-to-Seongpanak section varied substantially even among these three runners, from about 4:17 to 4:54. I assigned 4:30 to it, putting my Seongpanak target at 10:50 elapsed.
The fastest finisher of the three was not the first to Seongpanak. Vachira reached it ten minutes before Donghyun but took about 7:56 from there to the finish, compared with Donghyun's 7:25. Juwon took about 7:36. Even within the same broad finish-time range, runners distributed their effort differently.
Race flow observed in Run Juwon's video
I also watched a 2025 TransJeju 100K video by Run Juwon, a running YouTuber I follow. The video shows physical changes and intermediate points that official splits cannot. Some checkpoint times I transcribed from the video differ by several minutes from UTMB Live, so I used the official splits in the comparison table and kept the observations below only as race-strategy context.
| Point or situation observed in the video | Elapsed | Detail |
|---|---|---|
| 46km | 8:00 | During the second Hallasan crossing |
| 49km | 9:00 | Continuing the climb |
| Baengnokdam | 9:34 | Reached the summit |
| Descent to Seongpanak | - | Iliotibial-band pain; took pain relief at the CP |
| 72.5km | 13:11 | Reported running at roughly 7 min/km afterward |
| Around CP7 | 15:37 | Reported passing about 40 runners by this point |
| 94.3km | 17:15 | Did not walk after the final checkpoint |
Juwon was able to run strongly again despite pain on the descent to Seongpanak. According to the official record, the roughly 45km from Seongpanak to the finish took about 7:36. The lesson is not that one particular Seongpanak time guarantees a sub-19-hour finish.
I need to assess both my Seongpanak time and whether I still have legs capable of moving through the final 45km.
That is another reason to protect my legs on the early descents rather than simply banking time. These three results do not statistically prove my target schedule; they show that more than one pace distribution can produce an 18-hour-30-minute finish.
Why Seongpanak was not the end of the hard running
The elevation profile appears gentler after Seongpanak, but the ground was not necessarily runnable, and darkness made the same terrain harder.
“The easy-looking 12.8km took longer than planned”
Japanese runner Nozomi Sasaki, who finished in 20 hours 27 minutes, wrote in her 2025 race report that poor footing slowed her immediately after the 60km checkpoint. She had expected the next 12.8km to be easy from the elevation profile but arrived 12 minutes later than planned.
After that, mud grabbed at her feet in complete darkness. She crossed streams over slippery, moss-covered rocks several times. Her pace dropped badly between CP6 and CP7, and after roughly 16 hours she began to feel sleepy and developed pain throughout her legs.
Her experience shows why the 12km after Seongpanak cannot be treated as a simple descent or smooth trail. Rain magnifies the effects of mud, wet rocks, and stream crossings.
“The second half was rougher than expected”
News1 reporter Lee Sang-yul, who finished in 21 hours 52 minutes, also wrote in his 100K race account that the later sections were tougher than expected. The route repeatedly dropped into passages below roads, and rain turned the trail into mud. Jeju's volcanic rocks became more difficult obstacles after dark.
As runners spread out, he spent longer periods alone. Even though the course markers and the GPX on his watch were working, the isolation made him question whether he had gone off course. A momentary loss of concentration could mean tripping on a rock or slipping in the mud.
The plan therefore needs to account for the mental work of checking the route and every foot placement in the dark, not only tired legs.
“Our energy dropped sharply after Seongpanak”
The CAYL team wrote in its 2025 TRANS JEJU Journal that the runners planned to avoid overpacing the early climbs and move efficiently through runnable sections later. In the actual race, however, their energy dropped sharply after Seongpanak. Rain-soaked boardwalks were also slippery and demanded caution.
Accumulated fatigue can appear after 60km even with a restrained start. Feeling good at Seongpanak is not a reason to make an optimistic assumption about the remaining pace.
Wet rocks and stream crossings remained in the final 20km
The UltraNomades TransJeju 100K recap describes more than 20km still remaining at CP7 around 83km. On exhausted legs, the runners had to negotiate slippery rocks and swollen stream crossings. Long descents had already damaged their legs, and their rhythm continued to fade.
Taken together, these reports show why I should not treat the final 45km as fast forest road. Seongpanak is the end of the biggest climb, not the end of the difficult race.
My plan after Seongpanak
I will keep checking these four times after leaving Seongpanak.
| Point | Distance | Target time | Plan |
|---|---|---|---|
| Eseungak Oreum | 71km | 17:40 | Check lighting and equipment around sunset |
| Camping Site | 82km | 19:55 | Avoid sitting too long and stay focused at night |
| Healing Forest | 92km | 21:45 | Keep 1 hour 45 minutes for the final 12km and 2 hours 15 minutes until midnight |
| FINISH | 104km | 23:30 | Arrive with the 29-minute emergency reserve intact |
What to do at Seongpanak
- Turn on the headlamp before it becomes too dark.
- Refill water and calories without lingering unnecessarily.
- Check socks and feet. If they are wet, make a quick decision about changing them.
- Do not increase the target pace to 71km based only on the elevation profile.
An UltraNomades runner called skipping a five-minute stop to deal with wet socks and shoes the biggest tactical mistake of the race. A small problem can exact a price for several hours. Rather than cutting every aid-station stop, I need to decide whether a short fix will save time later.
Reduce mistakes at night
Late in the race, a fall or a stop to confirm the route can cost more time than a controlled pace. I will shorten my stride over rocks and mud and use both course markers and my watch GPX when running alone. Even when following another runner, I will continue checking the markers.
The headlamp's beam coverage and operating time matter as much as maximum brightness. The official 2026 mandatory gear list requires two headlamps and spare batteries or a charger. I plan to keep the second lamp where it can be reached immediately rather than burying it as a backup.
Seven times to remember
Instead of memorizing the entire table, I will put these seven times on my hand or pace card.
| Distance | Point | Target time |
|---|---|---|
| 20km | Yeongsil | 08:20 |
| 28km | Eorimok | 09:55 |
| 41km | Gwaneumsa | 11:20 |
| 59km | Seongpanak | 15:50 |
| 82km | Camping Site | 19:55 |
| 92km | Healing Forest | 21:45 |
| 104km | FINISH | 23:30 |
Reduced to three, they are Gwaneumsa at 11:20, Seongpanak at 15:50, and Healing Forest at 21:45.
Rules I will follow during the race
I will not chase time over the first 28km. I want to protect my quadriceps on the descent to Eorimok and keep the Gwaneumsa climb below the effort that strained my calves at Taebaek. I will not raise the pace suddenly at Seongpanak just because both Hallasan crossings are complete.
Rain may make the later targets difficult to meet. Even then, I will not try to bank 30 minutes on the early mountain sections. Wet rocks, mud, and stream crossings require a slower pace for safety, regardless of fitness.
My plan fits into one line:
Start at 5:00 AM, reach Gwaneumsa at 11:20, Seongpanak at 15:50, and Healing Forest at 21:45, then return to Jeju World Cup Stadium at 23:30.
The 23:30 goal is not about chasing a result. It is a plan to finish before 23:59 while keeping 29 minutes for the unexpected.
After the race, I will compare the actual checkpoint times with this schedule and record where I gained or lost time.
Sources
- Official 2026 TransJeju Jeju100K information
- Official 2025 TransJeju 100K ITRA results
- 2025 TransJeju 100K UTMB Live results — official checkpoint splits for Donghyun Kim, Vachira Tongrow, and Juwon Kang
- Run Juwon YouTube channel — main distances and elapsed times transcribed from a 2025 TransJeju 100K video
- Anggriawan Sugianto's 2025 TransJeju race report
- Nozomi Sasaki's 2025 TransJeju 100K race report
- News1 reporter Lee Sang-yul's 2025 TransJeju 100K report
- CAYL 2025 TRANS JEJU Journal
- UltraNomades TransJeju 100K race recap