Report: OSJ Ontake Ultra Trail 100K

Last weekend I took part in my first 100km race, the OSJ Ontake Ultra Trail.


It came a bit too soon after the Utsukushigahara 80K, and I wasn’t particularly up for it, especially as it started on the stroke of midnight when I’d usually be fast asleep in bed!

I opted to start at the very back of the 1,000 runners, intending to follow a very conservative race plan that totally lacked ambition, but would see me cross the finish line inside 20 hours and qualify for Japan’s premier trail race, the UTMF (Ultra-Trail Mount Fuji).

I quickly passed people at the start, but within five minutes realized I was well overdressed in my Goretex jacket so stepped aside to take it off and strap it to my little backpack. When I rejoined the race, I suddenly found myself at the very back with the sweeper car right behind me!

I was surprised at the quick, early pace, but got back among the runners when the road got so steep that everyone started walking.

Truth be told, I run very little. Most of my “trail running” practice is really fast hiking. I think I’m quite a fast walker, at least compared to the people at the backend of a race like this, but I’m sure the guys at the front are actually running up the hills!

So I started power hiking up the first of many long hills. The forest roads were steep and rocky, but they were still roads after all, nothing like the trails I hiked over in my last two ultras. If anything, the hardest sections were the runnable parts because of the risk of tripping.

I was surprised by just how much running we were doing, but was pleased to reach the first aid station (24km) well ahead of time. I was also surprised by how crowded it was. There must have been 150 runners lined up waiting to either refill their water bottles or use one of the few toilets. I had already stopped for a couple of leaks along the way and still had plenty of water so decided to just run right past the aid station. It was a great feeling moving 150 places up the field in a matter of seconds!

Three things stand out in my mind from this stage of the race: a majority of runners using hiking poles; one guy running in sandals; and some gorgeous female runners, the kind you’d see on the cover of a fitness magazine!

After four and a half hours of running in the dark, I was able to put my headlamp away and listen to the birds sing. There wasn’t much of a view as the trail was a corridor with a wall of trees on each side, but eventually we rose above the trees and to the first cut-off gate (33km). It was 5am and I was a whole hour ahead of the time limit. This aid station was also crowded so I just grabbed a slice of banana, stretched a bit and got moving again.


Even though it was a 100km race, the only number in my head was 66. That is how many kilometers I had to cover to reach my drop bag at Aid 4 and I was already halfway there! My drop bag was filled with goodies that I was more excited about than the finish line itself, but you’ll have to read on a bit to find out what I’d packed. 😉

Since kilometer 25, the blister on my little right toe that hadn’t fully healed after Utsukushigahara was stinging. This time I had taped it up, but that obviously wasn’t enough. Not wanting to be a big baby about it, I just ran on.

Well, I walked a lot. To ease the pressure on the blister I had to lean on other parts of my foot, and doing that never ends well. I walked into Aid 3 (47km), filled up my bottles for the first time, and walked out of Aid 3.

The next section was alongside a beautiful river through the valley. I continued to walk, feeling very heavy-legged and sore from the waist down, but I’ve had low points like this before and know that when the going gets tough it’s time to put on the iPod and do run-walk intervals with my stopwatch.


It was a long way to the second cut-off gate (65km), but I finally got there a full two hours ahead of the time limit! That meant that I had five hours to reach the final cut-off gate just 17km away. And even better than that, I was just handed my drop bag!

In my drop bag I had packed my hiking poles (hooray!), pain killers (hooray!), a Snickers chocolate bar and Monster energy drink (double-hooray!), clean socks, a fresh t-shirt and a new supply of Clif bars and Trail Mix for my bag.

My priority was to sort out my toe. I’ll spare the grizzly details and just say that it was really, really bad. I had my first aid kit so did the best job I could of treating it, and got on with the race.

Checking my watch, I spent a whopping 36 minutes in Aid 4. Fortunately, time was no longer a concern and I certainly felt recharged.

It wasn’t long, though, before I had a terrible need for some bowel movement! I would never make the next aid station and wasn’t going to go back to the last one. I tried to hold it, but no, I had to find a bush. Again, I’ll skip the details other than to say that there aren’t many bushes to hide behind when you’re running on a cliff face. I smiled at the other runners as they went by, my upper body clearly visible over the small bush I found.


I soon met up with Aoyama-san, who I ran the KA50K with in February. He had hurt his knee and was walking. We chatted for a good hour about various races and November’s OMM Japan which we’re both doing, then when his friend caught up I left them together and started to run again.

It occurred to me that I could break 16 hours if I ran. So that’s what I did. The pain killers were working and most of the day’s climbing was behind me. I raced down the hills until I caught another guy running, Matsuda-san, who just so happens to live in Kakamigahara like me. We ran together, chatting about our local courses and whatnot.


82km into the race and we reached the last cut-off gate. We had a tiny cup of Coca-Cola supplied by one kind individual who had set up her own private aid station with a mouthful of Coke for each of the 1,000+ runners. Many thanks to her. It was disappointing that OSJ, the race organizers, couldn’t provide such tantalizing refreshments themselves. They did give us a small bowl of rather tasteless noodles, which I was very grateful for under the circumstances.

18km to go with three hours to do it if I was to finish by 4pm, breaking the 16hr barrier. I asked Matsuda-san if he was up for it. He had some knee pain and now both my little toes were blistered, but we decided to give it a shot.

We ran, and walked, and ran again. Most of the conversation was now focused on how much farther we had to go and whether we’d make it in time. It had been a hot afternoon, but suddenly there was a very nice breeze. I joked that this might be followed by a storm, and we both laughed nervously.

Sure enough, within minutes the sky turned dark and it started to rain, absolutely bucketing it down. There was nowhere to shelter so we, and the few runners around us, rushed to get our rainwear out of our packs. I smiled, knowing that my Goretex jacket that I started the race with would finally get used… until I remembered I had put in my drop bag at Aid 4 because I didn’t think I’d need it anymore! Fortunately I had swapped it for a light windbreaker (with water resistant properties!) so I put that on instead. Matsuda-san had made a similar mistake, swapping his hat for a visor, and now his head was soaked.

The rain was relentless and the trails quickly turned into rivers. Our feet were drenched as we waded through the water. Then, as quickly as it started, it stopped. The sun came out again and we refocused our energies on getting to the finish. I learned later that there had been no rain at all at the event ground where my friend, Yoshio, had already finished. That’s mountain weather for you.

We had been slowed considerably by the rain, more hill-climbing and aching limbs. By the time we reached the last aid station at 94km, it was 3:10pm. We took off our jackets and I told Matsuda-san I was going to run for it. The poor guy was clearly tired, in pain, and 6km in 50 minutes was asking too much. I promised I’d wait for him at the finish line and then ran ahead.

What a tortuous 6km that was. Had I been half an hour earlier or later, I could have gently strolled it, but no. I had this 16hr target embedded firmly in my mind, and the only way to achieve it was to run as hard as I could for 50 minutes. The road felt long and I thought every roof I saw in the distance was the sports ground at the finish, but I was wrong every time. I kept looking at my watch. Was it fast? Was it slow? Was the distance really 6km or 6.9km? I kept pushing.

Finally, I could hear the loudspeaker and then saw the finish gate up the hill! 12 minutes to go, but wait, the road turned away from the finish and made us climb the hill the long way around. Four minutes to go!

I was so close now. I turned into the home straight and people cheered for me! The music was blaring and the guy on the loudspeaker was egging me on. I reached for the sky and let out a huge “woohoo!” as I crossed the line in 15 hours and 54 minutes. (Turns out my watch was a bit fast after all!)

Matsuda-san came in about 20 minutes later and we congratulated and thanked each other. We had both completed our first 100Ks and had qualified for the UTMF, or at least earned enough points to enter. Entry is a lottery so there’s no guarantee either of us can do it.


Aoyama-san also finished and earned his points. In fact, everyone I know that took part finished. Yoshio, who I had driven up with, finished in under 14 hours, qualifying him for the 100 mile version of the day’s race should he want to do that next year.

My next race is OMM Japan in late November.


Most photos kindly borrowed from Aoyama-san. Others are from various Facebook acquaintances. 🙂

If you like, you can find me on Twitter at @nick_ramsay. I'd love to hear from you!

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